The Stovebolt Site Forums The Shop Area Engine Shop 3-speed leak

Hi All,
I try not to post unless I've searched and can't find what I'm looking for, so here goes:

I finally got around to looking into what I thought was a rear main seal leak, and (happily, I hope) it looks like it's coming from the front of the tranny.

I believe it's a sm318, stock in my 59 3200.

I just replaced the output shaft seal, then pulled the tranny expecting to find a simlar seal on the input shaft. I pulled the front cover, and found a bearing with no visible seal other that what might be a paper gasket around the cover. There's also an open hole at the bottom of the collar around the shaft.

So my question is this: How does the front of the tranny seal? Is it just that paper gasket, or something I'm not seeing?

Thanks,
-tyler

tyler,

Typically there is a small, stamped steel washer in back of the bearing that is called a 'slinger'. As the input shaft spins, the slinger "slings" gear lube off and doesn't allow it to migrate through the front bearing and onto your garage floor.

If anything does make it out, that small hole in the bottom of the retainer allows it to drip out before it can foul the pressure plate. The paper gasket seals the bearing retainer where it screws to the tranny case but other than that, it all up to the slinger.

Sometimes, if you park your rig nose down on a steep incline it can leak gear lube. Over filling can get you in trouble too.

While I'm not 100% on this, I believe the later model transmission actually did have a mechanical seal on the input shaft. A sniff test will usually tell you the difference between leaking motor oil and leaking gear lube.

Stuart

Thanks for the info, Stuart.

I'll start exploring other possible escape routes for the oil. While I have it out, perhaps I'll give it a good once-over.