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After several jumpy starts and stalls, I asked my friend to turn back over my 63 w/ M20 muncie. The car began leaking trans fluid from the front of the trans between the bell housing after the abuse. The clutch now slips a little the first two releases of a day out. I decided to read the forums and pulled the motor out with the bell housing. Inside the bell house seemed saturated.
I took a pic and adied to library. Upon inspection, I did not see a retaining nut. I also saw dents on a washer-looking thing (hydro seal?) that also appears to be cross threaded on the input shaft. Do I need to rip-off the hydro seal, replace it and get a new retainer nut? Should I get a new retainer cap too considering the recent abuse? I can find a hydro seal or retaining nut on ebay or common online trans shops. Any recommendations and/or advise?
I did not see any photo albums under your profile. It sounds like you are referring to the front bearing retainer on which the throw out bearing rides. There is a gasket under the retainer and when the retainer is removed, a nut and front input shaft bearing behind that. I don't believe there is a seal in there. The front bearing retainer has a drain back hole in it that returns any lube back to the case. There have been instances where the retainer has been installed incorrectly and lube passing the bearing cannot return to the case and then it can follow the input shaft out and into the bellhousing.
More common is wear of the countershaft below the input and where it press fits into the front of the case. Over time that interference fit can become loose and lube will leak out it and run down between the bellhousing and the transmission.
I doubt your friend did anything to damage the transmission causing it to leak. However, if the clutch was old and marginal, he may have fried it if he wasn't an experience stick driver.
Try to post some photos and maybe someone can give a better response.
I don't know who lets an inexperienced driver try out their marginal straight stick skills on a vintage Corvette.
Anyway, yes, as Dan noted above, the front countershaft leak on a Muncie is a classic problem. Many just pull the transmission back a few inches smear RTV over that hole and push the transmission back. That may stop the leak permanently or just temporarily. I went farther and also put a thin piece of rubber tool box drawer liner over the leaking hole with RTV on both sides making a "sandwich" and torqued the tranny back. 5,000 mile later still no leak.
A pretty classic problem on these cars. As many people will tell you this is not a real fix but a workaround but it can suffice for many 10s of thousands of miles. IIRC there is some company that makes a case with a bushing in this hole which is prob the way to fix it for good...
Last edited by Frankie the Fink; 03-29-2015 at 08:40 AM.
I don't think a leaking cluster shaft pin can oil up the clutch.
I can't see how some jerky starts/stalls is abuse to a clutch, either. I'd examine the engine for oil leaks around the pan, valve covers, intake, oil pressure line and the press in plugs behind the flywheel.
My countershaft leak did not make my clutch slip and it was leaking pretty badly; its possible there are two problems...a tranny leak as the OP noted; and a saturated clutch disc from another source can certainly make it slip and chatter.
If the wannabe driver overheated and glazed a fluid-soaked clutch disc then that's bad news too...the level of abuse is a factor...
Few items. The main drive gear bearing has a nut on it that does indeed look like a "washer thingy." It has to be installed so that its beveled face is oriented toward the front of the trans. The beveled face is just a few thousandts of an inch from a similar beveled face on the inside of the retainer. The beveled face is called an oil slinger. It keeps oil from leaking through the retainer by "slinging" it away from the clearance area. There is no oil seal, only a gasket between the bearing retainer and the trans case. As Dan pointed out, if the retainer is installed so the drain hole isn't oriented down, oil will collect under the retainer and leak out thru the retainer sleeve. From there it's a straight shot into your clutch.
If you use Frankie's idea to seal the counter gear shaft at the case hole with RTV, using rubber as suggested is the way to go. RTV won't seal well on oil wet surfaces. If you can't keep the area around the hole dry, use gas tank sealant instead of RTV. That stuff will seal even if a hole is wet with gas or any kind of oil. Only downside is youl'll have to chip it off or grind it off if you get your trans case fixed as suggested.
I don't think a leaking cluster shaft pin can oil up the clutch.
I can't see how some jerky starts/stalls is abuse to a clutch, either. I'd examine the engine for oil leaks around the pan, valve covers, intake, oil pressure line and the press in plugs behind the flywheel.
That was my point in that it usually runs down between the bellhousing and transmission. But, in an old car can't discount it also has a leaking rear main, or camshaft plug or something that is also oiling up inside the BH.
Same with the clutch - few jerky starts shouldn't hurt it, but a lot of reving and slipping by an inexperienced stick driver could fry an already marginal clutch.
The responses on a short period of time is amazing. .thank you. I upgraded my membership because of it and so I can post pics.
On my list of to do s I have: seal retainer cap and bolt threads. Seal countershaft w tool drawer matting and rtv right before I sandwich the bellhousing..
before I proceed I wanted to be sure I didn't need to replace the oil slinger as it has some marks on it...pic attached and now in my album. Or replace the retainer cap which doesn't appear to be damaged. I don't mind a little overkill w this project if it helps assure no more leaking and prevents me from pulling the motor or trans again.
Mike..thanks. the rear main seal was leaking last year and I replaced it w the help of this forum and my inexperienced stick driver friend...the Main reason I let him drive it. The car didn't leak any fluids after replacing the rear main seal Until about 5 drives later after the abuse...luckily he knew not to over Rev the motor. I'll read the forum on taking apart and inspecting the clutch pack while it's out of the car. The leak now is definitely 100% trans fluid...not to say the old main seal leak didn't take its toll on the clutch.
Those marks are from a set of vise grips to remove that nut. The two "flats" that are to he bearing, are for a special wrench to remove that nut. I made one. And remember if you do want to replace it, although there is nothing wrong with it, it's left hand thread.
Nothing to add here other than try lowering the amount of oil slightly. Aggressive driving can easily overcome the left-hand threaded nut. When doing rebuilds, we always replace the nut. Its left hand thread as noted and should be "staked" in place. I also wouldn't use a GL5 oil with this; something like 1qt of Brad Penn "classic" gear oil (80w90).
The aftermarket case has the whole front wall redesigned and is much denser aluminum. This supports the press fit of the countershaft pin much better. There are also some really badly made Muncie nuts out there, so check your replacement nut and make sure that the threads are clean and sharp and it screws on nicely.
Check your front bearing retainer for hairline cracks too.
Dan Frank Avispa Bill Mike & 69z. Thank you all. I was able to develop a clear picture of the task at hand based on your appreciated feedback. I'm going to KIS and not try to change the retainer nut. I now have confidence in the solutions and am going to proceed. I'll give an update once I'm done in about a month since I plan on cleaning up the engine bay and repaint the motor. Thanks again!
03-29-2015, 01:25 AM
muncie m20 63 front leak after abuse
