Home Page of Our Unimog CamperProject
Old Testament Psalm 100, A psalm of thanksgiving:
- Shout with joy to the Lord, all the earth!
- Worship the Lord with gladness. Come before Him, singing with joy.
- Acknowledge that the Lord is God! He made us, and we are his. We are His people, the sheep of His pasture.
- Enter His gates with thanksgiving; go into His courts with praise. Give thanks to Him and praise His name.
- For the Lord is good. His unfailing love continues forever, and His faithfulness continues to each generation.
Is Jesus God? John 10:29-30 …29 "My Father who has given them to Me is greater than all. No one can snatch them out of My Father’s hand." 30 "I and the Father are one.”
First thing to say is that I do not present myself as a professional in the field of motor vehicle conversions, and any information you act on, is at your own risk. This information is aimed at persons already with considerable breadth of both engineering and practical trade skills in the relevant disciplines/trades. I'm learning as I go like most other first time owners of such a truck, and I'm making my fair share of mistakes. When its over my head I go to a professional.
Definition: The term 'truck' in Australia refers to a large commercial vehicle (a lorry) and not small utility vehicles which the Americans tend to call trucks.
Its easy for anyone with too much money and little or no imagination, to simply pay someone else to build their special project or buy it off-the-shelf (and they usually do). The most value however, can sometimes be in the actual journey of developing and using your own skills and imagination in order to enable the most cost effective solutions. However, there is always a price to pay with DIY and usually its time (and sometimes damage to health). Pay someone and yes its quick. Do it yourself and its likely to take a lot longer (and you may need to learn the trade , develop the skills and purchase expensive specialized tools). You may make lots of mistakes, I did and still do, but I learnt a lot from them. A big advantage of refurbishing a rig yourself, is that you learn about it. You get to know how it works, what tools and tricks are needed, where to buy spares in a hurry, what tools to pack with you on a trip, potential problems (eg: did you over torque a bolt and now its in the back of your mind niggling you) and most importantly you will likely learn how to fix some things when in a tough situation in the middle of woop woop.
This site is an ideas education site about my experiences with the design, construction & materials sources for my hobby, the refurbishment of an ex Australian Defence Force (ADF) Mercedes Benz Unimog U1700L. I am grateful to the Mercedes Benz forum https://www.benzworld.org/forums/unimog.39/ of experts from across the world who lend their knowledge and time to helping others. Without their help, I would have been proverbially stuffed.
Above is the Tonka toy in the front yard, on the day I drove it home from Minto (outside Sydney), condition unknown, October 2017. As I don't plan to go hiding in the outback any time soon, I've gone away from the standard camo paint job. If war breaks out, maybe I will revert back to camo colour scheme. In the mean time, I need to get it Heritage registered. In order to do this, I can choose from a couple of actual colour schemes, Army, Airforce, or United Nations. UN seems the way to go. When I put a 'comms' box (camper) on the back, it will be white also. I have replaced some items with polished stainless steel bling for longevity, but which are not kosha. These items can always be reverted back to painted and rusty steel if needed.
Whilst the UN has much to be ashamed of by its sometimes inaction(eg: Rwanda genocide: In just 100 days in 1994, some 800,000 people were slaughtered in Rwanda by ethnic Hutu extremists), I am not ashamed to reflect the UN colours because it exists to try and do good.
I am doing most of my own vehicle maintenance rebuilds and upgrades. Having once run my own hands-on electrical engineering business for some decades, owner-built two challenging homes on steep sites and extended another, its now about the engineering process. I can say that an expedition vehicle build project is not for the faint hearted. I'm learning that its akin to designing/building a complex bespoke home. My 'owner-builder' home builds each took 10 years on average to get to a comfortable stage, this project has so far taken 5 years trying to make a silk purse out of a sows ear. The cost of buying a comfortable 'ready made' all-terrain camping vehicle however, is going to be prohibitive on most working class peoples income (certainly for me as a Pay As You Earn). In my case, I have selected the military Unimog as the platform (simply because they are being auctioned off in a once in a lifetime affordable opportunity here in Australia). So if you want a long term hobby project refurbishing a ~30 + year old military truck (be it humble and austere as in the Unimog) and hopefully some fun along the way (for some), read on. It can also be hard dirty and sometimes painful health damaging work if you don't watch yourself, but if you aim for nothing, you will surely get there.
I hope this knowledge site will provide some useful ideas and information for those who might aspire to a similar hobby and have the necessary hands-on skills (plus you will need deep pockets). This site also includes information and ideas from many wise and knowledgeable people who have gone before me. I do recommend the Mercedes-Benz forum (https://www.benzworld.org/), whose Unimog members across the world are very knowledgeable, have been though just about everything one can think of before, and have been only too happy to help a newbie like me wherever they can. The members of this forum are professional and have set me on the right path time and time again when I have been stumped.
There are also some helpful Unimog sites on Facebook where you can see photos of other peoples rigs to get ideas. These facebook sites don't usually deal with serious technical issues, but are a useful source of general info and sources of parts. Some sites are:
- Unimog Owner's Group Aus.
- Unimog Owners Support Group Queensland
- Unimog and expedition camper
Military platforms (if you can get them), are good for their robustness and ground clearances and can go places that typical motorhomes and domestic 4x4 vehicles cannot. Motorhomes or coaches are typically built on a standard medium or light truck chassis and this confines them to highways or well graded flat dry dirt roads. I have spent time over the years working on a Winnebago etc and found that they also are on a standard truck chassis's. Most of these vehicles as well as the domestic 4x4s vehicles (even my Land Rover Disco diesel) are lucky to have barely 200mm of underside clearance. That's not going to cut it under some less than ideal situations that one might come across in the Australian bush. Even if you are as conservative and risk averse as me, when travelling across Australia the most likely issue aside from potentially crashing into the odd bullock, camel or other wildlife, is coming across a suddenly flooded track or creek bed crossing. This is when the Unimog ATV should come into its own.
As in the case with the USA, the Australian Defence Force (ADF), is busy divesting itself of life expired fleet and upgrading with faster lighter more agile multi-function vehicles. The US have some very nice vehicles being auctioned also, but I found out that only US citizens are allowed to buy and export them. So its easier to just buy local. Not for 30 years has such a good opportunity presented itself for ex-military vehicles in Australia. I am very glad that the government took the stance to sell locally and not ship them off to overseas governments (as was one option being considered).
You should go into this with your eyes open, some of the downsides to buying a life expired military vehicle such as the Unimog are that:
- parts can be difficult or impossible to obtain (as its often a bespoke build for the particular country of use). You will be spending a lot (and I mean a lot) of your time searching the internet for value for money parts and information. Likely every night for some years....
- vehicles are usually close to life expired at about 30 years old (they don't get rid of them cheap for no good reason). In other words, they are starting to cost more to operate than they are worth. Even with well maintained vehicles, some of the rubber and plastic components etc may have started to perish, engine/drive train seals starting to leak, etc. Its buyer beware,
- vehicles are usually very heavy which can be an issue at some locations (good chance of getting bogged),
- top speed is often only 80 to 90km/h (which means high revs and high fuel consumption to try and keep up with traffic on the highway). They are geared low (designed for torque, not speed). This means a slow vehicle,
- they are designed to be very austere, very functional and not the slightest bit comfortable (just the opposite) this means a lot of work to make them comfortable,
- engineering certificates may be required for modifications,
- very noisy, and
- operating costs (especially fuel) can be significant (to say the least) due to the low speed ratios and low manufacturing volume of spare parts. For example, window felt guide for a car is typically about A$9/m for the majority of domestic vehicles, but the Unimog genuine part is about A$80/m. Is it 10 times the quality of most other vehicle makers equivalent part?, I don't think so. I ended up buying the felt strip from Clark Rubber (took a long time to find the right profile however).
- parts are generally expensive compared to your run-of-the-mill Toyota 4x4.
According to an Australian ADF fleet replacement strategy publication in 2014, the average annual cost of sustaining the life expired Unimog was $10,652 and $27,899 for a larger vehicle such as the Mack. In other words, this tells us that when buying a close to life expired vehicle, its likely to cost a lot of money to keep it on the road in a safe condition (beware of Romulan's bearing gifts). The report also states that some parts are increasingly hard or impossible to obtain. Further, the ADF in their disposal and fleet purchasing strategy, state that the hierarchy of vehicle disposal is to get rid of those which are costing them the most to maintain, first. What I make of this, is that these vehicles are not going to be cheap to get up to spec and then keep on the road (and if not a fortune by paying 'others' to sort them out, then potentially thousands of hours of your own time). From my observations of Facebook sites, most people have no idea what they are getting into, they buy them because they are cheap, and likely, will just run them into the ground thinking them indestructible. Some however, will strip them down and rebuild them evenbetter than new. I'm trying to take the middle road.
A useful source of information when inspecting the trucks pre-purchase, is the vehicles 'Service Record Book' (if it has one). At the time I purchased my vehicle I was not aware that also, there is a recent 'Technical Inspection Report Vehicles' slipped into the book which details some identified problems. At the very least, its worth reading this brief report if you don't have time to scan the entire life history of the vehicle. You will need to ask at the auction inspection location desk, to look at the books.
Some of the more common ADF variants are shown below (source: ADF public domain Maintenance Manuals):
I have no idea as to whether some of the more weird variants as shown above, will eventually come on the market.
My view of some categories of ATV platforms:
I would have liked a 6x6 recovery Unimog due to the possibility of installing a longer living module, but practicality took hold and I ended up purchasing a 4x4 UL1700L/38 flat bed without crane. The 6x6 are whats termed 'protected'. They are not to be sold (at least not yet).
I am refurbishing, re-painting, modernising, upgrading, adding security, comms, long range fuel tanks, storage boxes, engine/ drive train management systems, air conditioning and finally one day, integrate a reasonably comfortable living module and then, hopefully, start touring. Its a long term plan, likely to take at least 5 years as I generally only work on it part time (weekends). I have spent about 5 years so far including design, sourcing and purchasing of materials. Its a big job, as just about everything needs refurbishing. Nearly every bolt is surface rusted, every panel has marks and dents, every wiring connection is suspect, every bit of painting quality is poor, all sorts of inconsistent dodgy fixes, odd screws, torn upholstery, cracked plastics, every glass panelscratched, degraded/perished rubbers, surface rust, rotted timber tray, etc etc ......... I must have replaced hundreds of bolts and I try to use stainless steel for the non structural applications. A lot of the structural larger bolts are grade 12.9 but which are difficult to get in Australia from OEM unless you buy Mercedes genuine.
At this stage in my life, its more about robust engineering rather than fast cars or bikes and yes, its essentially a tractor (the equivalent to the Harley Davidson motorbike). Rego with insurance seems to vary from state to state. It cost me ~$4k to first register it, but I may have stated the higher tonnage towing value to cause this? In NSW there is now a Heritage vehicle registration option (which is super cheap), but the vehicle has to be kept fairly representative to comply. It can have non periodsafety changes done however.
Unimog General info
Unimog is an acronym derived from the German “UNIversal. MOtor Gerat“, or all-purpose machine. Its a slow moving vehicle (based on a tractor), but very strong, the military version having a militarized commercial engine and drive train. The older square cab series is known as the 435 series. The U1700 is a medium battlefield truck. Any parts and materials I nominate herein are for the Australian military U1700 version (in my case the U1700L/38 / UL1700L) and they may not suit any other version and its up to you to check the validity yourself anyway. I suspect that most of the thousands of military U1700L's in Australia are essentially the same, with various options such as: winch, tyres, tip tray, flat tray, crane, radar disk, shelter cubicle. There are even a small number of dual cabs and a number of 6x6 recovery versions which are 'protected' (not supposed to be sold, but one did, supposedly by mistake). They apparently all came out of the same Victorian Benz Daimler factory (as I understand).
Basic data for my derivative, U1700L:
- Manufacturer Daimler-Benz
- Australia Army second line transport (medium size)
- Max load carried is 5 tonnes
- Ground clearance 460mm
- Mass unladen 6.8 tonne
- Maximum total loading 12 tonne
- Maximum legal loading with trailer 21 to 24 tonne
- Fording depth 1.2m
- Turning circle 19.6m
- Angle of approach 39 degrees
- Maximum gradient 60 degrees?
- Gross combination 24.5 tonne
- Fuel (standard arrangement) 25L/100km
- Engine OM 353.939 (OM 352a)
- Automatic load dependent brake
- Air brakes
- Voltage 24V
- Trailer socket NATO 12-pin
- Winch 62kN. Cable length 30m x 14mm
At a time when many vehicle makers adopted independent suspension – including most military light truck makers, the Unimog stuck with live axles, because of their superior wheel travel and tyre contact on highly uneven surfaces.
However, the military sees an advantage in independent suspension, because a land mine can blow off one wheel and the vehicle may still be driveable. Of interesting note: the modern Unimog (likely with modifications) has been used to shunt up to 1000 tonne trains around rail yards (cheaper than buying a shunting locomotive) so you can get an appreciation of the low down torque available. But it will be moving veerrrry slowly and with a big weight on the back to get the traction needed.
First things First
Based on my experiences: I strongly recommend the following things should be inspected asap once you get your toy home:
- Check condition and level of all fluids.
- Check braking system for hydraulic fluid leaks.
- Flush/clean out the pneumatic system of rust and crude. If possible, fit a water removal system just after the compressor.
- Check that the rear park brake air actuators are functioning properly and in a safe condition. They will likely need removing and stripped down to do this properly. Warning: There is a large (potentially dangerous) spring inside.
- Inspect the brake disks and condition of brake pads. Pads will likely need removing to do this job properly.
Caution: The above activities in bold should only be done by a professional person with competencies in the appropriate field of vehicle maintenance/engineering.
The first stage for me, was setting up a work shed in my yard, planning the overall build and design in as much detail as practical for a couple of years, buying tools, materials and equipment and constructing any sub-assemblies where possible, ahead of time. As I live in suburbia, the local Council will not permit sheds or carports tall enough for caravans or trucks, so most of my work is done outdoors depending on the weather.
If you are like me (without a proper machine shop), it may mean fabricating the smaller parts and getting the larger parts fabricated by professionals. I often make up most small fittings, tack the more complicated items and then take them to a local professional for full welding (such as Beauchamp Metals at Kirrawee in Sydney).
I plan ahead in as much detail as possible as this enables me to keep an eye out for the right equipment at the right price. I regularly search on-line auctions and generally only stick to auctions in Australia now (as I found out the hard way, that crating, transport and Customs fees can be high). In fact even auctions in other states can be prohibitive as the packaging and freight costs can easily make it not worthwhile. Unfortunately with a military platform, nearly everything has been, and has to be, designed and built bespoke. With such a project, its a good idea to start becoming familiar with the relevant state and Commonwealth Heavy Vehicle Regulations pertaining to modifying a large motor vehicle.
The National Heavy Vehicle Regulator (NHVR) administers apply the rules for heavy vehicles over 4.5 tonnes gross vehicle mass. The HVNL consists of the Heavy Vehicle National Law and five sets of regulations.
The learning of new skills, trades and understanding of compliance's can be daunting, but if you don't start somewhere you may never start at all. I find its a matter of plodding along and learning new things, one step at a time. Rome was not built in a day and whatever time you estimate, double it.
- Winch refurbished and painted. Done.
- Dyneema 14mm winch cable. Purchased.
- Rear park brake and main brake actuators removed, refurbished, re-installed, tested. Done.
- Air tanks etc removed, cleaned up coated inside with epoxy sealer, re-installed. Done.
- Original seats removed, adapter bases made & new seats installed. Done.
- Cabin roof lining and internal odds refurbished.
- Added auto drier filter/drain system to air. Done.
- Front guards panel beated as new. Done.
- Rear guards panel beated as new. Done
- New steering wheel and hub. Done,
- Straighten front grill. Done,
- Small weld required in roof and passenger door. Done.
- Soundproof underside and inside. Done.
- Strip out cab and doors and replace most rubbers. Done.
- Repaint cab (inside and out). Done.
- Repaint underside of vehicle chassis (drab olive). Done.
- Manufacture fuel tanks hangers and adapter brackets. Done.
- Fit long range fuel tanks including piping and level sensors etc. Done,
- Relocate batteries under bonnet. Done.
- Replace barge board frame with heavy duty one. Done.
- Add front underside protection crash bar. Done,
- Locate drab olive canvas and have covers made for air conditioner, mast lights and winch. Done.
- Roof rack frame. Designed.
- Replace belts. Done.
- Replace all filters. Done.
- Tube up new low pressure air systems (for: air horns, seats, tyres and telescopic mast). Done.
- New turbo. Done.
- Add turbo intercooler. Done.
- Replace exhaust with stainless: new muffler and vertical stack. Done.
- Add set up for tilting the cab safely (hydraulic ram). Done.
- Design/install custom tool boxes front of rear wheels. Done.
- Replace cab steps with stainless arrangements. Done.
- Fit 11m telescopic pneumatic lighting mast to barge board on passenger side. Done.
- Engine / drive train: monitoring/warning systems. Equipment purchased, partially wired up.
- Air conditioning (with compressor fitted under bonnet). Done.
- Headlights refurbished . Done.
- Remote door locking modules installed. Done.
- Security module. Done
- Black box video and data logger accident recorder and remote control module. Done.
- Wire up electrics. Mostly finished.
Removed unwanted side mounted items (spare wheel, battery box, tool boxes, fuel tank etc). Stripped down air system, added air filtration system. Cleaned up , removed surface rust, loose paint flakes andstarted painting.
Designed/fitted hydraulic piston cab lift system.
I made up an adapter bracket (shown in brown) to fit a standard 600mm ram (shown in blue) to the lower pivot point. All up, materials: about $150. Tricky to ensure manual pump handle does not foul anything and the control valve is accessible. I had intended for the ram to sit within the two forks top and bottom, but due to the sway bar, had to use long bolts to offset it. Still works fine. It only takes the cab up to about 30 degrees but this is sufficient for me to do most work (short of removal of the engine). It's also good for me, as it is not so high that the steering shaft pops out from its socket, as its a two person job to align it for lowering the cab and I don't have a helper (the wife refuses to have anything to do with it!). With the pneumatic option, its quick and easy to raise and lower. There is no need to have a safety cable, as the cab can never exceed the rams limit. But it is a must, to have something to stop the cab dropping down. I fitted a safety stop brace (as shown in yellow), rated at about 12 tonnes. I also put a length of timber in place (belts and braces approach).
Finished cleaning up and painting the hubs with epoxy paint and fitting MRAP style wheels. The only way for me to safely move the new wheels was via the engine crane and a chain cage (same set up as snow chains) as shown below. I'm 5' 10" tall, so you can see that these are not small wheels. Note the size of the standard steel rimmed wheel sitting behind it. New longer studs were required for the alloy rims. Checked for wear or leaks, general clean up, grease, adjusted brakes and repainted portals, new pads at the rear. Added stainless steel magnetic oil plugs in portals. Used high quality synthetic oil. Noticed a slight weep at both rear portal seals afterwards? About a drop per 6 months. I have heard stories that it might be due to synthetic oil being used? Might also be simply that my new magnetic drain plugs are not sealing up fully onto the copper seals.
New fuel tank support adapter brackets fitted on both sides (tricky job utilising only existing bolt holes in the chassis rails). Had hanger brackets made by Hilton Industries (to suit stainless tanks).
Now that the cab is lifted, started on the engine bay. After removing the exhaust pipe from the turbo outlet cast iron section, I observed that the exhaust brake butterfly valve was not sitting fully open. I found that all linkages need work to clean, paint, adjust (take out slack). Where there is wear on shafts, additional bushes and end thrust washers may be needed to bring them back to new.
Removed the cab underside anti-stone chip tar coating that was not solidly bonded. Good that I did, found that rust had started to hide under it in one corner of the floor. The only practical tool for removing this thick coating is the pneumatic needle gun. It is perfect also for removing heavy paint eg the dozens of layers on the portals/hubs and the winch with the curved surfaces (takes it back to the original primer).
Its Nov 2018 and I have recoated the underside of the cab with a synthetictar like coating. New turbo is in and tested ok. Made up exhaust pipe in stainless, tacked together, modified new muffler and installed.
December 2018 Christmas break.
Fabricated brackets and bolted air conditioning compressor under the bonnet. Worked out gas fittings and parts needed for air conditioning system. Brought in Red Dot items from USA and fitted Condenser on roof with stainless bars and bolts etc . Discovered that the in-cab evaporator at the front of console position fouled the gear shift lever in 1st gear. Had to ad-hoc make up new bracket for mounting it off the rear wall between the seats instead. Probably a more sensible approach anyway, as it will leave me space on the centre floor to walk from one side of the cab to the other, and for the dog to sit on the floor in the centre.
Prepared cab, front chassis area and winch for painting (lots of sanding and priming due to 32 years of layers of paint over paint). Removed roof hatch for priming. Replaced numerous bolts with new. TIG tacked the vertical smoke stack together. The professionals at Beauchamp's Sheet Metal fully welded it up for me. Cut all the unwanted superfluous brackets off the walls inside the cab.
TIG repaired 2" splits in roof and door. These were caused by the ADF maintainers over sanding the paintwork on the metal edges eventually wearing through the metal !
Painted front chassis and inside/roof of cab. After weeks of filling stone chips, hand sanding and removing loose flakes, I eventually gave up trying to fix the hundreds of stone chips and overspray blobs and runs. Ended up with a few runs myself.
Installed the Caterpillar heavy duty air ride seats made by USA Sears Seating.
Fitted up the newly painted front underside bash plate (sump guard). Then discovered that I cannot get to the steering pump, so its got to come off again (so I can get a long leverage bar onto the oil pump mounting pivot). Drilled lip of bash plate and installed an air pressure dam using conveyor belt material. The air dam theory is that it creates a negative pressure area at the lower rear part of the engine bay, thus more air flow down past the engine. Apparently only tends to be efficient at higher speeds however.
Removed door lock mechanisms, washed re lubricated lithium grease spray. Removed window guide felts. Installed sound foam and fitted cabin rear wall panels. After trying many profiles for the window slide felts, I eventually found a version from Clark Rubber which worked fine.
Mid 2019 Progress
Designed extended head (barge) board frame and had it made by Beauchamps.
June, TIG'ed the frame into place and the telescopic mast support brackets.
Fitted Unidan intercooler kit. Note: Its a good kit and if you buy one, read the instructions very carefully. I jumped in, and had to take parts back off again (more times than I want to admit) to get the parts in the right order. I welded a 4mm thick plate to the aluminium tube just before the engine air entry point and drilled a hole in it for the Auger boost pressure sensor. The main issue for me, with the kit, was that I had to trim a fair bit off the bottom of the front grill, Its a tricky job to trim the grill but turned out fine.The intercooler radiator is shiny aluminium, but I eventually painted it black (using radiator paint) so that it does not stand out.
Australia Day weekend 2019
Filled some of the cab box section cavities with expanding foam but not all, (need to allow for condensation drainage holes). CAUTION: foam may continue to ooz out of a hole for some hours.
Made up custom brackets and mounted Evaporator inside cab. Only just fits with a few mm to spare from arm rest. Made the polished stainless exhaust stack heat guard (unreasonable prices to buy). Starting to make up the 316 mirror polished steps for the cab entry see photos below. Need to be wide and stable so my wife can feel more comfortable using them.
Finished installing additional idler pulleys for the new air conditioner compressor belt and one for the fan belt. The fan, water pump, generator and A/C are all driven by one belt from the crank. I will likely need to change this, such that the A/C has its own belt from the crank (as it draws a couple of horsepower). These are long belts and tend to vibrate, so the additional idler pulleys remove most of the bounce. Also, after running for a while, they will stretch and bounce even more. I have re-tensioned my new belts more than twice and the vehicle has not yet left the lot. Getting the right tension is important. Letting then flop around causes them to erode (you may notice a black powder building up). The difficult one to do, is the air compressor. To replace the one at the rear, you have to remove all the ones on front. Note: To get the belt length, you can fit a loop out of rope or twine etc , and take the loop to a belt supplier who should have a machine to measure it and provide the correct belt size.
Air conditioning charged and tested.
Christmas 2019 over three week break
- Re-fitted winch.
- Painted vehicle underside.
- Wired up and tested telescopic mast flood lighting. Comms antennas can be left to later once I figure out what technology I need to implement.
- Installed lower hanging steps. After trying to buy one, I gave up and made my own using 316 stainless and conveyor belt type material (metal free). It is flexible in order to move slightly, if struck.
- Primed tray frame surrounds.
- Tidied up rear lighting wiring.
- Ran most of the outstanding wiring to inside cab (driving lights excluded), ready for later termination (big job many new circuits to terminate).
- New Years Eve: Bad day for bush fires further down south. Decided I did not like my paint job. Unfortunately I picked a bad day New Years Eve (extreme temperature so paint was almost drying before it hit the surface), then a wild wind storm in afternoon (with soot and dust) tossed some garden furniture around eventuating in a big dent in the middle of the grill.
- New Years Day: A little cooler, so did the necessary repairs on the grill, undercoated and managed to get a few colour coats before the full heat of the day. A couple of paint runs, but too bad, I've run out of patience. Also sorted out rear mud flaps.
- Started work on sorting speedo re-calibration. There is a gearbox at the transfer case (see photo) and at the back of the speedo,
- I also started to install the front wheel guard rubber extensions, but the 4m length of rubber arrived twisted and useless, see photo. I include two photos to show the difference in sunlight on the same day due to fires and smoke haze. The reason its all twisted, is because they sent me end of roll. I had to re-order from a different company but it took some time to find someone with new stock, i.e. a new roll. What finally arrived was good.
- Installed Turbo monitor and Madman engine management module into dash..
- Purchased local stainless hand rails (for use on a house, as they were about 1/10th the price of versions with the word 'truck' in the sales brochure), modified and fitted to outside of cab using nutserts. Lots of overpriced items out there, but despite my doing my homework, sometimes I still end up getting bitten and paying too much.
Anzac Day 2020
Due to Covid-19 restrictions, the neighbors and I stood at their driveways with a candle this morning for dawn service of remembrance. I drove the truck up to the top of the driveway for the morning. Very tight fit, a couple of inches each side, took out a few large branches but minimal damage that re-paint won't fix. I'm just going to have to get used to the fact that the paintwork is going to be constantly scuffed.
I think I'll paint the brush guard and put it back (even though it does look horribly ordinary andcommercial).
Drive-train and Wheels
Unimog Drive train
The Unimog is heavy and geared down low. These vehicles are intended for off road use and have a maximum speed of 90km/hr at top revs. Note that trucks here in Oz are limited to 100km/hr anyway. Running at high revs continuously over long distances will tend to chew the juice and wear the engine out sooner. If you are retired and living off savings, then fuel consumption could become a problem over time.
The U1700 can be adapted to alter the gear ratio, but at much expense. For example, its apparently about A$12k to bolt on a Claas Adaptor for highway running speed (possible ~110km/hr). I suspect that the drive shaft in this case also has to be shortened? I understand that the PTO gearbox also has to come off, that means no winch. A possible better option would be fast Crownwheel & Pinion kits for the diffs. I am hoping Atkinson Vos will develop a reasonably priced kit one day (which should be very popular here, potentially many customers).
Larger diameter tyres can also help slightly.
If you have the military tyres they will likely be G rated, i.e. you will probably be limited to 90km/hr so the primary advantage of a high speed adaptor for a Unimog is that the engine revs will be a little lower for highway running (maybe worth it for that reason?). In other words, the engine will not be running flat strap just to do 90km/hr and its life should be extended as a result.
In Australia, a wheel comprises a rim and a tyre. The rim is not the wheel.
Tools needed: In my case the stud torque is 400 to 450Nm, so I had to find a reasonable price 3/4" torque wrench up to 500Nm and an impact socket set to suit. Wrenches seem to vary from ~A$185 to well over A$1,000 but for very occasional use in changing wheels, I purchased the cheaper end unit. In removing the original wheel nuts, I had to buy a 1" drive nut cracker torque multiplier, as they would not budge even with a 1m extension pipe. Probably another good reason to replace the studs and nuts, as someone had waaaay over-tightened them.
I do recommend a torque multiplier as it might save you injury, as some of the larger structural bolts may never have been removed and can be rusted in. On the other hand, you might end up shearing off a bolt whereas patience using penetrating oil and some heat plus shock loads might be the safer option in some cases. Once you have sheared off a grade 10 or 12 bolt you are likely in trouble.
I have to say that the standard steel military wheels look likely to be indestructible and very practical. But I just don't like the look of them and the tyres are too thin. For me, its not just austere functionality, its also about the visual aesthetics. Note: when selecting rims and tyres the national heavy vehicle regulations limit how much change in offset is permitted (I think its 12mm for cars?) and in Oz, overall vehicle width must not exceed 2.5m.
There are lots of rim offsets available. Hutchinson alloy rims for example, come in two pieces, both parts have different numbers and need to pair up not to exceed the 2.5m rule or the offset rules?. You need to do your homework when buying them.
When considering upgrading to the wider tyres and alloy rims compared to the more common 12 or 13" tyre width on the ex ADF Unimog 435 series, the following additional issues will need to be considered:
- Weight (will you be able to change a wheel by yourself? I know I won't)
- Longer wheel studs needed if you change from steel to alloy rims
- Different nuts required (two piece, if you change from steel to alloy rims)
- Depending on new rim offset etc, might need a chassis lift (either fit pucks at top of existing springs or replace springs with longer springs) and/or Cab lift. Wheel guards to be extended out (either new guards or extend existing guards as I did)
- Possible extra wheel(s) for spare or use standard steel wheel(s) for spare(s) Note: If you have converted to alloy rims with longer studs and want to keep the original steel wheels as spare, you will need to keep some original conical nuts and may need to make an adapter spacer plate (which might not be legal). It can also be a legal issue if the pair of steering wheels are different. Tyre offset and compliance rules to be considered (as well as overall width of vehicle). In the end, its probably simpler to just buy the matching spare.
- Possible extra load on portal bearings due to extra weight if run-flats fitted. If different tyre diameter, you will likely need to get your speedo corrected. The truck engineer advised that this is a necessity.
- Tyre may drag on mud guard at full lock (mine did). This likely means getting the front guards re-rolled to a different diameter.
- Engineering compliance certificate likely needed if changing wheel type
Tyres can be very expensive and difficult to obtain in a hurry. If however you look after them, I am advised that they can last a long time. Aside from age, UV damage and loss of volatile organics is something you need to be aware of. Ideally best to keep the tyres covered and wrapped in cling wrap or plastic bag and place the vehicle on jack stands when not in use for extended periods. High jack stands are hard to find at a sensible price here. I was going to weld on extension pipes, but they might be unstable, so I bought a strong standard truck set and simply used timber blocks to get the right height. I've used BBQ covers from Aldi to protect the wheels from the sun, grinding sparks and paint over-spray.
The standard ADF tyres here are ~46" diameter and G rated so don't expect to go racing with them. In fact if the gear ratio is changed, one could theoretically exceed the tyre speed rating? The U1750L (typically for the Airforce) has 365/85R20 / 13R20 (13" wide) tyres and the U1700L (typically for the Army) has 12R20 (12" wide) tyres. According to an Army friend, the 12" wide tyres are a regular problem in some situations as they can easily bog the vehicle. The 13" are a little more useful but still not ideal for this weight truck off road. The 6x6 recovery version (U2450L) however, is fitted with the wider 16" tyres as standard i.e.395/85R20. Note: According to a senior army source, the reason for the three tyre widths is that the Army simply did not want to spend the extra money on wider tyres for all vehicles, and so decided on the thinner cheaper tyres for the majority of the vehicles. Wider front fenders for the 395/85R20 are difficult to find. The company which prepared the ADF U2450L's was 'Evans Deakin Engineering Pty Ltd’ and they were then acquired by the 'Downer Group'. Its anyone's guess then what happened to that group, as 'Downer' did not reply to my emails. Wider fenders are available however, from Europe.
I'm running the Michelin 395/85R20 XZL Radial. The Michelin engineers are (as to be expected), very conservative (risk averse). Their web site specification sheet (2018/2019) for this 'X Force' tyre, states (max: load and pressure):
- Road 5.6T /tyre 123psi
- Cross country 3.65T/tyre 52psi
- Sand/Mud 3.65T/tyre 30psi
These are for the tyre loads shown. The specification table does not distinguish for unladen nor for run flat/bead lock options. The local salesman told me minimum pressure was 87psi and would not change his story despite my telling him my unladen vehicle tyre loads are only about 2T front and about 1.4T rear (1/2 max loads). Obviously there are lower pressures for lower loads, but I have not yet found this data.
Anecdotal evidence from forum members seem to indicate one can go as low as 20psi in the sand? I guess I'll find out one day. I've initially set the front to 48psi and the back to 38psi for road use unladen.
The Australian military Unimog wheels are 10 stud 20" with 334mm/335mm wheel bolt centres. The army U1700L steel rim for example, is about 8.5" wide. My Hutchinson alloy rims are 10" width. The Australian military Unimogs apparently mostly have steel split rims with a sprung ring. When changing tyres with a ring, this style of split rim can be very dangerous if you do not know what you are doing and a safety cage is often required around the wheel. Not many repair shops like to, or will, work on them (so that's a clue straight away). Also, the bolts stick out and the wheel nuts are more exposed to being damaged on rocks. So far I have not been able to find heavy duty wheel nut protectors (they all seem to be paper thin decorative type).
For Hutchinson alloy rims, I have fitted wheel separators (thin 1mm plastic discs) which isolate the inside face of the rim and hub allowing for very minor imperfections and stopping the two getting stuck together.
Note: When fitting wheel nuts, I have been advised to use light oil on the threads; not grease , not anti-corrosion spray, not WD40, not anti-seize but only light oil (eg Singer sewing machine oil) to ensure one is able to achieve the correct torque. The torque value I am using is 450Nm.
Run flats & bead locks
When the tyre pressure has been reduced for soft surfaces, sand can enter around the bead and cause the tyre to leak, the tyre can come off the rim due to distortion and/or the tyre can spin on the rim. Bead-locks allow for low pressure travelling (sand etc) thus reducing the chances of a tyre slipping or coming off the rim. For some wheels, if you don't have the combined run-flat/bead-locks (or don't want them), alternatively bead-lock only rings can be fitted inside the tyre.
Some military wheels (MRAP) from the US come with the combined 'run-flat/beadlock' inserts. The run-flat in the MRAP wheel is designed (so I am advised) so that the wheel can be run at up to 50 km/hr for a distance of up to 50 km while the tyre is flat (I imagine there would not be much of it left after doing that). However, if the lube has dried out, the tyre will be damaged well before the above speed and distance values are achieved. I was considering for a long time as to whether I should remove the run-flats. But after recently talking to a tyre expert in the area, I have come to understand that the main advantages are that:
- if you get a blow-out at highway speed, you are much more likely to have a better chance of keeping control of the vehicle whilst pulling over. This is because the tyre cannot delate to 100% (see my photo further on), so its effectively still kept up (to some extent) by the solid donut rubber run-flat inside.
- if you get a flat in an awkward location such as a river bed or sand dune, the run-flats allow you to drive a considerable distance without air in the tyre. The tyre will probably be wrecked after driving a considerable distance, but at least you can get to a safe place to deal with changing the wheel.
- as the Hutchinson run-flats also function as bead-locks, they reduce the opportunity for the tyres to spin on the rim when the tyre is deflated for soft surfaces.
- As the tyre cannot fully collapse, the tyre is less at risk of being damaged by driving on it.
The main down side as I see it, is the unbelievable extra weight, and thus increase in fuel costs and increased wear on portals. Be aware that these wheels are almost solid rubber and almost immovable for the average person due to their extreme weight (even on a concrete surface). Hence you might have buckley's chance of changing a wheel on a loose surface by yourself? Also, when the air is let down for soft surface, the tyre may not bellow out sufficiently for the conditions (but I don't know, as I've never driven on them).
For the Hutchinson military run-flats, I have been advised of the following by the manufacturers:
- Heat Retarding Lube is absolutely needed inside the tyre if you expect to run them flat for an extended period.
- If the lube leaks out or dries out or you replace the tyre, the lube needs to be replaced or the tyre can catch on fire if running an extended distance with no air.
- My size tyre requires about 48 ounces of lube and its not cheap.
- The lube is applied as a paste to the inner liner of the tyre under the belts on the crown. Unfortunately it cannot be inserted through the air valve and to get it into the tyre you will require specialised machinery to strip, re-fit the run flat and re-assemble.
Note: a special replacement 'O' ring is used to seal the two piece alloy rim. The proper Hutchinson version of the'O' ring is made of fancy materials so as to last in extreme temperature conditions. I am not sure if an 'O' ring can be re-used again, but if its in good nick I suppose its at the owners risk. Sounds like its a good idea to carry a few on trips. Hutchinson military rims, parts, repairs etc (including 'O' rings and lube) can be purchased from local company, Marathon Tyres. I am advised by Marathon Tyres that their:
- 'O' ring part number to suit this rim is Part Number: 50015
- heat retarding lube to suit this rim/wheel/run-flat combination, is Part Number: 500280
Assembly Bolts: Caution: When the assembly of (peripheral) 24 nuts are undone, the run-flat apparently tends to want to expand out suddenly and pop the face plate out. This can be a safety issue. When re-assembling the wheel, the donut run-flat needs compressing in order to re-fit the face plate. Some owners (I am told) fit longer bolts at every second hole as standard, as the odd longer bolts allow some nuts to be screwed on first and to compress the front plate down enough so that the rest of the nuts can be fitted. If you do need to change a tyre on a wheel fitted with a run-flat and you don't have these odd longer bolts, you will need to take the wheel to a place which has a large press, of a type suited to changing these tyres. Be aware that most truck tyre outlets apparently do not have the presses, though the ones that fit solid tyres to trucks (such as garbage trucks) may. My concern with permanently fitting the longer bolts, is that they will be exposed to damage and a risk to the public. They would not be permitted in Australia.
Caution: The removal (should you choose) of the Hutchinson run-flat insert if not done properly, can damage the tyre (or yourself). One method to remove it, is to partially compress with a ratchet strap, place the tyre under the fork of an engine removal stand and slowly pull it up and out. Another method is to start pulling it out and when part of it is out of the tyre under tension, cut it in half (risky). However the proper method is to compress the donut into a squashed oval shape using a ratchet strap and carefully remove it by hand (this is the theory, but does not always work in practice). There are web sites explaining how to properly remove a run-flat. The picture below, shows an example of a run-flat (looks like it has a bead-lock also).
First photo is of my tyre at 48 psi. Second photo is tyre with zero psi. You can see that it does not fully collapse.
My wheel set
The wheels I brought in, are for the MRAP (Mine Resistant Ambush Protected) vehicle (Hutchinson USA military two piece removable face rim; outer component model W0-1137 B 20X10 with inner component model WI-1137 F combined with the Michelin XZL 395/85R20 tyre). When fitted to my vehicle they measure as 2.5m from outside to outside (thats the limit here in Oz). They work out to be 50mm offset inside and 50mm offset outside, from previous. Local companies are now bringing in these wheels, so its easy to pick up a set without importing your own.
I will need to carefully regularly monitoring tyre temperatures from my type monitor as well as with an IR hand held sensor, after every major stop. By this means, one should be able to pick up any excessive wear problems in the wheels and possibly the hubs as soon as practical.
On 19th of August 2017 I collected the four wheels from the customs facilities by box trailer (see insert below). It was a heck of a job to unload and re-stack (took me most of the day and damaged my shoulder, which after a year to heal still is partially frozen). I never thought the wheels could weigh as much as they did (and these are small by comparison to some that Unimog owners fit). The wheels weigh more than 200kg each (about the same as the A380 plane wheel). I also found that I could only just roll one on a flat concrete surface, but when the wheel started to tilt sideways, there was no way of stopping it fall over or even to lift it up again by hand. These wheels could injure you badly if one toppled on you !!!
Pictures two and three below show what to expect on the front axles after removing a wheel after 30 years. I have removed the drum protecting the calipers in the third photo for inspection, ready for general a clean up, grease and repaint. They were all disgusting. I strongly recommend checking the ex ADF vehicles hubs carefully. This is because, the protector rims are a hassle to remove (so most people don't bother) but can hide a lot of problems, Note: I found that there are 6 grease nipples on each front hub.
After much work I eventually calculated and found the right brand and model wheel studs. A closely guarded secret at the time it seems, as I had to figure it out from scratch from dozens of brochures across dozens of companies across the word based on dimensions and standards. I purchased them from Germany: FEBI Bilstein 07940. They are grade 10.9, are 85mm long, M22x1.5. They are sold in sets of 20. You can also buy individual bolts on ebay (but an expensive way to go). There is likely a special tool available to gently press the wheel studs out, but I removed the studs (as shown on the fourth photo) by tapping them out with a lump hammer (rotate flange in order to remove each stud (as the stud may hit the calipers otherwise), but don't forget to screw a nut onto the thread (face flush with stud end) before whacking it out. I took a risk and did it without removing the flange from the disk, but apparently one is supposed to remove the flange from the vehicle in order to tap out the studs. I used a (25mm diameter centre hole) thrust bearing as a simple tool to pull in the new studs by tightening up a nut (it allows the nut to spin freely as it slowly pulls the stud in without applying much rotational moment to the stud). Unfortunately some rotational force does get transferred to the stud and the 5th photo shows how I use a Stilsens to grip the 'D' head bolt behind the flange to stop it rotating. Note: Very Important: The studs have a flat on one side ofthe head. The head must be rotated and aligned in the right spot before pulling in the stud. That's where the Stilsens comes in, it keeps the head in the right position as the stud is being pulled in. Of course, if you have a special hydraulic tool to pull the stud in, you wont have this risk of the head rotating, to worry about. Photo six shows the plastic wheel protector disk in position just before the wheel is fitted up to the hub.
Tyre pressure adjustments
Some higher end vehicles have in-cab tyre pressure adjustment on the go i.e. you do not need to stop or get out of the cab to increase or decrease the pressure of all the running tyres. There are two basic versions available:
- A retro-fit version which has exposed tubes on the outside of the vehicle and which can be easily ripped off on the first bush you pass and thus deflate the tyre,
- The integrated design where the air supply is connected through the centre of the hub, and has no external tubes exposed at the wheels.
Either way, both types of system suffer the disadvantage of air leaks (which can be a nightmare to resolve). From my analysis, the best value for money compromise is to permanently run air tubes with isolation valves and sockets up to each wheel location. You have to stop, get out, connect a short hose from each socket to each tyre. An option is to adjust the front pair separate from the rear pair. You can fit the control valve(s) in the cab and monitor the pressure, or if you prefer, do it from outside. By this means, all tyres are adjusted at the same time to the same value. Its not as fancy as some systems because you have to stop and get out of the cab, but its going to be much less prone to leakage problems.
I have decided not to install fast fill valves, nor to install air adjustment from the cab. As I am not likely to be in a hurry to adjust pressures, I'll do it the old fashioned way, and I have tubed up an air outlet socket next to each wheel position. By this means I only need to lug a short hose around.
UNIDAN have a RTIS kit for fast inflation and deflation if you don't want to make your own.
Note: In working out the optimum tyre pressures for your rig under differing conditions, a Michelin engineer recommended to weigh the front of the vehicle separate to the rear, then to contact Michelin and obtain their advice.
Spare Wheel(s) storage
I have noticed some examples where people have fixed their wheel support brackets direct to flimsy parts of the living module structure usually not designed for it. It is likely best to fix the wheel directly to the chassis, tray or barge board where possible. Placing your spare wheel on the bonnet is not a good idea for obvious reasons. Placing a large wheel on above the cab can be even more risky unless the support frame is robust enough to allow for emergency stops or vehicle crashes. You don't want your wheel ripping loose and becoming a missile (taking your roof rack with it) thus exasperating what might have otherwise been a possibly minor impact scenario. I was originally planning to place a spare wheel above the cab, but as they are so large and heavy, its not a good idea. Its also illegal here to put such a heavy weight on the cab roof rack (unless the engineer has signed off that the cab and rack can handle it in a crash).
If you are going to store anything above the cab, you may also likely want to consider fitting a small lightweight winch crane such as the Spitz
I hope to build a heavy frame across the rear of the vehicle which could be used to support one or two spare wheels side by side. A cable winch may be needed to be incorporated into the rear frame above/between each wheel. In order to raise/lower spare wheel. I have purchased a Spitz lightweight alloy crane for this purpose. The question also arises as to how to secure the wheel(s) to the rear support frame in a cost effective manner. One cost effective simple design choice is to use a stub axle hub, and/or stud adapter plate.
For MRAP Hutchinson rim wheels, below are some options I found, for purchasing this wheel package. Be advised that lead times can be long, depending where you buy them.
Buy locally new:
Up side: warranty provided, some peace of mind that you get what you paid for and they are new (maximum life).
Down Side: the price. This package may not leave you much change out of ~A$6k each (~$2k for tyre, ~$2k for run-flat, ~$2k for rim).
Buy locally slightly used or new old stock:
Up side: much cheaper than new and the tyres are often advertised as having most of their tread. They are brought into the country from usually either Europe or US. Good source of replacement tyres if the budget is tight or if you tend to chew them up often.
Down Side: usually used surplus military stock and life expired (according to military standards). The main risk is damaged or cracked crap tyres which don't last and may have been stored in the sun. Do your homework and only buy used tyres from reputable stable suppliers who have a top industry name.
Import yourself, (new old stock):
Up side: Unused (sold as second hand) US surplus but new, military stock.
Down Side: no warranty, no return and life expired according to military standards. Possible need to replenish heat retarding lube if you plan for them to function as intended.
Recently however, (May 2018) UNIDAN had been offering new (old stock) for very reasonable prices. This will save you all the hassles of importing your own and prices I found were as good as I could get direct from the States. I have to say, that these were a good deal.
Wheel Guards and Mudflaps
When using my rim/tyre combinations, they added 50mm to the outside from original. This meant I have to:
- Buy the wider replacement guards (from overseas), or
- Have a strip of metal inserted to make the guards wider, or
- Add a rubber fender extension
I went for the simpler option, and added 75mm rubber extension. I tried 50mm but it was not enough. On the matter of mud flaps, they also may have to be replaced. Make sure they are no less than 300mm from the ground. Note: If you add body lift, this means you will likely also need to replace the mud flaps. I installed dual wheel width mudflaps at the front to protect my air dewatering system and the steps from being covered in mud etc. Warning, when buying the rubber, make sure its not from end of roll, as it will arrive twisted and not fit for use. I discovered this the hard way.
Pneumatic seats can be adjusted for your weight especially as the vehicle has stiff military suspension (it was not meant to be comfortable).
I purchased a pair of new (old stock) Caterpillar 'Comfort Seats'. They are of a very solid construction (likely the most robust available?). They have breathable fabric reputedly designed for Australia's harsh outback conditions. The integrated seat belts option shown in the second photo have been removed and the existing cab seat belts are used instead (compliance with the original design). There are many good standard pneumatic truck seats available, I just happened to come across these.
If you are replacing the existing ADF seats with a modern style, you will highly likely need much stronger seat support boxes. The original seats, seat support boxs and frames are surprisingly flimsy (almost a joke in terms of robustness). My new seat support box's have been made to my design from thicker steel, fully welded (not pop riveted) and extra bolts to the floor pan. Something to watch, is your final seated height. It's all too easy in these vehicles for your head to be hitting the roof or your knees touching the steering wheel, if you install a seat which is too tall. My seats have a large dampening adjustment range (i.e. they can go up and down a lot more than average to accommodate big bumps in the road). But the down side is that they would not suit some people with meaty buttocks, they only just suit myself (being stick thin). Also, if the steering wheel is too low, there are extension bosses available to move the wheel higher up on the shaft. I fitted an approximately 140mm high extension boss for a Freightliner.
I also ran two by 4mm stainless cables per seat support box back to the curved rear of cab box section that the seat belt buckle end is bolted to. Note: there are 3 bolt holes behind each of the two seat positions (1 for the seat belt buckle attachment and 2 spare that I used for attaching the new seat support box cables).
The driver side floor pan is flat, but the passenger side needs shaping to the profile of the arched floor (fifth photo). I had both boxes made square and then cut out the passenger side to match the curved floor profile and then took it back to the local sheet metal shop for full welding.
Third photo is where I drilled the holes in the seat adapter boxes. I found that a magnetic drill is useful on this vehicle. It uses rotabroach bits; expensive, but worth every penny, as it can be very dangerous to try and drill large holes otherwise. I bought the cheaper rotabroach bits from China on ebay, as I don't need quality for a day in day out, factory use. I use the magnetic drill all over the vehicle, wherever its flat and made of steel.
Fourth photo shows fitment check for controls etc. Important also that you can adjust the seat and that your knees don't foul the steering wheel when using the clutch and brake.
I purchased a set of tank support brackets (along with matching 50mm widerubbers to suit) from Hilton Industries in Victoria, who make a wide range to select from.
It is not permitted to drill or weld the chassis (unless you know what you are doing). I used 12mm plate adaptor brackets (could have done it in 10mm) to pick up existing bolt positions on the chassis i.e. battery box and existing fuel tank bolts on the drivers side, and spare wheel and tool box bolts on the passenger side.
Like most of the key items, I purchased them years ahead of buying the actual vehicle. The fuel tanks for example, are mirror polished 316 stainless steel (200L each) and stainless steps from a Ford F650. These were custom made in the US. I chased up the serial numbers and then obtained the manufacturers drawings for the automotive engineer to scrutinise when the time comes. Unlike most fuel tanks, these have a low vertical height so as not to hang down too low and be wiped out on rocks etc quite so easily. They have the required 3 top connections each (vent, fuel OUT and fuel IN). The fuel tanks may need a protective cage around them one day?
I purchased 0-180/190 Ohm marine stainless steel senders. Primary tank (drivers side) is wired to existing fuel gauge, and the auxiliary tank (passenger side) can be wired to a new separate gauge or changeover switch. As there is no room for a new gauge, I added a changeover switch, so I can switch either tank to the existing gauge. Why fit another gauge when there is little room. In any case, you should always have a fair idea of how much fuel is in each tank at any time.
Fuel Selection panel and Water Filter :
Added fuel selector panel to select fuel from either tank. For the two tanks, I kept it simple and fitted two marine grade 3 way manual operated brass diverter valves. One is for fuel OUT the other is for fuel return. I will need to make sure both valves are turned towards the same tank when operating them. On my vehicle, the fuel line to the fuel filters is 7/16" (11mm). This is a difficult size to source compression fittings for, and I only found them from the states.
There are many products on the market all promising great things, so I decided I might as well go for a product from one of the big players. I fitted the MANN Preline 250/1 pre-filter with sensor, to remove water and to bring up a warning light on the dash if water is detected. I have not tested it yet, and hope it works as advertised. The filter has M15 ports. I am generally using 3/8"NPT compression fittings, so I had to find adaptors (the 2 adaptors cost almost as much as the entire filter). But if you are using M15 banjo fittings, then no need for adaptors. However, you then need to buy a special tool to push the tube onto a banjo barb.
Note: the inlet and outlet ports of the MANN Preline 250/1 pre-filter can be swapped over for different mountingorientations.
Another useful item for security and or emergencies and improved communications at remote locations, is a telescopic mast to mount things like: antennas, flood lights, etc. The better technology (but expensive) masts are usually slim, pneumatic and made from aluminium, and thus lighter. You can get cheaper models but they are often much thicker and much heavier for the same height. There are also electric masts which use a cable inside the mast to extend them. These can be prone to mechanical problems.
They are available from small to humongous in size. You can save money by buying a second hand mast. I managed to find a used military pneumatic Hilomast (11 meters) in the UK. It can lift 18kg of equipment (when new). I pulled it down, cleaned it and lubricated (using silicone oil). See photo of fully extended test where I fixed it to the side of the temporary workshop for testing. I have carried out a weight test and no problems lifting 12kg even though the Teflon seals are lightly scored. I recommend a locking model and I have converted mine to hand locking 'T' screw clamps so that I don't need special tools to lock each telescopic section in place when extended. I made my own locking handles out of SS, as genuine handles cost a bundle. Note: Without the locking option on a pneumatic mast, the mast will deflate (due to minor air leaks once the engine is turned off). If the mast does not have an internal cable option, one can use an external cable, either spiraled around the mast (see example on the white van) but a cage is needed at the top to contain the cable, or a curly cable down the side of the mast but a tube is needed down one side to contain it. A curly cable is expensive at A$400 just for the cable without the containment system (advantage is that they are less likely to get caught up on things).
Wind pressure, lightning strike and forgetting to lower the mast are SIGNIFICANT risks. If lightning hits directly, all bets are off, and you may end up with a very expensive melted mess. WARNING: An extended mast is a lightning attractor and its probably prudent to lower it well before storm activity mind you, the act of lowering it could also get you killed! I will likely fit an equipotential earth cable for use when the mast is raised as 'touch' potential can be lethal if you happen to be accessing the vehicle at the time lightning is around. Interlocking with engine start is recommended to prevent accidentally driving off with the mast extended. Most mast suppliers have options to fit a magnetic sensor switch to the base of the mast to detect when fully descended. Alternatively an industrial micro-switch can be used to carry out the detection in lieu (cheaper).
Pictures below show:
- the first fitment of my mast on the headboardfor measurement purposes, and
- example of Curly Cord vs Cord spiraled around a mast on another vehicle
Pole top Camera
If you like the idea of a top of pole camera, you will need to decide what you want it for, either general security (see who or what is out there in the dark within the immediate surrounds of about 50m from the comfort of the living module) or, for long distance scoping out of the surrounding countryside. PTZ cameras for each requirement are vastly different in style and costs. A good military PTZ camera with IR laser can pick out peoples faces at more than one kilometer away in the dark.
Electrical equipment connected to the mast may need surge protection. Surge diverters (eg MOV's) may be required at the top of the cable and at the lower end of the cable. Surge diverters should be line to line and line to ground. As the mast is unlikely to have a good electrical connection to the vehicle chassis, the cable might need a robust copper conductor (usually a braided shield). A subject matter expert will be needed here to provide an appropriate design.
The choice for TV antennas is extensive. Seems to me that a satellite dish style antenna is the only sensible option. They seem to average at 700 to 850mm diameter and usually the bigger the diameter the better the chance of reception. These domestic style dishes are not suited to pole top mount so I will need to allow space on the vehicle roof, but it will come at a price, using up valuable PV solar panel space. I have also come to the conclusion that I want automatic signal detection (who wants to muck about after arriving at a site searching for reception and having to keep adjusting things to maintain it). There are nice modern square array type antennas available now (the old fashioned round dish technology is likely on the way out).
A nice-to-have item are levelling legs for uneven locations. Trying to sleep with your head lower than your feet is unnatural and very uncomfortable. Equally uncomfortable is having your spouse rolling against you or vis versa if a shared bed.
Electo-hydraulic kits are probably the most common option, but very expensive (~$10k for supply only of a basic kit). The advantage of buying a kit is that all the bits are provided (you don't have to spend a lot of time designing, sourcing and integrating them). The disadvantage is that a kit may cost more, compared to buying loose parts and doing it yourself (but with the good chance of getting it wrong, and taking forever)? I've also looked at air, and air over hydraulic legs, but nothing so far seems suitable for the required weight load at least 3000kg each leg. The other risk is air leaks.
Generally, mechanical landing legs as used on prime mover trailers, now seem the more likely option at the moment. Mechanical landing legs can handle heavy loads, are available from dozens of suppliers, are reasonably affordable and are likely to be much safer than air or hydraulic systems as they cannot deflate and therefore, I suspect are safer when used for changing tyres and working underneath (unlike the alternative systems). Mechanical landing legs are normally hand winched but electric drives are available. Electric drives come in at about ~$5k for 4 kits plus a remote control (without the legs). Four legs are about $1k, so that's about $6k for materials. Still fairly expensive, considering what they are.
Some vehicles don't have sufficient underside clearance and may need a folding leg solution (this is likely to be expensive). If however, you have a robust beam extending out from the chassis both front and back and providing the overall width of the vehicle is still compliant, its probably easier to mount standard outriggers as used with vehicles sporting cranes. Most vehicles however, are going to require legs fitted directly on the chassis rails, but the problem here can often be that there is not enough extension reach. Folding legs are available as either fully automatic, or manual (where you need to crawl under the vehicle in the mud to flip them down. Risk is forgetting and driving off with them down, unless microswitches fitted to warn).
Other considerations can be;
whether each leg should be independently controllable (the risk is twisting the chassis if you have a standard vehicle and don't know what you are doing) or whether the front pair should act together and same with the rear pair or perhaps if the sides should act together?
Are controls required to be remote from inside the cab, or direct at the legs? Are they to be electric, pneumatic, hydraulic or manual?
At this point in time, I have not yet found a cost effective practical solution and there might not be any room them anyway.
I note that Bill Caid has designed and made a very nice set of practical stabiliser legs . Below photo is copyright, Bill Caid 1977-2020. All rights reserved.
If you want to simply raise the camper module from the tray (and even adjust the angle), rather than lift the whole truck, I have been referred to Rieco Titan who sell a kit (Electric Jacks - 4 Pack Model Number: 56211) comprising four electric lightweight jacks which are apparentlysufficient to lift the camper module up off the tray (when you want to be able to leave it at a camping site and drive off to town). Not a bad idea. I am not endorsing this product as I know nothing much about it. At US$2.5k plus shipping, its not cheap but if reliable and quality, probably worth it. Advantage with electric driven product is that it cannot deflate on you. For Unimog, they would need to swing out to clear the tray and would need extensions added to the legs. All easy to do.
Brush Deflection Cage
If you are planning to go off the tar (and that's what the vehicles are meant to be used for) where tree branches etc might be an issue, you should consider a steel cage around and over your vehicle. As you have likely invested a small fortune in your home away from home, the last thing you need is to wipe it out by a low hanging branch that the council forgot to trim from the side of the road. Also most of the bush tracks to far away places of interest are likely to have been worn through by standard sized 4x4s. They have cleared the tracks from debris to suit their vehicles and usually not for trucks. You should consider that you might be needing to do a lot of sawing etc to clear a path. Ideally, a deflection cage needs to start at the front of the vehicle and gently curve up to the maximum height so that on impacting an object such as a small tree branch, the object hopefully slides up and over the vehicle, or the vehicle deflects down and under it. Perhaps better to be jammed under a bridge than wiping off the top of your vehicle? If the cage frame is to start at the front of the vehicle, it must not obstruct the drivers forward view. The rules around this issue seem very vague from my enquiries and perhaps not fully understood by police or even some transport authorities? One officer told me that he uses the 50mm rule, i.e. if the structure in front of the windscreen is wider than 50mm its non compliant? I have not been able to find any rules pertaining to the maximum view width obstruction to date.
There are however strict rules about sharp edges. No sharp edges can be presented on the front of the vehicle. I seem to recall that the minimum radius is to be 5mm, but don't quote me on it.
Another decision is whether a bull bar needs to be frangible or not. Frangible implies that part of the forward structure will collapse and absorb part of the impact but as the old vehicles don't have air bags, probably not an issue. Non frangible implies a super rigid arrangement with the hope that small objects like cows and small cars will simply bounce off without doing too much damage? The down side is that serious structural damage to the chassis can occur with non frangible arrangements. In any case its important that bull bars etc are designed with rounded surfaces and no sharp projections which could cut a pedestrian on impact. Both a structural engineer and an automotive engineer might be needed here? For a frangible design, each section may need to be designed to be bolt replaceable if they get bent (why replace a whole bull bar if only one side gets bent). I am keeping my arrangement essentially stock, with just one horizontal bar added to provide some lower protection.
I was once lucky enough to travel the length of the Northern Territory (wet and dry seasons) during my term on the NT gas pipeline construction/commissioning. Wild camels and buffalo are commonly seen wandering the top end where there are few fences, though its mostly the buffalo that end up on the roads (camels are shy). Driving into these creatures at high speed is going to total even a large truck. I used to regularly come across bloated water buffalo bodies by the side of the roads (bulldozed off the road by the local councils) and left to explode in the sun for the birds and dingos to clean them up. You can smell the stench (depending on wind direction) often many kilometers before you get to the carcass. When working on this project, we lost more than a few 4x4's and some people ended up in hospital after driving into buffalos. I think one driver even died. Due to the great distances involved, nearly everyone drives fast, as you might have to travel 1000km or more in a day. I remember a close call when I was driving back from the Armadeus Basin gas fields to Alice Springs late one night looking forward to a beer (or two) at the motel after a very hot day (gets to 50+ C). I was doing at least 150km/hr at the time and only due to my long distance driving lights was I able to glimpse something vaguely ahead and stop in time. It turned out to be an otherwise mostly black cow standing in the middle of the road. Hence a strong bull bar and brush deflection grill is very likely a good investment for the front of the vehicle. On a related note (I digress easily), another near miss was when I was driving back to Alice one late afternoon and I saw some cars lying on their sides off to the side of the road. I slowed down, saw that there was a camp fire with Aboriginals seemingly calmly sitting around it, and as I slowed even further I only just in time noticed that there were two evenly spaced apart wheels on the road with rear axles still attached sticking upwards in the middle of my lane. I was able to throw the vehicle off the road, and get around them in time, and I hope the next driver behind me was as fortunate. When back in Alice, I asked around and heard that it was a common practice, that when a vehicle breaks down and they cannot fix it or it runs out of petrol, they know no one is going to risk stopping to give them a lift, and some in my case knew enough to remove the wheels with axles and put them on the road as a way to try and force vehicles to stop to persuade them to give them a lift back into town. Now it sounds callous that I did not stop, but in those days (early 80s) alcoholism and related violence was rife in the region,and some Aboriginal communities were absolutely decimated by it.
Always be on your guard when going into remote places. Always let someone know where you are headed and always have a back up plan for a fast exit from a site. Best to try to park your vehicle such that you can drive straight out quickly in an emergency. Its pretty rare for an incident needing an emergency exit, but most people I have talked to have had at least one experience such as a river rising rapidly or redneck noisy campers where they had to get away usually during the night. I remember driving over dry river beds at times in the Territory, and once on a sunny day (for weeks on end) with no clouds in sight and returning back the same way a few hours later only to encounter a raging unpassable flood (~2m deep). I would not have believed it if I had not observed it myself. Flash floods can be on top of you from not a drop in sight, to meters deep in an instant. This is usually because the flood water has traveled from many miles away upstream where a sudden heavy localised downpour has occurred.
Anyway, I'd better stop here, back to the issues at hand:
Pop top units may help with vehicle aerodynamics (having a lower profile), saving a (likely) small amount of fuel and allowing you to get under some of the minor country overpasses, but they are not much fun, as I see it. They mostly use canvas/plastic type side walls at the top which can (or will) eventually leak or let dust in and attract mould. Most unsettling I have observed, is the shower, often with the top portion a wrap around plastic sheet affair (lots of places for mould to grow and dirt to build up and lots more work to keep clean). The typical pop tops (it seems to me) are not very good for security resistance against the axe wielding drug crazed addict. I think I'll stick with a one piece secure structure if affordable. If you like your comforts (and we do), a proper toilet in a separate room with exhaust fan, hot shower (to get the joints working again), black water tank (or composting toilet), grey water tank and fresh water tank(s) are preferred.
I have however, observed split type cabins where the top shell sits over the bottom shell and often pneumatic rams are used to lift it up when parked. These provide the security but I am not sure how reliable they are in moving up and down, or for sealing to keep the bull dust out. In any case, I have only seen them on the US web sites. Check out Bill Caids site for information on one such module. I have not seen any here in Australia.
Living module Options
There are essentially four living module common options, as I see things:
- Slide-on (typically made for utes and very popular in the US),
- Custom built,
- Modified caravan, and
- Build your own.
I once built my own camper conversion into a small bus, on the basis that I wanted something better than the run of the mill commercial fit outs at the time. It turned out ok, but for resale, in the end, I discovered that one can never compete with the professionalism of commercial builds.
- Slide-on module
I have reviewed literally dozens and dozens of brands and models of slide-on camper units from the US and a couple from Australia. The US market is enormous with hundreds of slide-on versions to pick from and new models are coming out almost every week. The import option from the US is probably the cheaper route, (as the local companies here in Oz charge very high comparative prices simply because they have a captive market). It reminds me of the marine market, where prices seem to be jacked up simply because the product has something to do with 'marine' (the assumption is that if you can afford a boat you can afford to pay any price for parts)? Some risks of importing your own slide on module are costs of: freight, customs duties/taxes and conversion to Australian standards compliance for gas and electrics. Also warranty rectifications are likely to be a problem. If importing a new unit, before its been completed I would recommend trying to get the maker to cable up in accordance with Australian standards (600V insulation rating), because retrospectively replacing all the mains wiring could be next to impossible without having to rip off the panel linings. However, that's the theory, and when I contacted some of these US companies, they either refuse outright to wire to Australian standards or refer me to their Australian distributors. Hence, the actual opportunities to have one wired to our standards is going to be very slim to impossible (the markets are on the whole, cornered by the local Australian distributors). One option is to arrange for a local in the US to buy and send on to Oz via a container (if it will fit in a container). You will then have the issue of ripping out the US 120V wiring (probably not rated at 600V) and appliances and replacing them at great difficulty however, it just might be worth it?
The only thing I don't like about most of the US models, is that they seem to favour wood grain interiors which make them appear dingy and depressing (some would call it cosy?). Whereas in contrast, modern caravans here in Australia are nearly all going for bright white interiors making them appear open, clean, modern and spacious looking. If you are going to spend weeks or months in a small box, you don't want it to be dingy.
A useful US web site for information on hundreds of slider etc models is Truck Camper Magazine (https://www.truckcampermagazine.com/). I have not found any caravans or slide-ons with the lightweight engineering or quality comparable to the products available from the US and Canada. Australia is however just starting to catch up, with some using composite one piece panels etc.
- Purpose built module
These typically consist of a robust fibreglass module fitted out with standard caravaning equipment. They are the most expensive option I have discovered. Based on the local prices I was quoted, its an ideal option for oil sheiks or Russian oligarchs who can afford the very best and price is not an issue but for ordinary people like me, its not even close to an option. Advantages: Typically very good all rounder, with potential for large open living space and storage spaces. Purpose built product to cover all needs. Disadvantage: As there is a very small market here in Australia, they can be very expensive (can be a lot more than the truck) due to small production runs or more often, a bespoke or custom design.
- Modified Caravan
I will likely be going for the most time short option which is to purchase a robust off-road caravan with everything I need in it. I may buy a second hand unit if I can find one that suits? One method is to simply cut off the suspension and draw bar and directly mount the caravan chassis onto the vehicle tray with rubber isolation mounts. Alternatively, one can simply use the existing container mounts on the 4m tray. That way, the living module is a 'load' and effectively a slide-on slide-off (even if a forklift is needed). Probably best to use a caravan with a departure angle at the rear. The Lance 1475 is a suitable unit for fitment onto a Unimog U1700 but it has the door on the wrong side. Its not practical to get one shipped here as it will not fit in a container. Check out Bill Caids site for information on fitting a Lance caravan on a truck.
- Advantages: available with all the features you would expect, off the shelf.
- Disadvantages: A bit of engineering work to do, in order to integrate it properly so as to look tidy and professional, but likely worth the savings if you are a 'hands-on' type? I would be considering an external cage with this option.
After visiting many caravan shows, I have found only two local off-road quality products that will fit the length and width limitations with all the necessary comforts.
- Build your own
Seems to me that another option (if you have the time) is to start with a pre built enclosure (or make your own out of 29mm composite panels) and simply fit it out or start from scratch for those brave folk. You would need to likely be very experienced, if you want it to look like a professional rig. There is at least one company that now provides the components including wall panels, to assemble your own. A sensible option if you have the time to do it.
Shipping Container Option
Another option is convert a shipping container. As the ADF vehicle has the 4m container locking points already built in, its not a bad idea to consider the module a 'load'. That way, the living module does not necessarily need to comply with all of the usual rules. New lightweight (empty) containers are available for as low as A$5k. Smooth wall insulated shipping containers are available at reasonable prices. Some even use fully stainless steel frames with fiberglass panels. Weight here might be an issue (most are 3 tons empty?) but on the other hand, an external protective cage is unlikely to be needed as the inherent strength is in the container frame.
Cool Box option
These are the smooth wall insulated modules one sees typically fitted onto the back of refrigerated trucks of all sizes. They are no where near as robust as shipping containers (probably disintegrate at impact with the first small branch) but can be made to any size and spec. Probably the most sensible option if weight and price is a consideration (and it usually is), but often flimsy construction. I would be considering an external cage with this option also. They also have thick walls and waste a lot of internal space. I was recently quoted by a local company over A$26k for just the box (insane).
Fuels (for cooking, generator and space heater)
Here, gas is the most common fuel for cooking. There is however, an alternative option to lugging heavy gas bottles around and the inherent dangers of gas leaks; and that's diesel . There are appliances available such as: generator, oven, cooktop, room heater and water heater all of which can run from diesel fuel. They not likely to use much fuel either. You may find difficulty getting your gas bottles filled up, but you are not likely to run out of diesel. They are not cheap to buy and I have not yet carried out a life cycle cost analysis as to which is better in the long run. I saw these items demonstrated at a recent Sydney caravan show and was surprised that there was no smell (as the small amount of fumes are piped outside the vehicle). I think they are the only way to go, depending on ones budget.
Toilets (one of the more important topics)
I will try to deal with this topic in a polite manner. I don't have any first hand experience with motor home toilets but have compiled a summary of what I have observed and been advised over the years, from relatives with motorhomes/boats and from the internet. This is one of the more important issues to be decided (this and hot showers), especially when you are getting along in years like me. I like the idea of saving water (so I can have a shower regularly).
Seems to me, that there are essentially 5 main categories of motorhome toilets: Canister, Tank, Incineration, Bag-it and Composting. I still have no idea which is best, none are perfect, all have design or logistics issues. Here's what I have gleaned so far:
- Canister systems are simple, well understood, compact and there are many models to choose from
- Reasonably priced
- Can be flushed like your home toilet
- Can use toilet paper (so if you need much paper on occasion, this might be the solution for you)
- Spare containers can be provided to double or even triple capacity when out on the road
- The contents turn into stinky sewage and needs chemicals in order to break down the sludge into a more easily disposable liquid
- Have to lug a heavy container around. Some people carry a trolley around for this purpose. If you have issues lifting heavy weights, you might want to consider a black water tank system
- Very limited capacity. May only have capacity for one or two days for two people
- Risk of splashback when emptying. If at a dump-point, risk of encountering other peoples mess and having to deal with it all over the ground
- According to some, the stench can be overwhelming when emptying them in an indoor space
Black Water Tank:
- With a large tank, one can utilise a proper flushable toilet just like at home
- Can use toilet paper (so if you need much paper on occasion, this might also be the solution for you)
- Limited in capacity only by the size of your tank. A decent sized tank means that you have to stop less often to deal with it
- Black water tanks can only be emptied at special sewage dump-points which have the facilities to dispose of the contents
- You may have to deal with other peoples sewage left around the dump-point, some people are worse than pigs (no disrespect to pigs).
- You will likely need a separate large compartment to store stinky dirty (health risk) hoses. You will have to man handle the large hoses, with the risk of splash-back
- The contents of the tank turn into stinky sewage and you need chemicals in order to break down the sludge into a more easily disposable liquid
- Tanks need to be cleaned out regularly so crud does not build up and cause problems
- Internal level sensors are notorious for jamming or failing. Make sure that you have a level monitoring system that is not connected inside of the tank but rather, a sensor that is run up the outside of the tank
- Hoses can get blocked. I recommend watch RV: Runaway Vacation and the Robin Williams scene when emptying their black water tank
Typically they use electricity or even propane gas and mostly used for home based situations eg the Cinderella. Not sure if there is a domestic diesel version, but it would be a great idea (the perfect solution). There are military diesel toilets eg : Ecojohn, but they are not suited to a small motorhome. Incineration toilets usually require the use of a liner to contain liquids and solids until the incineration process is commenced.
- If diesel, then likely cost effective in its use
- Nothing much to empty but a bit of ash occasionally
- The most convenient of all toilet types
- If an electricity or propane model, its going to use up an enormous amount of fuel and not likely viable to operate in a mobile vehicle
- Very expensive to buy
Auto bag-it Toilet:
- Both #1 and #2 go into the same plastic bag
- Cost effective to buy toilet
- Automatically seals the bag once full
- Sealed bag is convenient to remove for disposal
- I suspect its going to stink (as the top of the bag is going to be open when in use)
- Special bags have to be purchased from the toiler supplier (possibly not biodegradable?)
- I have no idea how to legally dispose of the full bags. It cannot be legally placed in a garbage bin. If not a biodegradable bag, it cannot be disposed of in a dump-point or home flushable toilet (unless you open the bag and tip out the contents and then dispose of the bag separately).
Probably the best all round solution, I have discovered. I like both the 'Natures-Head' and the 'Air-Head' brands. Whilst they call them 'composting' toilets, its likely it would take months for the solids (#2) product to turn into harmless compost.
- The makers claim no smell (because liquids and solids are kept separate). I can believe that (having once been a sewage treatment plant engineer in my younger days)
- Main advantage, is that it needs no water
- No need for a black water tank
- As liquid is directed to the front of the bowl, it is collected in a separate container, and can be disposed of easily. If you already have a black water tank, liquids only can be directed to this tank
- Some people claim they can go 2 months without emptying the toilet (but they put their toilet paper in a separate container (bag), certainly not hygienic and certainly stinky as I have discovered from being on yachts where they sometimes practice the same methods). More likely it can last 1 week for #2 container and every day for #1 container for two people?
- The #2 in its dedicated container is not 'sewage' (because there is no liquid content) and is emptied into a plastic bag for disposal. I'm not sure if its legal to put a bag of #2 in a dumpster, but if using a biodegradable plastic bag, I see no reason why it cannot be dropped into a flushable toilet (hopefully not block it) or dump-point. If out in the bush, it can be buried (responsibly and away from camping locations).
- As liquids and solids need to be kept separate, one needs to make an extra effort to train yourself to always direct liquid to front of bowl
- Likely need to wipe the bowl out with wipes after use due to skid marks (no flushing water). Some people place paper mats (you can buy them made for this purpose) over the #2 area in the bowl, to minimise skid marks
- In order to empty the #2 canister, one has to lug the whole toilet through the camper, down the 1.5m ladder (and hope not to drop it on the way). Seems to me, that it would be more sensible to fit a hatch in the rear of the shower/toilet cubicle, so as to be able to slide out the whole toilet and deal with it OUTSIDE the camper, rather than inside the camper.
- As above, one needs to get up close and personal with your #2's
- Need to carry spagnum moss or coconut husk to place in the #2 canister which mixs with the #2 to dewater and dry it out
To be plain about it: If your bowels function well, you don't have irritable bowel problems, you don't suffer from gastric diarrhea a lot and you have firm stools, then this is the likely choice. If however, you need to use lots of toilet paper, then its not likely for you.
Some things to pack, (which seem important to me)
- Chain saw (I consider petrol is best, even though I hate the idea of carrying petrol around),
- Bow saw with spare blades,
- Safety reflective vest, eye and ear protection (PPE),
- Three reflective triangles (for kerbside breakdowns),
- Wet weather breakdown gear (reflective fluorescent jacket with hood and trousers),
- Tools to suit vehicle including 3/4" torque wrench with socket range including for wheel nuts,
- Robust jack and lumps of hardwood,
- Selected spare parts such as engine belts, oil and air filters,
- A wide range of the common size bolts, nuts, washers etc,
- Recovery equipment,
- Outdoor enclosed fire place such as the Ozpig,
- Recovery boards. I am planning so save some money by using plastic freight pallets. They are likely to be much more robust than the typical 4x4 products I see on the market and cheap as chips (used ones often free). I hope to report back one day as to how they perform.
- Shovel, pick, axe, etc,
- Satellite emergency beacon,
- First Aid kit (and learn first aid),
- Spare set of spectacles (if you wear them),
- Broad brimmed hats and head fly nets,
- Large packs of selected cable ties, insulation tapes including self amalgamating tapes,
- Inverter power generator(s) ultra quiet,
- Heatshrink kits,
- Pneumatic tubes and fittings,
- 12/24Vdc soldering iron and solder.
- Wire, crimp fittings, crimp tools and fuses.
Air Conditioning Considerations
When working in the Territory, central Queensland and the gulf, I found (surprise surprise) that 50 degrees C (plus) in the shade with 100% humidity is very uncomfortable and so are below zero (eg: -5C) nights. I don't know too much about air conditioning options available for vehicles yet (still doing my homework), but there are two basic requirements for air conditioning. See write up on Page 2 detailing the equipment I purchased for the cabin.
- when you are camping (engine not going) , and
- when you are driving (engine going) for the cab.
A living module air conditioner draws a lot of power eg: 3kW, so a very robust power source is needed. Batteries are unlikely to cut it, even with lithium, calcium or other battery technologies, especially if relying on solar PV panels.
Typically an air conditioning compressor is fitted in the engine compartment and usually driven from a rubber belt and occasionally even direct drive and sometimes an electric motor. As most vehicles will already have a heater (from the engine hot water), a reverse cycle air conditioning system may not be required for the cab, so I have gone for cooling only. I have purchased a heavy duty belt driven Sanden compressor, a Red Dot evaporator for the cab and a Red Dot roof condenser (as its the only compact unit I could find that does not foul the roof hatch). It only just fits with millimeters to spare. Note: The R6160024P unit does not include all the innards (only the fan and radiator), you will need to order the other parts such as drier and trinary pressure switch (I'm putting them under the condenser casing rather than under the bonnet as I like a tidy design). Refer to page 2 for details.
Vehicle Engine is not running at the camp site
Here it gets tricky. There are two sub-scenarios here i.e., when connected to the grid (as in, at the caravan park) or when away from the grid.
The living module air conditioning condenser can be fitted at various locations; on the roof, underneath the vehicle, wall mounted etc. Some prime mover sleeper cab systems can for example appear to tick all the boxes (diesel fuel driven, auto self start/stop to top up batteries, reverse cycle air conditioning), but they don't have the capacity for a larger living module in 50C conditions. Seems that most caravan air conditioners are typically located on the roof (good spot to be easily torn off on the first low bridge or tree branch). They are also going to take up valuable solar panel real estate.
After doing some homework, I have found that the purpose designed RV air conditioners are nice but very expensive. Low sound level is very important so as not to disturb the ambiance or adjacent campers. Inverter technology air conditioner of about 2kVA should do the job. The inverter technology will allow low startup current. If you pick the right model, it can be very quiet.
Another option is to simply use a common house AC system if you can find room to mount it !! The pros for a house system are: cheap, parts are easily available and the big names have a large dealer base across the country, quiet, powerful, can be run from diesel/petrol generator. The cons are: vehicle vibration could damage the compressor pump but it's possibly worth the risk of having to have it repaired a few times, warranty will likely be voided, need an inverter if running from batteries. They will also look ugly and take up a lot of room.
A powered camping site connected to the grid is the most efficient usage of energy.
When away from the power grid you will likely need to use a generator; LPG, petrol or diesel. I don't like the idea of lugging petrol or gas around. Gas is consumed at a very high rate and petrol gets stale and gluggy after a while. One needs to run a petrol generator regularly to keep it maintained otherwise it can gum up.Gas generators are rare in Australia but common in Canada/US. Trying to find someone in Australia to service a gas generator recently, was impossible.
A diesel generator on the other hand is likely going to be safer (due to the potential reduction in explosion risk), last longer, need less maintenance and can be run direct from the vehicles fuel tanks. Inverter generators are strongly recommended as they can provide proper sine wave output to suit electronic equipment, self adjust speed to suit load and are more efficient (less fuel used) and probably quieter. Diesel generators are about twice the price of petrol equivalents. Its a rip off of course, as there is no good reason they should be so pricy. There is certainly a large enough market base for them (the demand is there, but the suppliers are just not listening).
The air conditioner start-up current needs to be factored in when selecting the generator. Generators usually have a quoted average running power level and a peak level (which is only for a short duration). Be aware that the peak level is sometimes quoted. If you don't select the right size generator, the air conditioner might never be able to start. Also keep in mind that when running in a hot weather environment the actual available power will be reduced.
In terms of noise there are two sources, the motor mechanical noise and the exhaust noise. SFAIRP you cannot do too much about the mechanical noise as the motor needs cooling air flow other than ensuring that it is a fully enclosed model. For the exhaust, one can fit a secondary muffler and plumb the exhaust up the side of the vehicle to the roof.
Its very important to keep noise to a very low level. Besides being a light sleeper, I do not want to annoy other campers either. I certainly would not be buying a tradies open cage generator as the noise levels are usually severe. Ideally one should be looking for a fully enclosed generator with dBA in the mid 50s. As Honda (EU range) and Yamaha have large distribution dealer networks across the globe, parts and repair shops should be easily available. To give you some idea, a low level conversation is probably about 40dBA. Some other companies quote similar ratings but I don't necessarily trust their specs.
I am aware of Redback generators which also quote low sound levels. RB4 model quotes Ultra-quiet 49dB - 56dB. Very good price and has remote control. I'll be checking this one out.
Unfortunately, fully enclosed diesel generators in a small package eg: 2 to 5kVA are very rare. So far, I have not been able to source any quiet diesel generators in small sizes. I cannot fathom why none of the big players are making quiet diesel models? In the end, I suspect I am going to have little choice other than to buy a pair of Honda EU30is for example (and run them in parallel) and lug around petrol (which I hate the idea of) hoping it has not gone off when I need it. Just another thing to manage !!
Safety camera systems
You might consider:
- a forward view on both sides for side clearances when creeping past tree branches etc at low speed,
- a top forward view to check height when passing under low bridges etc so you don't rip off the roof or the PV panels, and
- a rearward looking system.
If you are planning on climbing over some obstacles, an underside clearance camera might be useful?
If you want to be a courteous driver, you could consider a dual camera at the rear with independent long and short focus. The long focus allows one to keep an eye on road trains barreling up behind you at 150km/hr so to that you can let them know when you will be pulling over to let them pass (they will expect/insist that you get off the tar onto the dirt to let them pass). Ideally this long range camera should be turned on all the time, and the short range pointed downwards for when you are reversing.
There are lots of mobile DVR systems available for commercial vehicle fleet management systems. I call it a 'black box' as it provides local recording facilities and, can be set up to automatically send the video off to a remote location server (via Mobile Network) for later retrieval by authorities etc. Ideally all views should be recorded for legalistic purposes and able to be viewed over the internet on a mobile phone or desktop PC. I installed a RECODA model M620 for this task. With most DVRs, you can assign various input triggers, shock, or open door, or engine fault, or an emergency button, turn indicators, brakes,reversing light etc to set recording going (or running on a continuous loop all the time).
GPS and 3G/4G are often options along with a website PC application which shows your current location and (supposedly) in real-time, access to the video on-line. Unfortunately, the (black box recorder) system I am presently testing, requires internet access via the manufacturers Chinese server. I would not have purchased it had I realised that. Because the video information has to go part way around the world and be processed by their server, the supposed real-time video speed varies considerably. Its never 'real-time' due to the limits on bandwidth. But the Google Maps position display seems ok. If the base station PC has the monitoring software and internet access, they can view the cameras video, check vehicle speed and position anywhere in the world where GPS is adequate. Good to track the vehicle should it be stolen. Its designed for fleet management, not really for an expedition vehicle. I ordered a model with dual channel (backup) memory recording facility and a quad display monitor in the cab so the driver gets a good view of what's going on around the vehicle (which is the main purpose of it) when maneuvering.
Display Monitor & Cameras
Cameras need to be good quality (with metal case) if possible, HD (I went for 2 M pixel) and sealed to at least IP68 where possible. I have gone for both side cameras, rear camera and front roof camera. The whole system needs to be vibration proof and suited (depending where you live) eg -5C to +70C. You can connect your cameras to a DVR or direct to the monitor without DVR. Make sure you go for the aviation 4 pin camera connectors, as these are water resistant. Anything else is asking for problems. The cameras nearly always only have a short tail cable (about 400mm) and you will need to order an extension cable. I bought 10m extension cables, but when I ran them via the engine compartment (so that the cab can be tilted) they are a little short. They do reach each quadrant of the rear tray of the truck, but at tray level. So I will need to buy some 2m extensions to take them up to the top of the cab height. Even with the water resistant aviation connectors, the threads can corrode and water gets in, so its a good idea to wrap each joint in 3M self amalgamating electrical tape to seal up the connection.
General warning, if buy the parts separately, you may find issues with pin outs of connectors. Whilst nearly all manufacturers comply with a generic standard and most systems are plug and play, some are not. If you plug in the camera and it does not work, it may be because the manufacturer chose to have power and video pins differently to the norm. Can be safer to buy the whole kit, so you have some confidence that it should all plug together ok. I bought my parts from the manufacturers direct in China, but I am paying the price, because one video input is not working, possibly because the pin-outs are not normative. Yet to resolve the problem because the language barrier makes it difficult for the Chinese technicians to understand the issue and they are not really interested in my problem unless I were to buy 10,000 units.
CMOS cameras are the most common, cheaper and use less power. If however, a camera needs to be on all the time eg: truck reverse view, the CMOS type of camera may not last very long, a better camera is the CCD technology (better quality crisper picture and it will last longer). So, for close up reversing views etc, CMOS is fine, for the long range rear view go for CCD.
The two most common car monitor sizes are 7" and 9". I suggest go for the 9", as when the screen is split into 2 or 4 views, they are small. My arrangement has 2 inputs (AV1 and AV2). AV1 is the quad display from the DVR, and AV2 is a full screen display from the reversing camera (triggered by the reversing light or by push button). Some models have 4 camera inputs. These car monitors have subtle variances in shape of push buttons and options etc, and prices are all over the place, but they nearly all come from the same factory in China with the same technology and same quality (just packaged up differently so on-sellers can charge different prices). I have found the same monitor from A$50 odd to A$500 odd. Note: Too many displays and cameras can become counterproductive and a driving distraction hazard.
I suspect that for most people, a 2 channel system is all that is needed, eg two rear views, a close up for when reversing and coupling up, and along range (on all the time). There are two-in-one camera units available for this. One camera can be tilted down to the coupling area, and the other camera can be tilted up for the long range rearward view.
There are also 'birds eye view' systems where you can see all around your vehicle at the same time just as if someone was hovering above and filming everything going on around you. This involves a separate set of 4 cameras which all look down.
I once saw someone who was standing behind a parked 4x4 in a car park, and who was struck and injured because the vehicle driver did not see the victim nor did the victim hear the vehicles modern (quiet) engine start up. The victim got away with minimal injuries, luckily. I have now fitted a reversing camera and loud truck reversing beeper (negative issue is that it annoys the neighbours) to my Land Rover. It has done me well, as children and adults ignorantly often walk past the back of the vehicle whilst I am reversing. I have done the same with the truck but this time have purchased a truck white noise (quacker) version which is less annoying to neighbors. Or if you want to do a simpler quiter version, there is a replacement generic light bulb (for reversing light) which you can buy which has a noise maker built into it (but not as loud as a proper unit).
Emergency Strobe or Beacon Lights
LED orange strobe warning lights can be a useful safety item when coming across an accident or having broken down yourself. They are typically used as a light bar on the roof of emergency trucks including tow vehicles. The best brands are usually those used by the government agencies (but are very expensive). Go and have a look at your local cop shop highway patrol car to obtain the manufactures and models. Its a choice between very expensive and good longevity (and high availability), compared to cheap and likely short longevity. By buying a lot of separate cheaper lights, you can possibly improve the overall availability to something like the high quality units. I have found that the cheaper LED light units I purchased from China don't last many years.
Its illegal to use any colour other than orange here in Australia and to never drive with them running. In fact only certain vehicles can operate them at all. Basically, it is illegal for a private individual (such as myself) to ever turn one on. However, the NSW Vehicle Standards Information sheet publication 10.366 dated 24 Nov 2010 advises: ' The light does not have to be removed when the vehicle operates in non-hazardous situations but it must not flash.' it also states that 'Examples of vehicles which can be fitted ... are: Volunteer vehicles not accredited by the State Rescue Board.' Make of these what you can. But I would rather have a light fitted just in case its needed in an emergency, and pay a fine if I have to.
If you do intend to fit one, best to have an indicator switch in the cab, so you don't miss leaving them on whilst driving (I've done that a few times without realising after emergency callouts). Check your local state laws about their usage.
I am installing a wireless 18 channel remote control system. The idea is to be able to operate various systems from a wireless pocket remote from up to 100m away. Not sure how successful it will be, bit of a toy but might be useful to gain attentionif trapped inside the camper module.
Even with a militarized commercial engine and transmission, its still a very good idea to monitor the various critical systems. There are many add-on engine management systems available on the market. They seem either cheap and dodgy or laboratory quality and very expensive (overkill). The only useful ones I found are for twin engined aircraft or ships. Apparently no one makes a middle of the road fully configurable multi input system for trucks?
The higher temperature transducers are either thermocouple or RTD type. As we do not need precise accuracy (a couple of degrees either way should be fine), a thermocouple is fine. The most common and cost effective thermocouple is the K type as it covers a very wide range typically -300 to 1250C (hence it will do everything). Note that if you are extending the cable (as it forms part of the thermocouple), you must use compensating lead. To use copper can cause inaccuracies. Even the jointing of the wires would normally be done using compensating terminals, though I have found that its not needed for our accuracies.
Lower temperatures are often done with negative coefficient thermistors (oil, water etc).
I consider the following functions important to check:
- engine oil temperature,
- gearbox oil temperature,
- differentials oil temperatures (manually using thermal gun),
- hubs oil temperatures (manually using thermal gun),
- exhaust gas temperature,
- engine water jacket temperature,
- engine oil pressure,
- air inlet manifold pressure #,
- Tyres pressure,
- Tyres temperature.
Most engines (in general) are de-tuned by the vehicle manufacturer to make them semi idiot proof. If for example you bypass the turbo safety limits, you should fit EGT and turbo pressure monitoring to help ensure that you don't exceed the manufacturers general design limits.
# Turbo manifold pressure is normally implemented via an analogue meter as this parameter is quite dynamic and difficult for human interpretation using a digital meter. Temperature monitoring of hubs and differentials could help to detect a failing bearing before catastrophic failure. However, presently I just use my hand or the IR meter to compare temperatures. If they are all the same, then probably no issues (expect the front to be fractionally warmer than the rear, as the front do most of the braking effort). Investing in a contactless infrared meter is the more sensible way to go, as by this means you can check all of the drive train components at regular cycles and write the values down in a log book. If you see one going up over time, it might mean a problem that needs looking at? Catastrophic failure of a bearing is not something you want to happen, anywhere, especially with a large non standard vehicle, so I cannot strongly recommend enough, the importance of regularly checking non monitored drive train component temperatures after every long run.
I used the MadMan EMS-2 monitor. To date, I have connected the following parameters (because they were easy):
- Engine oil
- Gearbox oil
- Coolant level
I have fitted a standard 1/8 NPT VDO temperature sendor to the gearbox via the forward drain hole using an adapter. The EMS-2 has a standard calibration curve for a standard VDO sendor, so thats easy to set up. Best to get the same model sender that MadMan nominate, otherwise you will have to program the temperature vs Resistance curve for another type of sensor.
Engine oil access was a bit trickier. I accessed engine oil temperature from one of the oil filters M10x1mm drain plug (because its easy access). I will likely take engine oil pressure from the other oil filter drain plug one day? I used the VW coolant sensor (LT 027919501) as its the only short barrel M10x1mm thermistor sensor I could find easily available (used in dozens of different vehicles). Because its so fragile, I used copper washers with 'O' rings built into them to seal against the filter canister. My previous attempt to tighten one up using just copper washer, ended up in shearing off the brass sensor. Luckily an 'easy-out' was able to remove the thread left in the filter canister. The EMS-2 needs to be programmed for this sensor curve. After much work, I eventually found the right curve (there are hundreds of different curves). I programmed in 6 points across the curve (should be enough). Today the temperature ranged from 10 to 18C, and the display was within a few degrees of actual, so I know its ok at the low end. If I find its not too accurate at the higher temps, I can adjust the calibration by comparing temp with the IR heat gun and measuring resistance. Of course, the best way is to use a water bath and do your own curve before you fit the sensor (I'm lazy and did not bother).
Note: Its important to run a negative wire to each of the sensors, as the casings earth returns might not be solid. The gear box for example might not be sufficiently well earthed and this may cause intermittent results. The below photo shows a method of earthing the oil temperature sensor. Its a ring lug and a few copper washers to ensure that the earth is available for the sensor return path. You will need to run one wire for the senor and one wire for the earth.
After a couple of years searching the internet for a practical, compact, reasonably priced multi input, reliable monitoring/alarm system, the most suitable product I have found, is the USA made 'Auber'. Its very small and I have had one on test with EGT for about 6 years now in my Land Rover (which has very stiff suspension and truck rated tyres) and no issues found with vibration, accuracy or reliability. At ambient, mine is only a degree or two out, but that's dependent on the quality of the transducer probe (usually K-type thermocouple). Auber also sell a dual channel version (see photo). This particular model has a kit for EGT and boost pressure. I selected two different colours so I could easily distinguish the two displays without having to think about it too much. Whilst boost should normally be an analogue meter due to the usually fast changing dynamic, in this case the turbo is not vary fast to spool up, so digital should be ok? I guess I'll find out.
Note: I don't see the need to pick up the turbo temperature at the turbo inlet side as some would believe, because eventually the whole thing equalises in temperature, and we are not running up near the limits. In my case I tapped the insertion probe holder into the turbo exhaust casting . Pro is that I did not need to drill the turbo casing nor the exhaust manifold.
This module requires a bit of programming. There is a 'Quick Guide' on their web site, it makes things easier. Note: I had the thermocouple wires reversed, and when I saw the temperature going negative, I knew what I had done. Temperature programming is easy, but Pressure is a bit tricky, as you may need to zero out for the local air pressure where you are based. Pressure sensor needs 5Vdc (from the display unit) and has an output of 0.5Vdc at 1 atmosphere (engine not running). My sensor has correct output at 1 atmosphere, but little increase when the engine is running (at no load), so I don't yet know whether is going to be ok on the road yet. Note: You will highly likely need to connect the terminal(8) for dimming (can also be done manually from the front panel) to the headlight circuit (otherwise its blindingly bright at night, as I recently discovered).
Oils need to be maintained within a strict temperature range. The combustion process produces water and the intake air of course has water vapor in it. This finds its way past the piston rings into the crank case oil and causes corrosion of bearings etc. In order to avoid the problem of water (condensation) oil needs to be above 100C (to drive off the water) but not too hot so as to break down early. According to blurbs on the internet, the ideal range is between 110C and 126C. Its a very tight range to try and manage, so make of this what you will. In fact the only real control over oil temperatures (unless you go high tech) is your driving manner and simple monitoring systems will enable you to maximise the longevity of your investment by driving appropriately.
Radiators and heat transfer
In the design, if you plan to tweak the power plant, you might need to consider and allow room for a variety of additional retrofit radiators, such as:
- engine oil
- gearbox oil
- turbo intercooler
I came across an incredible example of a complete rebuild on the internet recently where they have fitted a bank of radiators across the entire front. However, by transferring heat from fluids to the air, the additional hot air needs then to be removed from the engine compartment and there is a risk that the lifespan of plastic/rubber engine components (due to potential elevated temperatures?) might be reduced as a result of restricted air flow? Typically air flow improvements are achieved by means of electric fans and extra vents. After tweaking (over fueling) my Land Rover over many years of trial end error adjustments, I found that the heat buildup in the engine bay had increased considerably. I saw what the US military do to their vehicles which patrol the Mexican border and I copied it (well at least my version of it) by placing a row of vents across the top of the bonnet. The safety risk by adding vent grills to the bonnet however, is that a pressurised oil leak may cause oil to spray up and out of the vents onto the windscreen restricting the view. Its a risk one needs to consider.
I thought it a good idea to replace old incandescent bulbs in my dash with LED versions (better longevity, less current, brighter, pure colour spectrum). It was a mistake.
Just tried the dash instrument lights at night. They are all fine for daylight viewing, but at night the cab is lit up like a Christmas tree, affecting my night forward vision. The only dash lamps now remaining LED, are the gate indicator lamps (green). I need the brightness so I can clearly see them on the brightest day. Relay 17 is meant to tone them down at night by means of an inbuilt resistor, which is suited to dim the incandescent version lamp. LED lights are not very good at being able to be dimmed and the resistor value is not sufficient to dim the LED light. I have removed relay 17, and hardwired a new relay to switch in a custom resistor (value yet to be determined) to dim the LEDs appropriately at night.
I noticed that the existing incandescent bulbs in the instrument clusters seem very dull, I can hardly see them. Not sure yet why? Maybe I need to give my eyes time to adjust?
First off, I fitted a Heavy Duty Rhino wireless 24v central locking (via motors) and alarm/immobiliser. The Rhino system has the usual rolling code technology etc.
A definition for the purpose of this section:
- Latch/unlatch: To release the door so that it can be opened by hand with a key from the outside.
- Lock/unlock: An additional level of locking that would prevent anyone opening a door irrespective of having a key on the outside. This is achieved by sliding the red lever on the door up and down by hand when inside the cabin. Probably to stop an attacker simply opening the door on you, because the stock outside door handles have no locking ability (no key lock).
There appears no way to make the mechanism able to be locked/unlocked by means of a vertical pull rod to a motor actuator However, i.f you do want to latch/unlatch the door latches via central locking motors, a rod connection point needs to be welded to each of the existing mechanisms. See photos below. First attempt was at 90 degrees and was wrong as it pressed against the window guide. Had to cut off and re-weld it parallel. Now all installed ok. But here's what I found:
- The door latches are not suited to being motor latched/unlatched, as they are too stiff. With my latching mechanisms, I need two hands to unlock/lock the passenger side but can do the driver side with one hand. I've no idea why. In any case, a motor can intermittently operate the driver side but no way it has enough power to do the stiff passenger side mechanism.
Note: The new Febi modern replacement key lockable door handles need the key to open the door. It is not possible to lock/unlock a door and simply push the button to open a door, the key always has to be used. Now it may be, that a version of the handle exists which can be operated without a key when needed, but I never found one. In retrospect, it was not a good idea to add central latching, here's why:
- The latch mechanism does not release the door but simply provides an additional level of locking. As I still have to use a key on the outside to lock/unlock the door, it was a pointless exercise to install central latching. I have disconnected the pull rods but left the actuators in place. They make a satisfactory thud every time I remotely alarm/un-alarm the vehicle, but that's now their only purpose. If anyone finds a way to convert the mechanisms to be able to be actuallylocked/unlocked, let me know.
A solid state digital tyre monitoring system is a must. In-cab centralised tyre pressure/temp monitoring systems are now cheap and easy to install and two options are available: sensor is inside the tyre or the sensor is on the outside of the tyre (screwed onto tyre valve). They are an invaluable product for warning of tyre pressure problems and over temperatures. Also, its highly unlikely that you will be able to obtain a replacement tyre of the right match and quality off the shelf, and especially in the middle of nowhere. Its worth also monitoring the spare wheel(s) to ensure they have not gone down over time. Reminds me that one day I had better check my spare on the Landrover, after not looking at it under its cover for about 15 years. I know its got some air in it, as I give it a whack ever so often to see if its soft. Still hard. Goes to show you that flat tyres are almost a thing of the past, at least on tar roads.
Here's my assessment:
1) Inside tyre sensors
- Protected from damage.
- Normal flow rate when adjusting pressures.
Sealed (battery normally not replaceable) and item need to be replaced when the sealed battery expires. This means removing the tyre (very big job in my case). However, if this is every 5 years, it might be a viable option?. However, as my wheels have military run-flat inserts, this limits me to the external types of sensors, as detailed further below. Probably not suited to wheels with bead-lock inserts either.
2) External to tyre sensors
In-line version and end of cap version.
Advantages: Cheaper than inside sensors. Battery usually replaceable and easily replaceable, but generally needs to be replaced every year. In-line version does not need to be removed to adjust air.
Disadvantages: If you have rubber valve stems you should probably change them to metal, as rubber can allow the sensor to flop around potentially causing damage to the sensor and a leak. Capped version needs to be unscrewed to adjust air pressure, are assigned to a specific tyre and can be mixed up. It may take the monitor a while to display the pressure after the sensor has been disturbed. Someone can steal it easily or it falls off (and with the in-line version, your tyre goes flat) In-line version is exposed compared to the capped version (as it sticks out a lot more), and can restrict air flow.
Other options to consider:
- absolute pressure measurement (safer and easier to use), or
- calibrate yourself (risky and a hassle),
- real time monitoring (picks up problems asap),
- low battery alarm. Systems that don't monitor their own battery voltage wait until they are no longer receiving input from a tyre sensor for a period of time before warning of a problem. I have read of one product that takes 45 minutes. This is a worry as you might have no monitoring for that period.
Future needs. Do you want to fit your spare wheel(s) with sensors and also allow for anything being towed? If intermittent towing, perhaps best to carry some spare external sensors so they can be quickly screwed to any as-hoc trailer or caravan you decide to tow. A commercial system for large trucks is likely to be the best as should be designed to provide a good signal strength and they often have options to add additional wheel sensors.
I ended up buying the B-Qtech 6 wheel sensor set (from Amazon US). I fitted the four wheels, one on the spare wheel (and one as a spare). I checked the temperatures displayed for each tyre with my infrared gun and they were within 0.5C, that will do me. Pressures are sufficiently accurate for me also. For a while it was in permanent alarm mode and I could not figure it out. I thought it was defective, but I eventually condescended to reading the (poor) instructions and eventually figured out that one needs to enter the actual tyre pressure (as displayed) for each tyre in the alarm settings. Once I matched them up, the alarm stopped. Seems to be working ok. It will be a hassle to have to re adjust the alarm setting whenever I change tyre pressures, buts thats life. I also purchased a set of de-flator screw on valves. I have pre-set them to 20psi for the moment. That all work ok, and save time by not having to hold in the valve by hand.
Fast-flow/fill valves could also be useful also, especially if you need to fill a flat tyre in order to re-seat it or if you are often adjusting tyre pressures (but you would need a veryyyy big reservoir added to be able to take advantage of these valves).
Wider Access Steps
I chopped up some stainless fuel tank plank steps, tack welded end stops and took them to the professionals at Beauchamp Metals for welding. I also welded Unistrut rail onto the existing two steel steps so that the stainless steel planks could be screw mounted on top of them. A motorised 3rd step would be the most sensible option here, but the only viable fold down step is long out of production in the US and no one makes anything suitable for a truck (I mean a real truck not a pickup). The next best thing is a cable step, as it will flex on encountering an object. The real deal are expensive and not easily available in Australia, so I have made my own using conveyor belt rubber to hang from the existing lower step. This lower 3rd step arrangement (whilst flexible) is far from ideal however, because its likely that when crawling over a boulder or such, the first thing to touch after the wheel rolls over, will be the lower step and mudguard. As I have had to fix the mudflap to the lower step (in order to pull the rubber flap away from rubbing on the tyre at full lock), and the arrangement is now too stiff, and likely to be wrecked on the first obstacle I crawl over. That's why the only viable solution is a motorised fold down/retractable step, if such existed off-the-shelf for this application.
The above picture shows the three steps. The lower one being the flexible hanging step. I'm not happy with it, as its probably too stiff now. I will remove the lower steps, and redesign. I also think that 20mm (2 layers) of rubber hanger is too thick. I re-made the lower stepsusing a single 10mm sheet as per below, and its still quite sturdy.
The ex ADF platforms here in Oz come with the traditional camouflage paint scheme to suit the Australian bush environment. There are lots of web sites providing information on colour codes for those who want to match up correctly. The paints used (at least in Australia) are made to special formulas in order to reflect Infra Red light. The paint is Protec 601 series Camouflage Enamel to APS-0165/1 (if you can get it?). Protec advise that their 342 series is the standard domestic automotive formula and there are no restrictions on buying it. However, if you want the proper military paint with all the high quality materials, its the 601 series, and almost impossible to purchase without a military purchase order. On the down side, in a breakdown scenario in the middle of nowhere, its probably not a good idea to have a vehicle which is difficult for the rescue services to find using infrared.
The following are the Protec domestic codes (not infrared light reflecting):
- 342-5726 - Camouflage light Tan
- 342-5265 - Camouflage tan (brown in actuality)
- 342-1166 - Camouflage Green (likely the old Olive Drab?)
- 342-7165 - Camouflage Black.
Dark colours can cause heat problems. The outside of a dark vehicle absorbs sun heat easily and re-radiates it back into the vehicle compartment's. Matt paint on the bonnet however is a good idea from the viewpoint that it will reduce unwanted light glare from the bonnet whilst driving at night.
I have decided on plain enamel . Its not the most robust paint (quite soft), but it makes life easier to use, as I am doing my own painting. I've gone for white colour scheme on the body and tray etc. Chassis will remain drab olive. I painted some of the underside chassis etc with a brush. The finish is not so nice, but at least I don't end up with overspray all over the place.
Warning: polyurethane paints were used by the military and the vapours including sanding dust can be dangerous to your health. Make sure you are wearing PPE respiratory protection when working with this type of paint (or any paint for that matter). I see no point in sanding off the existing paint where its well adhered. Its a very hard paint, and a good base for other paints. Just make sure you give it a light sand and degreasebefore you paint over it.
My wheel column has 36 splines at 24.5mm diameter. Took a while to find the right combination of parts. I purchased a Freightliner 18" wheel and a 5 bolt alloy Freightliner truck hub to suit. Note: I needed a wheel puller to remove the steering wheel. They are available on ebay for about $20.
- Main Air - MANN C27 585/3
- Oil cartridges (two) - MANN 932/4x
- Fuel (two) - MANN BFU 700x
- Steering - MANN H 601/6
- Cab air - MANN CU1836. This one is very expensive for what it is, due I assume to the rarity (perhaps no one bothers changing them, so production quantities may be low?). As an interim measure, for the spare, I have used a local reasonable priced alternative product from Ryco (model A268 (A92)). It will not have the same air flow, as its not as deep. One has to fit a cover plate over it to block the open end. I did this by reusing an old MANN filter end cap by cutting off the filter mesh part, flattening it out slightly and turning the plate facing the oppose way to seal against the Ryco filter. Works fine.
Oil Capacities & Drain Plugs
A very experienced BenzWorld.com member advised me to first replace all oil drain plugs with good magnetic ones. This I am doing and it makes very good sense. Two good brands with reputedly strong magnets are: 'Dimple' and 'Gold Plug'. Here's what I have measured and purchased to date (I paid on average about A$50 each):
- Portals measure as M18 x 1.5. Gold Plug AP-05.
- Engine sump measures as M26 x 1.5 and gearbox measures as M24 x 1.5.
- Differentials measured as 24mm x 1.5 tapered plug with 14mm female hex socket. Dimple M24 x 1.5 tapered see below (blue product).
- Main gearbox case has 3 plugs (same plug as differentials). Two are drains and the highest one is the fill. I measured as 24mm x 1.5 tapered plug with 14mm female hex socket. Dimple M24 x 1.5 tapered see below (blue product).
- Clutch/PTO case has a fill and two drains. There is also an inspection plug below the clutch bell housing which should be checked every so often for seal leakage issues.
I will update this page once I fit them all, especially if they don't work out, so don't take my word on the sizes.
With the steering oil, I ended up using Dexron II. Very hard to get however.
Pneumatic System - General
One of the important things to do with an old vehicle like this, is to clean out the air system, as its sure to be full of gunk if mine is any example. The vehicle relies on a clean reliable air supply, so the tanks, valves and tubing etc need to be clean. Tanks may need to be de-scaled and ideally sealed against rust (I used Red-kote and surprisingly it worked great). It binds with rust but does not like sticking to shiny smooth surfaces. As all the inside surfaces were surface rusted, it seems to have sealed the insides well. Only risk I can think of, is that if any of it peels away, it could start to block regulators etc. Time will tell.
There are 3 reservoirs (2 high pressure, and one low pressure) that needed cleaning out. I did this by:
- Removing tanks and stripping them,
- Added a handful of old screws, nuts bolts etc inside, shook violently to knock off rust scale from inside, then emptied out,
- Flushed with petrol to remove oily residue,
- High pressure blasted inside with water,
- Dried out,
- Coated inside with Red-Kote,
- Cleaned threads of Red-Kote,
- Removed all external surface rust from stone chips, sanded and repainted.
I have added another auxiliary tank for: air horns, air ride seats, pneumatic mast, tyre fill points, etc along with manifolds, regulators and control valves.
If your vehicle is like mine, a significant number of the air line olives will be frozen (corroded) in place and will not easily separated. I have to be patient and use penetrating oil and occasionally some heat and plyers. When refitting the olives, I'm using Loctite aluminium anti galling thread compound on the olives. Be advised that its easy to damage sealing surfaces and some replacement parts are next to impossible to purchase. Most of the air fittings on my vehicle are Voss brand.
The piston compressor on the ADF vehicles is belt driven. Some claim its reliable, some claim its not. There is an optional direct drive piston compressor which (in theory) can be fitted to the side of the engine by removing a cover plate. I'm not sure that there is room for it on this vehicle however? I will stick to the belt driven version and see how it goes (the military boffins must know what they are doing!). The output from the compressor is quite high (about 1.8MPa). The vehicle high pressure system needs to build up to about 1.2MPa before the park brake actuators (connected to the low pressure system) will release. The belt is long, and the only way to remove most of the slap was by increasing the tension.
The air from the compressor is regulated down for general use on the vehicle. There are dual reservoir tank systems. One system is regulated to about 700kPa and the other about 900kPa (not sure why they are different yet?).
On my vehicle, most of the small air fittings with olives are Voss brand. One of the Tee fittings was cross threaded and needed replacing. I spent many dozens of hours communicating with dozens of companies around the world in order to try and find someone who will sell small numbers of these fittings. It has an M12 x 1.5 thread which is usually used for the pressure measurement points. I am going to use on of these connections as a convenient place to tap off for the tyre pressure system. Difficulty is, 12mm is an uncommon size, and I cannot find a isolation valve to suit. I ended up using an aluminium adapter. Only time will tell if its up to it?
Master Brake Actuator
The master brake cylinder is controlled by an air actuator (air over oil).The air actuator is controlled by pneumatic valves which are connected to the brake pedal. The Master Brake Actuator will need checking as air actuator cylinders are places where muck tends to build up. I have removed the air actuator from the brake hydraulic master cylinder. This can be done in theory without disconnecting a hydraulic line. Don't forget to support the hydraulic cylinder if removing from the air actuator or the metal lines might kink.
My air actuator is a Wabco part 421 517 082 0. The repair service kit seems to be part 421 517 001 2.
When I separated the two cylinders from each other (air actuator and master hydraulic cylinder), about a cup of hydraulic oil spilled out. This indicates to me that oil has leaked past the hydraulic piston seals hence, the hydraulic master cylinder may (one day) need an overhaul. I have purchased a service kit (about 175 Euros). I will probably leave overhauling the hydraulic cylinder to the experts.
After pulling down the Wabco air actuator, it was in good nick, with no signs of corrosion. I only needed to clean, spray paint the slightly rusted mating surfaces, grease up with silicon based grease and fit a new 'O' ring before reassembling.
Brakes - Pneumatic/Air
Park brakes are only on the rear. One of mine was not working (only noticed from an underside inspection). The parking brake lever device on the hub is spring loaded, so watch out when the pivot pin is removed, as the lever will fly towards the wheel direction. I put a piece of timber between it and the wheel to soften the shock as it sprang across, and to keep the park brake on. Be careful with disassembly of an actuating cylinder, as there is a bl**dy large and dangerously powerful spring inside. As I dismantled my first unit, it exploded apart on undoing the last screw. Good way to get injured. I should have looked up the diagram before pulling it apart to see whats inside. I recommend a hydraulic press for disassembly and re-assembly. Unfortunately I don't have one (nor a special tool), so I am going to have to pay someone for re-assembly? I found rust impregnated greasy gunk inside one, and dry surface rust powder inside the other cylinder. Both are different designs and brands and all components different (nothing the same except the ball bearings and outer rubber boots). One is Wabco (a newer design) actuator, it uses a rubber 'O' ring to seal the two halves and the cylinder bore is epoxy resin coated to resist corrosion. The other is an older June 1986 GrauBremse (likely original, part 344 016 001, DB 009 420 6818), uses a paper gasket and the cylinder bore is zinc steel. I thought the Wabco unit was in disgusting condition inside, until I opened up the original GrauBremse unit (shocker). I have tried to buy the service kits. No one seems interested in selling me an OEM version, and the Mercedes kit for the Wabco unit was too expensive for a few bits of plastic. I will have to do without the service kits, and refurbish as best I can. I would have liked to replace all the rubber/plastic wear surfaces, but will likely have to re use them now. They seem still serviceable (just), and with the new air system filtration kit, hopefully less gunk and rust should build up in future. I bought a Viton replacement 'O' ring easy enough (turned up the next day), but made the gasket for the GrauBremse unit. Both have surface rust areas inside the cylinder walls, possibly allowing the piston to stick (I suspect). I tried Red-Kote inside the cylinders (because I had some left over from sealing inside the air tanks) but it was a mistake, because it is a flexible product and is not hard enough. I had to remove it (not an easy task) before I hand honed the insides to make the bores smooth and then clear epoxy coated the inside bores. The risk with painting the internal components and epoxy coating the internal bore, is that the coatings break down over time, wear off and gum up the air bleed vent aperture which is only about 2mm diameter at best. For re-assembly, I had to organise a mechanic to compress the two halves (due to the large spring inside). Not worth my buying a 100 tonne hydraulic press just for this one off purpose. For testing, I was able to control the park brake actuator pistons positions finely to any position by adding external air to the park brake reservoir using a needle control valve. See 12th photo showing temporary brass needle valve at bottom of photo used to regulate air flow to adjust park brake actuators positions slowly. Left it pressurised overnight and found that the park brakes are still fully extended the next (meaning no significant leaks).
Brakes - Pads
All hub discs are ok for a while yet and front brake pads are ok with 10mm on them. Discovered that one of the rear pads compound had mostly disintergrated, leaving the metal backing plate squewed and partially jammed (see first photo). Lucky it had only recently happened so no damage to disk. Tricky to get the pad out when in a mess like this. According to manual (G 603 page 127) there are two adjustor screws. The outside one needed penetrating oil for a day before it would budge (worth waiting before risking forcing something). See the second and third photos showing the hex key in the adjusters). The adjustment screws actually worked and wound the pistons sufficiently away from the pads to get the old pads out. The disintegrating jammed pad could only be removed by chiseling away at the remaining compound, in order to remove the backing plate.
Conclusion: The pads were clearly old and had not been replaced for a loooong time I'd guess. The side that had not disintergrated had delaminated from the backing plate and was not far off, flying apart. The sensor wire had broken off hence no warning light on the dash. Note: Pad wear warning system is not fail-safe design, and not designed to warn of catastrophic failures. It pays to check the entire braking system from one end to the other with these old girls. Clearly, whilst the army had done a lot of maintenance over the years it had missed inspecting this wheel for a long time. In fact this whole wheel hub needed much more work than all the others in cleaning it up, repainting etc. This, combined with the condition of the park brake actuators means I had to check everything, as some parts clearly have not been refurbished/overhauled since the vehicle was built.
Air Dryer - Retro-fit Kit
I wondered why everything in the air system was gummed up with crap and fine rusty dust mixed with oil etc. Answer: There is no filtration or auto water removal system !!! I guess the military want simplicity with less things to go wrong. This dust/rust/oil/water mix however, does eventually damage/wear-out seals (eg: parking brake actuators) and stuffs up the air regulators, causing much problems.
I discovered that a special retro-fit Air Filtration kit (from General Pneumatics, Victoria) purpose designed for the military U1700L, was unavailable (see picture of box below). I was very lucky, to come across one on ebay.
The kit is cut in to the output of the compressor. The kit includes a wet tank and an auto water dump valve system with timer. The kit may be difficult to buy nowadays but the separate parts can be purchased anyway. This system saves against having to manually drain the tanks every day. I do recommend this kit. I would have liked to have it all contained inside a protective box (might do this one day) but for the moment, the task is to get the air system back up and running and stop the air system corroding/degrading further. In order to fit the kit, one has to cut into the main steel 18mm high pressure line from the compressor output. The kit came complete with fittings to suit the 18mm high pressure line, in order to divert the air through the filter system via flexible braided hoses supplied in the kit. The photo shows two standard fittings used to break into the existing 18mm steel line however, I had to find alternative fittings in order to change the direction of the hoses to better protect them from underside damage (otherwise the kit all goes together very well and mostly self intuitive using the photo on the box). Note: It releases (air/water flush) air on a regular timing cycle, so probably uses up more air than doing the tanks by hand, but at least its automatic. Also note that the kit contains shuttle valves and other moving parts that need maintenance at intervals to ensure they are working ok. I have a copy of the manual for the kit, if people need information.
Hydraulic Wheel Jack
The military jack (if you are lucky to get one) which comes with the vehicle (drab olive green shown on left) is sticker rated at 10 tonnes, but built like you would expect a military piece of hardware, and very heavy. My cheap back-up jack (small blue one on the right) with yellow extension tube, is supposedly rated at 12 tonnes, and has pneumatic option as well. The Mil Spec green jack shows up my cheap blue jack as being a relative toy in comparison.
Its apparently illegal to leave a vehicle unlocked and unattended for more than a set time period or distance, in Australia. So I replaced the door handles with key locking versions. I purchased more modern square style lockable Febi door handles direct from Febi. I had a locksmith set both door handles to the same key. The existing ignition switch (Neiman 0310 style) has a captive slotted key. I purchased an ignition key barrel from Ben Nash and changed over the ignition barrel myself, as the locksmith seemed unsure how to do it. Need a fine slotted jewelers screwdriver to pop it out. See page 2 for details on how to modify the existing door mechanisms if you are game (a very fiddly job). The down-side of changing the handles to locking version, is that I have to always use a key to open the door. Its a safety risk if trapped in an an accident and someone tries to get to you in the cab. May have to change this design later?
Alarm system installed and now covers bonnet, doors, tool boxes and other odd items.
Dash & Associated Electrics
I added a forward junction box made of 316 stainless steel with nylon cable glands fitted to keep it water proof. Photo shows cable glands fitted before cabling installed. I could have fitted stainless glands and flexible steel conduit for security, but I figure there are a hundred other places a saboteur can disable the vehicle so, little point armouring all cables.
One of the circuit breaker banks in the cab has a cracked support bracket. These plastic supports are extremely fragile due to age. New ones cost about A$400 from Mercedes (so cheaper to manufacture supplementary support to the existing bracket using plastic). I had some brackets made up by a plastics engraver to provide more support.
I have added 4 x new heavy circuits (with 13mm square, multi-strand flexible copper cables), with high speed 32A HRC fuses located next to the batteries. Sub circuits run off these, incorporating standard automotive blade style fuses.
The drivers dash facia was slightly warped after much abuse. The only way to make it new, is to pull it out and panel beat. See gallery photo below.
There are a lot of warning indicator light plugs behind the facia, so mark all of them all before you disconnect them (I also too a photo of the order of the indicators before I started). I discovered that the Australian bull dust is maybe electrostatic (maybe due to the iron ore in the red dust?). Its too big a job to remove the dust from the wiring looms (and essentially impossible, as nothing washes it off), so you might need to live with that. Most of the original wiring is starting to get stiff and brittle, so watch out.
Started running the wiring looms for the basics (radios, alarm/immobiliser, black box and engine/turbo system monitor). Picture below, shows a portion of what to expect. The electrics are a lot of fiddly work and you need a sharp mind to keep track. Below shows the dash and controls/monitoring essentially finished.
The MadMan engine monitor is shown just above the ignition switch. It has an in-built warning light and noise maker. The Auber Turbo monitor (below photo) is shown above the headlight switch. It has a warning light with noise maker to the left of it.
The above photo shows how bright the gear light (green) is, due to LED's fitted in lieu of the standard incandescent bulb. Further below shows the wiring looms run into the passenger side ready for termination. The entire passenger side of the dash is full of security equipment (not a job for the faint hearted). No room for radios even, so they are down at the gear shift lever lever, mounted off the floor.
I usually (unless I forget) thank God in faith for bringing us home safely before a road trip. He was again been very kind recently, when I was shuffling the vehicle in the yard in preparation to taking it across Sydney, when the steering suddenly went hard and I thought I was at hard lock. I looked down to see where the wheel position was, and saw that it was straight ahead. Jumped out and saw oil all over the driveway. My steering oil pump high pressure rubber hose had blown. So much better that it happened at home compared to what might have happened out on the road. The steering is almost immovable without the power steering. I was going to buy MB genuine hose assembly but balked at A$350. I took it to the local Pirtek shop and they re-made it for me at A$140 (and much stronger). Below are photos of the original hose assembly and the repaired one. This is the risk of buying a 30 year vehicle, a lot of the rubber is going to be perished. Its too unaffordable (and simply impractical) to change everything, so the hope is that nothing dangerous happens as and when the various seals etc fail.
I just discovered that there is a filter in the oil reservoir (I did not know it was there). Its MANN part H601/6. Difficult to get in Australia Mog Central has some however. The next issue was to try and find out what was the correct oil. It appears that there are many oils nominated in the various manuals and documents. After much discussion on the MB Forum web site, I settled on Dexron II equivalent and purchased Castrol 'Power Steering Fluid' from Supercheap Auto Item No. 309869.
Toe-In and Camber