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New unimog to me.

4K views 31 replies 13 participants last post by  james.mongiat 
#1 ·
So my buddy and I picked up a 1963 Unimog the other day and we are looking for parts.

It starts and runs out good. But has water in the oil. So I obviously need a head gasket and such. The mechanical fuel pump needs to be replaced or rebuilt as well. I can get it to run on an electric fuel pump with a switch but want to get it back to stock.

We have also kicked around the idea of a swap. But finding info about any of this stuff on the net is about impossible. I'm located in East Tennessee as well. The goal is to get it back into decent enough shape to be reliable for offroad adventures. Handbrake works, hydraulic brakes do not.
Already changed all fluids in it, used GL4 for the trans. Any help would be greatly appreciated.

With all of this said, would it be cheaper to rebuild the motor from the ground up, or buy a reman, or just do the required maintenance?

Thanks in advance fellas.
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#2 ·
For the few hundred bucks for a rebuild kit and a gasket, it might be the best bet to do the repairs you mentioned and go from there..As far as tossing in a new/rebuilt motor, it comes down to your experience and wallet size. These vehicles are pretty simple to work on if you have some simple tools and a manual (plus a working computer to ask questions on Benzworld)
Get it running and enjoy
G Vavra
 
#6 ·
Pull the head on the existing engine first... Water in the oil is probably real bad, but you could always have the luck of a saint and need a simple head gasket. Not likely but.... More likely is that someone ran it hard and blew the head gasket.. then kept running.

I've rebuilt one such head, less than a new engine but not cheap. Deciding between you really need to evaluate the head/cylinders/bearings to make the decision. The other option to ponder is a swap with a M180/M108/M130 engine from a 60s/70s 200/300 series Mercedes. Depends if you want to keep it stock or step up for a bit more power.
 
#7 ·
Bumping up power is always a good time. I have done some research to see what the best course of action would be, and I really don't want to make new motor mounts and adapters and all that if I don't have to. Finding one of those engines is a very viable option. The big question is that will it bolt right uo to the existing trans? I can make the rest happen with remote mounted radiator and such.
 
#10 ·
I recently purchased a rebuilt motor from Scott at EI and have been very happy with it. It's an easy and convenient solution to the problem. I would also give Michael at United Parts Service (Unipaser) a shout as well. I have bought many parts from him over the past few years and have always been satisfied with his prices and service.

Cheers
 
#11 · (Edited)
There are lots of thread on BW about swapping in all three of those engines (as well as the OM616/OM617 diesel) and all will more or less bolt in with minimal fabrication (with the exception of the diesel). You should research a bunch of those threads for specific details though. Here are some of the main points:
- The fuel injected versions (M127/M129/some M130) will not fit without major work (due to the injector pumps).
- The flywheel from the 404 M180 engine may be needed on the new engine. The M180 flywheel used in the 404 is externally balanced, i.e the flywheel contains a large offset weight and the flywheel and crankshaft are balanced together as a unit. Later M180/etc. engines were internally balanced (mostly), meaning each part is fully balanced separately and can be swapped independently. If moving/swapping you may need to rebalance.
- Later engines often had dual carbs, which may not fit under the hood or need custom intake hoses. (Note: The civilian version 404 had an option for dual carbs, so some combinations do fit natively.)
- Later engines often have vacuum advance/retard controlled distributors. Swapping and/or adding the appropriate vacuum lines to the carb may be necessary.
- Different engine versions had different headers for intake/exhaust direction. Swapping/modifying headers and/or exhaust pipe may be necessary.
 
#13 ·
Hi James,

We have chatted before haven't we? I am about 30 miles SW of Knoxville. May I suggest you drive a 404 that runs good and then decide about the upgrades (PM me). In addition to many threads on here about how to do the upgrades, there are many threads about upgrades that went bad, then the truck and owner faded into oblivion. A well tuned 404 is an adequate runner even on 55 mph highways. There's another 404 owner in Knoxville area and he drives it every day. It is a bone-stock screamer (with civy ignition).

How bad is that water problem? Have you drained, refilled, and watched for more water? Some cheap oil changes might be educational. Is there oil in the coolant? If you do not know the history of maintenance and use, please give the truck a chance. Louisiana is a wet place!! Down there they don't look for hills to run, they look for mud and swamp. Be sure to check your portals too.

Bob
 
#15 ·
the Crated Rebuilt M180 Engine that Scott sells at Expedition Imports is a true bargain. He used to do a test run/tune on a engine stand, and then ship for a modest fee. If he still provides that service, Do It!

the 404.1 is dead simple, but considering your questions here that would save you a ton of time learning the ins and outs.
considering the labor involved, a new clutch, pressure plate, and throw out bearing is also a wise move.

good luck!

PS: just changing the fluids and running it first would be wise, maybe the motor is in great shape... there are lots of ways to get water in the sump other than an engine fault (especially considering it came from the swamps)
 
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