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1960 Unimog 404.1
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Discussion Starter #1
I'm looking for some transmission help from 'the collective' [:)]

I have a 1960 404.1 Radio Truck w/ the 2.8L engine & have burned up one transmission and am having trouble with the second one. (seems that many others have had the same problem with the 2.8 engine)

Here's the symptoms of my current tranny:

-works fine when the truck & tranny are cold - Shifts through all 6 gears with no problems.

-as it heats up, the gears begin to bind - starting with 6th. (I've had to limp home in 3rd b/c it's the highest gear I can use *ouch*) If I leave it in gear, it locks up & the truck skids to a stop.

-as it gets worse, neutral (for 3rd-6th) behaves like it's still in gear (feels like 3rd) 1st & 2nd still behave normally though it has been hard to make the transverse shift to get to them)

-draining the oil & removing the plates reveals clean oil with only a very small amount of metal shavings - some brass, some steel (probably as a result of my grinding the gears as I try to shift when it begins to bind)

-looking in the transmission, some of the gears are blackened, but not blue. Nothing that I can see looks out of place, but I have little experience & can't see all the parts obviously.

Any help anyone can give me would be greatly appreciated. If I can avoid replacing the tranny, it would be nice.

thanks,
_luke
 

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Unimog 404 DOKA
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Transmission Help

I dont' know how much help I will be but a couple of things -

This shouldn't be the norm, 2.8L's are not known for burning up trannies. I have had a few 404.0's and most of them run just fine as long as you don't cruise all day at 100KMH. The 2.8L doesn't add alot to your top end speed (maybe 10 kmh) it just allows you to maintian speed, especially on hills.

Did you put in a used tranny ?
What type of Oil did you use?
How fast do you drive and for how long?

Sounds like tranny death syndrome - ie the locking up.

A good synthetic should help you to keep the tranny cooler.

My paranoia usually makes me watch my external tranny temp guage religiously, once the temp climbs above 230F I usually give it a rest. I don't think it's the heat but most likely the bearings (needle bearings instead of ball or roller) that cause the heat buildup. My understanding is that the bearing grooves get clogged with deposits.


Good luck and I truly hope you don't have to change your gearbox again.


Chris M
 
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