Is a Unimog for me?

762X39

Explorer
A Mog is not for you. As soon as I hear "I need to go faster", you are missing the point of owning a Mog. As others have said, buy a Mercedes 4WD truck or a MAN 4WD truck or whatever.:coffee:
 
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Sitec

Adventurer
A Mog is not for you. As soon as I hear "I need to go faster", you are missing the point of owning a Mog. As others have said, buy a Mercedes 4WD truck or a MAN 4WD truck or whatever.:coffee:
And that is 1 of the 4 reasons I why I went for a 1222 AK Mercedes. The first is the speed (prolonged highway speed getting from A to B). The second is the length of available space behind a full 'cab over', the third is world wide availability of parts with a 'truck' style Merc, and lastly weight.. A nicely built body with bathroom, kitchen, storage etc seems to more often than not end up as close to the max weight permissible weight capacity of a Mog. We plan to occasionally tow a rag top SWB Land Rover behind ours too. I love Mogs and would really like to have one in my yard... But my truck and crane has already paid for itself, and the project is only just about to begin! Here's what we are aiming for......image.jpg
 

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Sitec

Adventurer
Going to need a bit more break-over angle than that if you plan on going up the Canning Simon :)
Yup, mine is a slightly shorter wheelbase, and the side skirts will end up approx level with the top of the rims. It'll be interesting to see where it will go. We have a Country Fire Service 'truck driver off road familiarisation' day coming up at Saunders Gorge here in SA and I'm hoping to take mine too! If I do I'll post pics! :)
 

Iain_U1250

Explorer
Best way to see what it can do is to give it a try. We never plan on doing the "4WDing" thing, but have on a few occasions needed at least some of the Unimog's off road ability. We travel solo, so having the best off road truck there is means we have not had to turn back when the road disappears for a bit.
 

Jostt

Adventurer
I was on the same point than you, and owning now a mog you must change the chip, but for me was not a problem, on the tarmac the mogs are not the best way ir you want to keep 90 km /h like other truks for long time, by the portals, even whit overdrive and bigger tyres my one can reach 110 km/h, but you feel ok on about 85 km/h , even at that speed I think we must take care whit the oil on the hubs, I agree whit the people , It is not for every people , I make the mantenínance of all my vehicles, including the mog, at all Im Happy whit these thinks, good luck
 

Iain_U1250

Explorer
I don't understand why people insist that mogs are slow. The fire truck versions of U1300 with the super fast axles run at 120kph, and MB would not sell them like that if there was a problem with running at that speed. I know of plenty of mogs that cruise at 95-100kph, mine has been doing that for 35,000km and the portals are fine. A modern ( if that is the right term for a 35 year old truck) U1250-U1700 with fast axles and bigger tyres will sit at 100kph @ 2800rpm, fitting a Claas overdrive will drop the revs at that speed down to around 2200rpm, which is better for the engine. A set of working gears is essential, otherwise you can't use the mog's off-road ability if you have gone with the bigger tyres/fast axle options, it is just too fast even in first gear to control things off road. Regular portal oil changes with a high spec synthetic oil, a proper breather kit on the front portals to prevent oil migration, and checking the oil levels regularly and they will last.

The problems most people get is they buy a 35 year old truck with a dubious history and expect to be able to run flat out without doing anything do it. Often they use cheap 75W80 diff oil, and have not fixed the known oil migration problem you get when driving at high speed. An ex-military mog might have been well maintained, but think about who has been driving it, mostly young soldiers who don't care on bit about the truck and drive it like they stole it. I did 2 year national service in the SADF, and we did our best to break the trucks. A fire truck would probably be the best one to get if you can find one, as at least they are driven by men who know that lives may rely on the truck, not boys out to prove how tough they are. Alternatively you can get a working mog like mine was has been worked to death for most of it's life.

I basically replaced nearly everything on the truck, only thing I did not refurb was the transmissions, and only because there was evidence of the the transmission being overhauled. Whether they did it properly, time will tell, but I am using a good synthetic oil and have changed it once already and there are no metal bits on either drain plug so I have been lucky so far.



There is no such thing as a cheap off-road truck, you get what you pay for and if you can't do the work yourself, then you have to pay truck prices for getting someone to do the work for you. If you can't fix it yourself, then you are better off with a new truck, and even then you should not be taking it into a remote place unless you can afford to pay for someone to come out to fix it.

There is nothing special about 90% of the things on the truck, and the portals are simple straight cut gears, The transmission is about the old tricky thing as there are shims and things to set up the preloads, and you need to know how to do the measurements properly to be able to put it back together.

If you are planning on driving on tar roads and the occasional dirt roads then a 4wd version of a road truck might be the way to go, but if you plan on driving off-road, and plan on needing low range and driving up the tracks that the Land Rovers and Land Cruisers drive on, then a mog is right for you.
 

Jostt

Adventurer
For sure you has more experience than me whit Unimogs, and I keep in count what do you say, jus It is my feeling after Drive another trucks on the road, but It is true my one was on the worst situation when I bought, because no over , and axles plus small tyres, about the kits to prevent the oil migración , It is some Caín of options? Or just one way, thanks
 

slowtwitch

Adventurer
Definition of 'slow' depends what continent you are on. I would doubt that a Mog firetruck (or any) rated at a given speed would be meant to be run that speed often and at long duration.
 

Iain_U1250

Explorer
Most places in the world limit the speed of trucks to around 100kph/60mph. That is fast enough for me and we have some big distances between towns over here, once you get into the Outback, 300km seems to be the average.

When MB rate things they do it properly, so if they rate it at 125kph at 7.5 tons with will do that every day all day. If the maximum rpm on the engine is 2800rpm, because it can safely run that fast all the time, not just now and again.

The reason MB trucks last is that they are engineered to be used at their rated limits all the time, not just some of the time. If an MB truck is rated at 7.5tons, that is because it can carry 7.5ton all the time under any conditions. When MB rate their truck at a wading depth of 1.2m, they mean drive into a river 1.2m deep, you can stop and park there for hours, without any negative effects, (hence the axle pressurisation system) not just splash through in 10 seconds. When a truck is used at its maximum ratings all the time, some parts will wear out faster, hence the different service categories in the manual which are dependent on use.

Some other manufacturers may rate their trucks at 7.5 tons but assume that half their life the truck is unloaded when they design the chassis, so their chassis are a lot thinner than a mog chassis.
 

grizzlyj

Tea pot tester
Hi

There was a discussion on Benzworld a while ago that I think ended up suggesting that the only known portal failures were on 6 bolt hubs like Bill Caid's. None on 8 or 10 bolt, whose bigger hubs have more oil so perhaps no migration issue. Bigger hubs designed by Merc to run 395 85 R20s, U1300l are not (normally, AFAIK, which isn't a lot).

And regardless of not too many known 6 bolt failures, there are a lot of Mogs doing a lot of miles worldwide. One or two well known failures doesn't make it a big problem for many/most/some/me :) Well, ex-U1300L owner, ex-U1700 owner and no hub failures for me so that definitely says something. Maybe.
 
Rob Blackwell had a (10 bolt) U500 right rear portal fail near Shiraz, Iran about 4 yrs ago but that was due to oil migration to the rear diff.
I am having the right rear sealed bearing between portal and axle replaced at Unimog dealer in Germany, also will have Unicat re-plumb breathers and hook up to low air pressure (~0.4 bar) for fording, normally all open to outside air thru filter. But Unicat has already told me that the right rear portal breather line was dry of oil, so it must be the sealed bearing. My portal bearings are under increased stress due to 90mm offset Hutchinson wheels (although 10 kg lighter), normal minimum offset is 110mm for 495/70R24 XM47.

Charlie
 
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evilfij

Explorer
I have been on the hunt for a mog for quite a while. I know very little, but have read and listened quite a lot.

Where I have come out is that I would like a 10 bolt, fast axles, 395 85 R20 tires, and a turbo motor. Working gears are a near necessity. Fast axle 10 bolts are hens teeth. I am told 1/100 had them. I almost bought one with the exact spec I was looking for (and still may do so), but the rust and maintenance was more than I wanted to deal with (still seems like a good truck, just not for me). Ideally, I would like a SWB too, but AFAIK, that particular spec just does not exist.

So why do I want what I want and whether it is a good idea or not. I got a lot of good advice here about going "fast." Basically what it came down to is $$$$$ and you are really going from something like 55-60mph to 65-70mph and you are spending double to do so. That is ok by me, but it means either (1) running taller tires on a 6 bolt mog and risking portal failure or (2) a claas overdrive or AV super fast ring and pinion on a 6 bolt mog and still risking portal failure or (3) fast axles on a 10 bolt or a claas on a 10 bolt (I suppose 8 bolt would be ok too but I have not seen many of them around) or (4) a US spec U500 (lots of money upfront, not sure who around me could fix it, and the price of repairs is much higher than an SBU -- I missed one at $52k in the depths of the recession and still kick myself to this day, oh well).

That is before you get to adding enough power (220/240/260 hp upgrades) which is also $$$$$.

Among the choices, fast axles and a 10 bolt seemed most reasonable as the claas is basically $10k and another failure point. Maybe I am wrong, maybe I would end up with a claas eventually I don't know.

I am also in the US I am limited to 25 years old with original motor. And I don't want to spend more than say $35-40k. OTOH, I have eight vehicles already so I can wait and bide my time until the unicorn appears (it took me seven years to buy a jag, I finally bought a Porsche I wanted since I was 16 etc.).

Is it a good idea for me? More important, is it a good idea for you? For me, I don't plan to go much of anywhere special as I don't like to go far from home (stop laughing ok?). But I do need to travel on Us interstates which are suicide at 55mph in my experience. 65mph is fine, 55mph is asking for trouble. YMMV. Basically I want an SBU in lieu of a 3/4 ton domestic pickup. Haul stuff, tow stuff, camp out of it, take it off-road once and a while. No mongolia like Charlie for me. But if you are going way off the beaten path, I can't think of anything better than a ten bolt SBU. From everything I have read they will run at full GVWR at "max" speed all day every day which is fairly optimal for a small camper. They come in extra long wheelbase and seem quite reasonably priced in that spec which is ideal for a camper and even in the normal long wheelbase they have a good sized bed. And, you have a 10,600kg or so GVWR which means weight is not the big issue it is in other builds (6 bolt mogs are typically 7500kg or 8000kg) with approximately 5000kg or 12,000lbs for load/camper/stuff. Nothing wrong with a 6 bolt, but the premium for a 10 bolt seems worth it as it is not much on the base truck and there does not really seem to be a downside to going for 10 bolt.

So my two cents anyway.

PS a Werner PTO winch seems like the business, but there are others available that would do the job.
 
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http://www.unicat.com/en/info/MD48-UnimogU2450L38.php
http://www.unicat.com/en/info/EX47HD-UnimogU2450L38.php

Something like these?
I know 4.96 was an optional gear ratio for U2450L 6x6. Both the 10 bolt U2450s above run 14.00R20 XZLs, 420 rev/mile. New 14.00s are rated 164J (62mph).
With 4.96s and 14.00s one won't need a Claas. With 6.38s and 14.00s, you will need one. Even with 6.38s and a Claas 395s will rev at 2320 at 60 mph, a bit fast.
You sure you don't just want a "normal" 4x4 US made truck which will easily do 70-75 mph, an impossibility with any Unimog?
In case you are speculating, 4.96s, a Claas and 395s will rev at 1800 at 60 mph. Might work, my calculations tell me that it takes 145 hp (at 1900 rpm) to propel my U500 camper on flat asphalt, no wind, at 60 mph. At 1800 rpm a OM366LA has a max output of about 190hp (derived from peak torque of 560 ft-lb). With this setup the Unimog will be power limited rather than rpm limited in 8th gear.
BTW, flirting with the Mercedes EPC (electronic parts catalog) tells me that you need to change both diffs and all 4 portals to get to 4.96, but if you change just the portals you'll get down to only 5.58 - still too slow with 395s.
I estimate $15K just in parts to get 4.96s.
16.00R20 XZLs are too big and heavy IMHO, though they'll fit on the rims. And they are rated for only 55mph.

Charlie
 
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grizzlyj

Tea pot tester
snipped
16.00R20 XZLs are too big and heavy IMHO, though they'll fit on the rims. And they are rated for only 55mph.

Charlie
Our U1300l had 14.5 R20 MPT 80 which I thought were heavy at the time.
Next our U1700 had 395 85 R20 XZLs which were definitely heavy. But if you are into weightlifting, changing and remounting was OK.
Next non-Mog truck has 16.00 R20 XZLs which are ridiculous. I bought two more with about 10 miles on them, rolled them out of a van and the one that fell flat stayed there until I could get a maybe 10' scaffold pole and some blocks to stand it up again. A pair of chain hoists will be used for them!

Red Bull have a tuned 6x6 MAN Kat 1 that I'm told with its new auto box changes to 8th at about 80mph, on 55mph rated 16.00 XZL :)
 
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