The Unimog U1700L driven and explained

The Unimog U1700L was used in the Australian Army and now many are owned privately. An owner requested some help with driving and winching, so helped him and made a video! Watch to learn all about the Unimog U1700L, it’s a bit of a surprise.

To drive these Mogs on road you’ll need at least a MR licence, or Medium-Rigid either Unconditional or Condition B which is manuals. Condition C is auto only. The gearbox is 8-speed but has full synchromesh so no need for complex double-declutching although that can help going from 5th to 6th as the planetary gears disengage (see video).

In the video review Part 1 I reported the GVM (max mass) as 12,300kg – it’s actually 12,000kg, I copied the wrong numbers over. Still an impressive figure.

The crawl ratio is 83:1 forwards, but remember it has huge tyres so it’s more like equivalent to a 50:1 on a normal-sized 4×4. Still decent engine braking, and remember you can engage lockers on cross-axled downhills.

Here’s a story from the YouTube comments:

Story 1

AFAIK were still in service when I left in ’98 I don’t know what superseded them, as I’d converted from mechanic to IT Systems admin in 95 and had long left the army when any replacement happened.

When I was involved with them it was in 9tpt Sqn, Townsvile, first unit to get them operationally, and at RAEME training centre, as an instructor. They didn’t have those “super singles” when I was in, instead they were issued with Dunlop “Militaires” which were the same basic tyre used on the previous Internationals instead of the lower pressure wide tyres they were designed to have. Why? I have no idea, cost I guess but they were useless and killed 80% of the offroad ability. Yes they had 8 reverse. The same 4 speed/splitter combo gearbox was just reversed.

The “Unimog” was supposed to be a universal system that had multiple attachments available, winch, train track stabilisers, forklift, crane, dozer and front end loader attachment. Army only had 1 in 4 with a power take off to use with the winch or crane (1 in 10 had crane IIRC). That winch is weak as, don’t try to winch with the rope beyond about 10 degrees either side or the auto fairlead roller will poop itself. I don’t think it’s the same winch as fitted by Mercedes.

Likewise the crane on some (1 in 10) had a weaker crane than Mercedes would have supplied, it struggled to lift and hold 1 tonne in practise… cost cutting or something I suspect <shrug>

The suspension is coil, with “portal axles” that give incredible ground clearance, the nylon bushes of the “torque tube” drive shaft system at the gearbox/transfer case end could cause problems (with the militaire tyres, super singles are softer and should be OK) They used to wear out in a matter of a few thousand K’s on a truck constantly loaded, like water tanks (one trip from Townsvile to Karumba via Hughendon on the western cape we had to swap tanks onto 2 different vehicles, then replace the bushes due to that) The brakes are air over hydraulic discs, very good, but the hand brake and caliper piston manual adjusting/retraction system was typical German over engineered and weak.

Hopefully the original alternator has been put back on (as the tyres seem to be on yours) The army in its infinite wisdom had developed its own alternator (we called it the EDE alternator, after the branch that forced it upon us.) It was supposed to be a one size fits all for all military use, APCs, trucks.. whatever. Trouble is when fitted to the Unimog it stopped the cab being tilted forward for maintenance. So you had this stupid fart around partially tilting the cab, loosening and sliding the alternator out of the way, then completing the cab tilt… And if you needed to run the engine you had to replace the alternator, which meant you had to go through the same BS just to drop the cab back.

You’ll notice the RHD version we have has a 90 degree adaptor behind the dash, a shaft that travels across under the dash to the left side of the dash, than another 90 degree adaptor that joins it up to the original LHD shaft. Works, but you’ll find that traveling any distance at around highway speed (good luck with that.. 80-90kph is it’s realistic top) it’s a hell of a lot easier to have only one hand on the wheel keeping a slight “preload” to one side or the other .. two hands you end up weaving all over the place. You’ll find a can reach under the dash and easily steer the thing with one hand by twisting that shaft…. a dirty trick to play on an unsuspecting driver….. so a friend tells me 😉

Great vehicles, stuffed up in some regards by the Army, but if returned to their original state (tyres, alternator etc) will serve you well for a very long time. The only problems we had at 9TPT were the tyres, alternator and sometimes disc brake adjuster and the headlights were weak.. very weak to the point of dangerous .. everything else was near bullet proof. Except that one they drowned in an amphibious landing exercise… that one was never right afterwards.