When I rebuilt my 142, I partially disassembled the transmission and overdrive and replaced all the easily accessible seals and gaskets. This included the front seal and the little rubber O rings on the front cover retaining screws. I haven't pulled the transmission to confirm the source; but, 5 years later I seem to have a small oil leak from the front seal.

The service manual did not provide any specific instructions with respect to the front seal replacement other than don't forget the O rings. If I am going to drop the transmission to do the seal, is there any specific trick to installing the new seal correctly or did I just have bad luck when I installed the seal in the front cover.

As an aside, the transmission only seems to leak after use. When I pulled it out of storage in the spring or if it is parked for an extended period, it does not seem to continue to leak. I may have slightly overfilled the transmission. Would this contribute to seal leakage at the front.

Has anybody tried ATP stop leak on an M41? I am really not looking forward to dropping the box.

Which shift cover, early with the long shift handle used through 1971, or late with short shift handle used from 1972-1975?

I ask because the later shift cover has a replaceable seal for the shift shaft which sometimes leaks only after use.
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Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502
hiperformanceautoservice.com or oldvolvosonly.com

1971, so the early long swan's neck shift lever.

That rules out the shift shaft seal, as it doesn't have 1.

I wouldn't use anything but oil in the overdrive. We had to rebuild an M46 that had a "J" overdrive and it took longer to clean since the owner added a chemical"stop leak" which gummed up the works.

If it is leaking from the front of the transmission, you will have to pull it to find and fix the leak.

My brother rebuilds at least half a dozen M40/M41s per year and and he insists on the original Volvo front seal.

He also puts a little oil resistant silicone on the little o-rings and uses red Loctite on the threads.









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Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502