Home Page of Our Unimog Restoration & Camper Project
- Free from condemnation of sin
- Free from the power of sin
- Free from the penalty of sin
- Free from the practice of sin, and eventually,
- Free from the presence of sin.
Above shows the original vehicle on the day I drove it home from Minto auctions (outside Sydney) condition unknown October 2017.
I have never served in the armed forces. I have adopted the UN scheme to reflect the vehicles heritage and because the United Nations exists to try and do good. Also, there are only two legitimate colour scheme choices to pick from (in order to comply with the NSW rules for Heritage registration eligibility, camo or UN). As camo is very common, I went for the UN look and registered it under the scheme (save a lot of money). It did not help me in the end, as they withdrew my registration due to having the bling (shiny fuel tanks and exhaust etc) The ADF sent UN Unimog's to some peace keeping actions. The below photo is of an Australian Unimog with UN colour scheme (see below, Conflict: Namibia (UNTAG), 1989-1990). When these were returned to Australia, they were painted over with camo again (according to one Facebook forum member who did some of the painting whilst serving in the ADF).
- Unimog Owner's Group Aus.
- Unimog Do It Yourself!
- Unimog Owners NSW
- Unimog Owners Support Group Queensland
- Unimog and expedition camper
- UNIMOG Owners Vic
- Unimog and expedition camper
- Australian Unimog Community
- Unimog Parts For Sale
- Ex military buy swap and sell
Note: The person that gave me the idea of this Life Log page has already refurbished a Unimog and travelled extensively, see Bill Caids amazing web site www.billcaid.com
VEHICLE REGISTRATION in NSW - a WARNING:
- 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 for information. Likely to be on the computer every day for some years....
- vehicles are usually life expired and 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. Hydraulic hoses (eg steering pump) in particular are of concern. 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. This means a lot of work to make them comfortable,
- engineering certificates may be required depending on the type of modifications (eg; changing wheel type, exhaust direction, adding fuel tank, etc),
- 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 normalcar 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. In this example, I ended up buying the felt strip from Clark Rubber (took a long time to find the right profile however),
- parts are generally very expensive compared to your run-of-the-mill Toyota 4x4,
- a 30 plus year old vehicle is likely to have a lot of wear and backlash in the overall drive train, and the noise level may be very difficult to come to terms with. Sound proofing is not very successful (in my opinion) in these vehicles.
I have no idea as to whether some of the more weird variants (radar etc), will ever come on the market but AFM is tasked with the job of 'de-militarising' them before they go to auction, thus armour for example is removed and I don't imagine they would let a radar dish/generator be released into civilian hands.
Unimog 435 Series General info
- 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
- 4 wheel disc
- Voltage 24V
- Trailer socket NATO 12-pin
- Winch Werner 62kN. Cable length 30m x 14mm Steel (synthetic cord not suited)
First things First
- Check condition and level of all fluids (replace 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 after the compressor.
- Check that the rear park brake air actuators are functioning properly and in a safe reliable condition and adjusted right. They will likely need removing and stripped down to do this properly. Warning: There is a large powerful (potentially dangerous) spring inside. You might even consider replacing them, as they will likely be worn and can jam ON or jam OFF and also be a source of air leakage.
- Inspect the brake disks and condition of brake pads.
- Winch pulled down, refurbished and painted.
- 14mm winch cable.
- Rear park brake and main brake actuators removed, refurbished, re-installed, tested.
- Air tanks and system etc removed, cleaned up (tanks coated inside with epoxy sealer), re-installed.
- Original seats removed, adapter bases made & new air ride super heavy duty seats installed.
- Cabin roof lining and internal odds refurbished.
- Added auto drier filter/drain system to air system.
- Front guards panel-beated as new.
- Rear guards panel-beated as new.
- Freight liner steering wheel and hub.
- Straighten front bumper.
- Small welds to fix holes in roof and passenger door.
- Soundproofed underside and inside.
- Stripped out cab and doors and replace most rubbers.
- Repaint cab (inside and out).
- Repainted underside of vehicle chassis (drab olive).
- Manufacture and fit fuel tanks hangers and adapter brackets.
- Fitted long range fuel tanks (316 mirror polished from F650) including piping and level sensors etc.
- Relocated batteries under bonnet.
- Fitted custom tray head board.
- Added front underside front protection crash bar.
- Canvas covers for cab air conditioner, masthead flood lights, spare wheel, crane, rear folding steps, etc.
- Replaced all engine belts and idler pulleys and bearings.
- Replaced all filters.
- Tubed up new low pressure air systems (for: air horns, seats, tyres and telescopic mast).
- New turbo.
- Turbo intercooler.
- Replaced exhaust with stainless: new muffler and vertical stainless stack.
- Added bracket for tilting the cab safely (using hydraulic ram).
- Custom tool boxes front of rear wheels.
- Replaced cab access steps with 316 stainless arrangements.
- Fitted 12m telescopic pneumatic lighting mast to barge board on passenger side.
- Engine / drive train: monitoring/warning systems.
- Cabin air conditioning (with compressor fitted under bonnet).
- Headlights refurbished.
- Remote door locking modules installed.
- Security alarm module fitted.
- Black box video and data logger accident recorder.
- Camper module installed.
- Large storage box fitted.
- Crane for spare wheel installed.
- Spare alloy wheel purchased and secured.
- Spot lights fitted.
- 300l of water tanks fitted.
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 and started painting vehicle.
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. I used synthetic oil in portals.
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 in Melbourne (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 and rust in general, eg the dozens of layers of paint on the portals/hubs and the winch with the curved surfaces (took it back to the original primer).
Its Nov 2018 and I have recoated the underside of the cab with a synthetic tar-like coating. New turbo is in, and tested ok. Made up exhaust pipe in stainless. Tacked together and took to professional for full welding, modified new muffler and installed.
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 supporting 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. 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 was shiny aluminium, but I eventually painted it black (using radiator paint) so that it does not stand out.
For a boost pressure sensor, I welded a 4mm thick plate to the aluminium tube just before the engine air entry point and drilled a hole in it.
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 the unwanted superfluous brackets off the rear wall 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 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 (at a fraction of the MB price) and which worked fine. Hell of a job sliding the felt strips into the door frames.
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 and anything it touches is ruined.
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. 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 . 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. However, expect to find that its still not quite correct. I usually end up trying 5mm either side of what I think until I get the right length (trial and error because they can be too short and hard to install, or loo long and run out of tension adjustment).
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.
9th Dec 2020
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 put the original brush-guard back on the front (even though it does look horribly ordinary and commercial).
Note that the chevrons in the above photo on the rear are not legal (cannot have them only sloping in one direction).
Mundi-Mundi Trip April 2022
First long run. Sydney / Mundi Mundi plains north of Silverton (about 2500km round trip). Checked all fluids before leaving.
Regular stops and checking of portals, diffs and transmission showed all in excellent temperature range during the 2 week trip. On the good condition flat roads, vehicle was comfortable sitting on 90km/hr at 2600RPM.
Unfortunately 5th and 6th selection got worse on the way back just before Sydney at Bathurst. Did not want to risk damage, so I had it delivered rest of the way home on a low loader (see photo below).
It's 26th August. Gearbox is out and crated ready to be sent off to Unidan. Kilometrage: 114,400 (previous speedo) plus 88,765 (on new speedo) = 203,165.
Transmission Removal - June 2022
Aside from the traditional Mercedes Benz dealer workshop, there appears to be only a few companies that can rebuild them in Australia (Unidan and MogCentral). Its a significant job for me to lower the transmission, as I don't have a workshop. Many thanks to the people on the Facebook pages for advice on Unimogs in Australia. The most difficult jobs are disconnecting the output shafts due to the torque tubes. Its apparently possible to remove the transmission without lifting the cab (but awkward). The standard way to lower the transmission is to remove the tray so that you can get access to use a block and chain shackle from a overhead structure and lower it down to ground on to a pallet jack. Its all too much work for me to bother removing the camper and the tray.
Gear Selector: Disconnection of the gear selector was a bit tricky, but the Facebook gurus came to the rescue. Just needed to loosen off the two clamp bolts and the universal joint just unscrewed off by hand. When putting it back, its not really a critical adjustment. Main thing is that the gear lever does not interfere with anything.
Transmission input shaft: I used the starter motor to rotate the drive shaft (gearbox in neutral) so I could progressively get access all 4 bolts on the transmission input shaft flange. 15mm ring spanner. I had to grind a little off the thickness of the ring spanner to get at two of the bolts. I had to use a lump hammer to tap the spanner. Once the 4 were loosened, I used a large screwdriver to progressively inch the flanges apart as I wound the bolts out. Probably a good idea to mark the position before disconnecting. Note: New greasable Universals were fitted to this shaft about a month ago (purchased from Mog Central) .
Rear Drive Shaft: In order to get access to the torque tube bolt heads, the rear rubber cover can be loosened and then slid backwards. I tightly chained the rear torque tube up to the tray frame so that it cannot drop. I suggest don't use rope as it will stretch. I used a 1 tonne ratchet winch (Bunnings) with chain attached to the rear of the vehicle to pull the torque tube backwards. I used the jack to be able to move the tube up and down a bit so that the drive shaft flange would pull back without dropping. I progressively loosened the torque tube bolts, winching it back a little each time, and did this a few times until the bolts came free and then slipped a piece of timber into the gap to ensure that the gap cannot close up whilst I am accessing the 4 drive flange bolts inside with my fingers. It was filthy black moly lithium grease inside, so probably a good idea to wear gloves and overalls. The vehicle moved a bit when I ratcheted up the torque tube, but not enough to cause any issues. Accessing the 19mm head bolts on the drive flange was a difficult job as the clearance on two of the bolts was near impossible. I had to cut down the length of a ring spanner to be able to get it into position to rotate it enough (one spanner notch at a time). Needed a range of different offset ring spanners. Ideally, I would be able to jack up one wheel, release its park brake, and rotate it, to align the flange bolts vertically (but there would be some risk of vehicle moving this way). As it was, the bolts were at about 45 degrees, making it a hell of a job. I also placed a stand under the tube to help keep it up (belts and braces). Whilst the manual quotes torque settings to do the drive flange bolts up again, I'm not going to be able to get a torque wrench in there, so I'm going to tighten them up based on how tight they were originally and using experience (they were quite tight, all requiring a lump hammer to tap the ring spanner to undo them).
Front Drive Shaft: Similar deal for the front tube, as the rear. In order to get access to the torque tube bolt heads, the front rubber cover has to be removed. Chained up the front tube to stop it dropping. It was not as hard as I first thought accessing the bolts around the front torque tube cover. Got them all undone easily, and slid back the cover out of the way exposing the white nylon plastic half shells. Someone had used a generic red grease on these. Not correct grease. As best as I can tell, a lithium grease should be used. I needed a 4 tonne ratchet winch and jacked up the front wheels to allow them to move freely, and it made a difference. I was barely able to move the tube, but I managed to open a gap justbig enough to get access.
Removing the Transmission: The 4 bolts on the drivers side were relatively easy to undo. But the passenger side 6 bolts were very tight (22mm bolt head) . I used a torque multiplier tool to loosen these 6. Take a note of the spacers between chassis and the transmission before you drop it out. Mercedes Benz recommends replacing the 10 mounting bolts with new. I'm probably going to re-use mine if in good nick.
Plan A: I have bought a small piece of 20mm thick formwork ply from Bunnings. I have screwed battens to it to match the underside profile of the transmission, and cut some slots in the ply sheet so I can strap the transmission to the ply, so it cannot shift too far. I have cut many battens to length, so that I can stack them ziggurat style on top of the pallet jack to reach the gearbox. I was planning to progressively lower the transmission using a pallet jack (which has a 90 to 165mm height range) by removing one layer of the battens at a time. In retrospect, the 20mm ply would not be thick enough with the spacing of the jacks shown (I should have used at least two thicknesses screwed together).
Plan B: I have now decided to remove only the gearbox. 5th and 6th photos show a much smaller ply cradle (set up to support only the gearbox), on top of the scissor lift table (500kg rating). These photos are before I secure the box to the table using ratchet straps. Note; when removing just the gearbox, the drivers side of the transfer case is no longer supported. Thus, it is a good idea to support it.
Checked through the entire service book and noted:
- 'Contract Maintenance Sec. F.M. Mech. DNSDC' overhauled the transmission at ~114,000km in 1998.
- Transfield Services rebushed gear selector due to crunching in 6th at 158,872km in 2005. I have yet to figure out which part of the gear selector this is?
Removing the Gearbox - August 2022
I decided to remove the gearbox only. Warning, this vintage of gaskets will likely contain asbestos.
Here is what I saw:
Photo 1: Front cover plate removed. Photo 2: Front thrust bearing observed behind cover plate. Note: My box had two end float shims (1mm and 1.8mm) on the font side (behind the main cover plate). The ADF overhauled the transmission at 114,000km and engraved the word 'Bolt' so it goes back in the right way again. Photo 3: Scissor lift in red. Yellow jack is supporting transfer case. Photos 4 to 7: Inching the gearbox backwards. Photos 8 to 9: Gearbox clear of transfer case. Photo 10: View into transfer case after gearbox removed. This big disk needs levering off the transfer case gently and it comes off together with a big gear and two thrust bearings (caution, its heavy). Photo 11: Big gear viewed from rear of vehicle (before being pulled out). Photos 12 to 13: View from front of vehicle before big gear is removed (from rear side). Photo 14: View into gearbox after being removed from transfer case. Photos 15 to 16: Lowering of the gearbox once the long bolts are clear of the transfer case. Photo 17: Gearbox is wheeled out from under the chassis. Photo 18: Gearbox is removed by engine crane, ready to be plastic wrapped and boxed up.
Note: Once the case has been opened up it is important to immediately seal everything in plastic so that no dust can enter. Everything needs to be surgically clean.
Further info. Here is what I saw:
- Photo 1: The top centre circled hole is an oil plug that does not need to be removed. The top right circled shows two bolts that must not be removed.
- Photo 2: The gearbox is winched backwards using the yellow strap. Note: We first fitted the nuts to the long bolts and then gently tapped the bolts in order to crack the gasket seal. Warning, this vintage of gaskets will likely contain asbestos.
- Photo 3: The big disk that had to be gently levered from the rear of the transfer case (once the gearbox is out of the way). Behind it is a big gear which has a thrust bearing each side of it (see photo 5 below). The big gear can then be pulled out the rear of the transfer case with a bit of wobbling and gentle tapping with a lump of (clean) wood.
- Photo 4: Big disk and big gear.
- Photo 5: the big gear with thrust bearing each side. These look in perfect condition to me. I'm hoping they can be reused and I just need to set end float using shims?
- Photos 6 to 7: Show some worn leading edges on toothed selector rings associated with the high low rangeselector.
- Photo 8: Some heat issues associated with the above toothed rings.
- Photo 9: Shows the ring that has heat marks.
- Photo 10: Shows where the ring comes from and hear marks behind it.
- Photo 11: Took 4 hours to make the crate. Exposed gears and internal areas were plastic bagged and crate lined with builders plastic.
Cab Tilt System
- Weight (will you be able to change a wheel by yourself? I know I won't)
- Longer wheel studs likely 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 wheel.
- Possible extra load on portal bearings due to extra weight if run-flats fitted. If different tyre diameter, you should check your speedo and may need to get it corrected. My truck engineer advised that this is a necessity. Luckily for me, my speedo was reading slightly in error previously, and the larger diameter tyres actually brought it into the correct range.
- Tyre may drag on mud guard at full lock (mine did). This likely means getting the front guards modifed or raising the cab or body.
- Engineering compliance certificate needed if changing wheel type, exhaust system, fuel tanks, seats etc.
- Road 5.6T /tyre max 120psi
- Cross country 3.65T/tyre max 52psi
- Sand/Mud 3.65T/tyre max 30psi
Drive-train and Wheels
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 standardwinch. 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 (but not much).
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.
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 (and probably on fire). I was considering for a long time as to whether I should remove the run-flats. But after recently talking to a tyre expert , 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 limited distance without air in the tyre. The tyre might 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 (hopefully at a slow speed sensible speed for a short distance).
The main down side as I see it, is the extra weight, causing increased steering force at low speed, increased wear on bearings and increase in fuel costs. 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 it in soft sand). But I do know that the steering is heavy.
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.
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 in Australia, 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
- Check the part number for your wheels as it may be different to mine (because I selected and imported my own wheels).
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 might not be permitted in Australia if the vehicle is being used on public roads?
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 apparently does not always work in practice). There are web sites explaining how to properly remove a run-flat. The pictures below, shows an example of a run-flat (with bead-lock also).
First photo is of my tyre at 48 psi. Second photo (on the right) is tyre with zero psi. You can see from the second photo that it does not fully collapse. The tyre might even be sitting on the run-flat at 20psi?
Further info on my wheels and hubs
The new Hutchinson/Michelin (XZL 395/85R20) wheels (with runflats) I brought in, are for the MRAP (Mine Resistant Ambush Protected) vehicle. They are alloy two piece removable face rim. My version combination has outer component model W0-1137 B 20X10 with inner component model WI-1137 F. When fitted to my vehicle the overall width measures as les than 2.5m from outside to outside (that's the limit here in Oz). They work out to be 50mm offset inside and 50mm offset outside, from previous. Local companies are also bringing in these wheels (new and used), so its easy to pick up a set without importing your own. Note that military Hutchinsons come in various outer and inner component combinations, which can result in different offsets. There are different combination versions being imported and you should first check that you do not exceed the overall legal width of your vehicle here in Australia.
I use my IR hand held sensor to check the hubs, diffs, gear box, after every major stop on long hot day runs. By this means, one should be able to pick up any excessive wear problems as soon as practical, especially if one logs ambient and equipment temperatures.
On 19th of August 2017 I collected the four wheels from the customs facilities stacked one on top of the other on a pallet, in my box trailer. It was a heck of a job to unload and re-stack (took me most of the day and damaged my shoulder, which took a year to heal). I never thought the wheels could weigh as much as they did (and these are small by comparison to some that Unimog owners fit). These alloy wheels weigh about 220kg each (the same as an A380 planes 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 steel wheel. I have removed the drum protecting the calipers hydraulic piping in the third photo for inspection, ready for general a clean up, grease and repaint. The hubs were all disgusting. I strongly recommend checking the ex ADF vehicles hubs carefully. The protector drums are a hassle to remove but they 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 of 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 world 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 existingwheel 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 simply tightening up a nut (the bearing 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 can get transferred to a 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 of the 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. Photo six shows the 1mm plastic wheel protector disk in position just before the wheel is fitted up to the hub.
At my first drive with the run flats (Nov. 2020), I found it hard going in traffic. Very heavy on the steering at low speed. Got her up to 90km/hr plus, and no issues with vibration, so the wheels must be well balanced (by luck or good engineering)
Photo above shows the footprint at different pressures for the Michelin 395/85R20 XZL.
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:
Up side: much cheaper as tyres are used and 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, used or new old stock):
Up side: Save money.
Down Side: no warranty, no return and if not brand new, they may belife expired according to military standards. Possible need to replenish heat retarding lube if you plan for them to function as intended.
Recently however, some local importers have been offering new (old stock) for very reasonable prices. This will save you all the hassles of importing your own and prices were as good as I could get direct from the States.
Tyre pressure adjustments
- The version (often a retro-fit) which has exposed tubes on the outside of the vehicle 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.
Spare Wheel(s) storage
Wheel Guards and Mudflaps
When using my rim/tyre combinations, they added 50mm to the outside from original. This meant I had to:
- Buy wider replacement guards, or
- Have a strip of metal inserted to make the existing 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 ex ADFmud flaps, they also may have to be replaced to 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 extension edging, make sure its not from end of roll, as it will arrive twisted and not fit for use. I discovered this the hard way.
I purchased a set of standard tank support brackets (along with matching 50mm wide insulation rubber strips 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). Its hardened steel anyway, so near impossible to drill. I used 12mm plate adaptor brackets (I since realised I could have done it in 10mm) to pick up existing bolt positions on the chassis i.e. the old battery box and existing fuel tank bolt holes on the drivers side, and the oldspare wheel and tool box bolt holes on the passenger side.
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 IN (return). I need to make sure both valves are turned towards the same direction 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 US.
There are many water filter 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, which removes water and brings up a warning light on the dash if too muchwater 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 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. For the moment, I have a simple removable (pluggable) lighting cable that hangs down the mast.
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).
Mast is useful for area lighting and to place antennas when needed.
Pictures below show:
- the fitment of the mast on the headboard , and
- example of Curly Cord vs Cord spiraled around a mast on another vehicle
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 seemson 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 with the blood pressure on the brain. 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?
Brush Deflection Cage
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. The certifying engineer did not seem to have an issue with the existing 1986 brushguard.
An ex ADF model U1700 Unimog is a universal all-terrain vehicle. The vehicle includes a ‘thing’ which forms a standard essential part of the vehicle. The thing in this case, is centrally located on the front of the vehicle and consists of a winch head with adjacent structures. This forward winch consists of a gearbox on the rear of the engine, a drive shaft to the front of the vehicle and a (cable drum) head. The winch head protrudes past the front bumper and is flanked each side with protective ‘structures’ which are integrated into the vehicles chassis. There are two structures (one on each side of the winch head) are an extension of the vehicles chassis and they: ·
- provide side damage mechanical protection to the winch head,
- form part of and support the, vehicles bumper bars, ·
- are the frontal vehicle lifting points in a workshop or field environment, ·
- are the primary point of cable attachment for vehicle recovery purposes, and ·
- are the forward tie down points when transporting the vehicle on a low loader for example,
the whole configuration/arrangement being fully in compliance with the ADR’s applicable to pre 1st July 1989 builds.
Note: Second Edition ADRs are the applicable pre 1989 vehicle build design requirements and are silent in respect of front of vehicle protrusions. It was not until 1989 that the Third Edition ADR’s came into being and made provision for vehicle protrusion rules. The pre 1989 vehicle whether fitted with a winch head (or not) and or its associated ‘structures will be fully compliant with the ADRs applicable at the time of the vehicle build.
However, in circa 2012 the National Heavy Vehicle Law (NHVL) was enacted and this includes requirements additional to the ADR’s. In particular, it includes a rule regarding frontal projections. The new rule states “A thing fitted to a heavy vehicle must be designed, built and fitted to the vehicle in a way that minimises the likelihood of injury to a person making contact with the vehicle”. (Source: Heavy Vehicle (Vehicle Standards) National Regulation: Schedule 2, Other vehicle standards applying to single heavy vehicles Part 2 General safety requirements 7 Protrusions). This rule is subjective and has no definition. Note: If the intent is to comply with latest Third Edition ADRs, then some modifications will be required to the 'thing', as it came out the factory.
Pop top units may help with vehicle aerodynamics (having a lower profile), possibly saving a small amount of fuel and allowing you to get under some of the minor country overpasses, but they are not as good as full height campers, as I see it. They mostly use canvas/plastic type side walls at the top which can leak or let dust in and attract mold. They also let the heat and cold in easily. After saying this, I ended up buying one, due to cost considerations.
I have however, observed split type shell 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.
Living module Options
There are essentially four living module common options, as I see things:
- Slide-on (typically made for utes and some flat tops and very popular in the US),
- Custom built,
- Modified caravan, and
- Build your own.
I once built my own camper conversion into a Toyota minibus, 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 in the end, I discovered that one can never compete with the professionalism of commercial builds for re-sale.
Apparently, under the Australian Design Rules, a “Permanent Structure” is defined as a structure that cannot be readily removed within a short time and requires the use of tools.
Wife and dog guiding the trailer as I slide it under camper.
Side view of subframe in position (not yet secured to camper). Amazing how strong milk crates are (back up only).
View of finished subframe being rolled under camper.
A mag drill is an invaluable tool. Makes life easy for a change. Photo shows drilling holes for nutserts in the frame.
Glass fibre reinforced plastic decking meshnow fitted with safety handrail. Steps swivel to the side for use with the deck.
- Purpose built module
- Modified Caravan
- 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?
- Build your own
Shipping Container Option
Cool Box option
Fuels (for cooking, generator and space heating)
Toilets (one of the more important topics)
- 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
- According to some, the stench can be overwhelming when emptying them in an indoor space (not looking forward to dealing with my own waste).
- 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
- 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
- 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).
- 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
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 a full set of top quality engine belts, some oil and a set of filters (especially fuel filters)
- Some, recovery equipment,
- Outdoor enclosed fire place / grating,
- 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),
- Snake bite kit,
- 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 tubing (different sizes) and a range of fittings such as in-line joints,
- 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. There are two basic requirements for air conditioning (also see write up on Page 2 detailing the equipment I purchased for the cabin):
- when you are camping (engine not going) for the living module , 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 and there is cloud cover for a week.
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 under bunk air conditioners (eg: Truma) are best for my arrangement.
Low sound level is very important so as not to disturb the ambiance or adjacent campers. The inverter technology is likely best. Need to be able to run the air conditioning all night and not have the generator running flat strap. Generator should be able to run at low revs and handle the continuous load.
Another option is to simply use a common house AC system if you can find room to mount it !! The pros for a house typesystem 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 with a large condenser stuck on the side or end of a vehicle and take up a lot of room.
Camper Module Airconditioning - As Installed
After a years analysis, I purchased the Truma Saphir RC unit because its the smallest most powerful package to fit into my brownfield camper (under the bench seat). The hardest part was cutting the holes in the floor and not hitting any structural beams. Truma has a good reputation, so I am expecting lots of reliable use. Came with 1 strap, 3 air outlets and 1 large air inlet. Needed to order hose and elbows separately. 240V lead does not have a plug on it, so an electrician is mandatory to wire it up safely.
- The first photo shows the remote sensor module at the top and two of three air outlets below it.
- Second photo shows the cutouts in the bottom of the camper, under the seat position. The blue strap comes with the module, but I had to add the green strap to provide stability. There is no hard fix down feature, so straps are the go. I ran a small strip of 5mm foam around the edge of the two rectangular holes in the hope that this will enable a good seal between the module and the floor? May have to replace with thicker foam if it lets air escape into the camper.
- Third photo shows aluminium panel masked up before cutting a big hole for the large air return grill.
Note: I alsoinstalled a diesel heater because reliable bulkheat is more important if located in a cold region.
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 is almost impossible, and even more difficult to get someone to certify a bulk storage LPG tank (so the owner had to rip it out and use tiny 9kg bottles).
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, but there is no good reason why they should be quite so pricy. There is certainly a large enough market base for them (the demand is there, but the suppliers are just not interested), possibly because the diesels require more sound insulation to try and make them comparable with the quiet petrol models.
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 also. Look for the rated Watts, not necessarily the peak Watts. For me, about 2800 rated Watts is required, even for a small air conditioner.
Noise: 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.
Saw some good statistics recently on the Westinghouse iGen4500. If price is a consideration, I think its better value than the Honda EU30is or the Yamaha EF3000iSE.
Safety camera systems
- 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.
Display Monitor & Cameras
Emergency Strobe or Beacon Lights
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 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 ok. 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 is ok for me),
- 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 hubs to be fractionally warmer than the rear, as the front do most of the braking effort). Investing in a contactless infrared meter is a 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.
Note: I don't see the need to pick up the turbo temperature at the turbo inlet side (as some would argue), because eventually the whole thing equalises in temperature, and we are not running up near the limits and its not a racing car. In my case I tapped the insertion probe holder into the turbo exhaust casting on a flat spot seemingly designed just for this purpose. The advantage 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). 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).
I keep hearing stories of oil being sucked past seals and into the diff, thus starving the portals of oil and then the resultant self destruction. Various Facebook posts have been published on ways to monitor their temperatures.
At the moment, I just use the thermal IR gun and walk around and touch the hubs after a long drive to compare temperatures. An interesting hardwired product recently mentioned, is the Engine Guard EG01-2 product. Each kit has 2 sensors and a monitoring module for alarm warning. On the face of it, this seems a very interesting product, as the sensor can be fitted under a small bolt head on a hub. 2 kits will do the 4 portal hubs. Whether it can be relied on, to save your portals, I do not know.
Oil temperature - General
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
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 withtheir 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.
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. Was a waste of time and energy.
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 that's life. I also purchased a set of de-flator screw on valves. I have pre-set them to 30psi 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. I also welded Unistrut rail onto the existing 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 (or at least that's the theory). 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, it will likely to be wrecked on the first obstacle I crawl over.
The above picture shows the three steps. The lower one being the flexible hanging step. The 20mm (2 layers) of rubber hanger was too thick. I re-hung the lower steps using 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 main paint supplier is Protec. They supply the 601 series Camouflage Enamel to APAS-0165/1 . 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 origional Olive Drab?)
- 342-7165 - Camouflage Black.
- 342-5239 - Camouflage Pilbara Brown (more like a dark red). Not used on Unimogs to my knowledge.
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. Dark matt paint on the bonnet however might be a good idea from the viewpoint that it may 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 unfortunately), 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 slide-on camper. Chassis will remain olive drab. 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: the original polyurethane paints used by the military can be dangerous to your health (vapours including sanding dust, certainlymade me feel sick). 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 degrease before you paint over it.
With an air ride seat fitted, there is little room left under the steering wheel for the legs and the wheel may become too far away for comfort. Took a while to find the right combination of parts. I purchased a Freightliner 18" wheel and a 5 bolt alloy Freightliner truck extension hub to suit. Ordered themfrom the USA. With this combination, I can reach the wheel comfortably. Must be a heavy truck rated/designed wheel and not the flimsy stuff used on sports cars etc (even if they look similar). Remember that in the event of steering pump failure, it requires an awful lot of force on the steering wheel to drag the wheels around at low speeds and a car style steering wheel will likely just crumple in your hands (not something you want in an emergency, plus you may not be able to source a replacement for a while). My wheel column has 36 splines at 24.5mm diameter. Note: I needed a wheel puller to remove the original 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 have done, in fact I have put magnetic plugs in some fill holes also. Two good brands with reputedly strongest magnets are: 'Dimple' and 'Gold Plug'. Here's what I have measured and purchased to date:
- 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. Note: There is also an inspection plug below the clutch bell housing which should be checked every so often for seal leakage issues.
Don't take my word on the sizes, check them yourself.
Pneumatic System - General
- 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 outside.
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, as it might need honing out.
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 - 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. Luckily no damage to the disk.
Conclusion: The pads were clearly old and had not been replaced for a long time I'd guess. The opposite side that had not disintegrated had delaminated from the backing plate and was not far from comingapart. 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 almosteverything, as some parts clearly have not been refurbished/overhauled since the vehicle was built.
The military standard 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. The green jack is now starting to leak oil around the base seal. The manufacturer of these Unimog jacks is now called Andrew Engineering (Melbourne). They don't sell the seal kits any more, and were not interested in providing any details of the seals.
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) by making a grinding pasteand stuffs up the air regulators, causing failures.
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-into the 18mm metal output line 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. This system saves against having to manually drain the tanks every day. I do recommend this kit. 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.
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 . 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 apart.
Alarm system installed and now covers bonnet, doors, tool boxes etc.
Dash & Associated Electrics
I added a forward junction box made of stainless steel and 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.
The circuit breakers in the cab dash screw down to a flimsy plastic base. These plastic support bases are brittle and extremely fragile due to age. New ones cost about A$400 from Mercedes. One of my banks of circuit breakers has a cracked base, but as the electrics still work, it was cheaper for me to provide supplementary support to the existing bracket using an engraved plastic frame. The arrangement is not ideal, and one day the base will fall apart simply due to the age of the plastic, causing me more grief.
I have added 4 x new heavy circuits (with 13mm square, multi-strand flexible copper cables), with 20A fuses located next to the batteries. Sub circuits are run off these, incorporating standard automotive blade style fuses.
The drivers dash facia was slightly warped. The only way to make it new, was 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 took a photo of the order of the indicators before I started). I discovered that the Australian bull dust is electrostatic (maybe due to the iron ore in the red dust?) and sticky. 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 be very careful with it.
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. It is used to accurately monitor engine and gearbox temperatures and water level. 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. It is used to monitor turbo exhaust gas temperature and boost air pressure (though little chance of ever over boosting on the stock arrangement). Mine only goes up to 0.7bar (~10psi), compared to the 300tdi Disco which can go up to 20psi when I floor it (so it does need monitoring).
The above photo shows how bright the gear position (high/low range) light (green) is, due to LED's I fitted in lieu of the standard incandescent bulb. However, at night, they were blindingly bright at night before I fitted ~10k Ohm variable dimming resistor for night use. Photo further below shows the wiring looms run into the passenger side ready for termination. The entire passenger side of the dash is full of 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. In ~Oct. 2020 when shuffling the vehicle in the yard, in preparation for taking it across Sydney, when the steering suddenly went hard and I thought I was at hard lock. I could not move the wheel. I looked down to see where the wheel position was, and saw that it was straight ahead. Jumped out and 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 hose). 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 also discovered that there is a filter inside the steering oil reservoir. 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 (and maybe any hydraulic oil will work ?) But 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.
Some of the forum members advise that they can drive without the power steering, but I would not recommend it because at low speeds its very hard to turn the wheel.