Muncie 4 speed leaking from front on my 64 C2.

[Daniel B.]

Has anyone come up with a solution for this?

[Domenic T.]

Re: Muncie 4 speed leaking from front on my 64 C2.

Daniel, 2 things. 1 is that they are overfilled, and 2 they can leak out of the cluster shaft. I found them filled to the fill plug, where the book says 1/2 " below when cold. There is not a front seal in a Munci. It has a oil slinger that lets the oil drain back thru a hole in the case. Braking can cause it to leak if filled to the hole.
The other is the cluster gear shaft. It can leak out of there. A way to stop that is to back the trans out about 1/4 " and use brake cleaner on the shaft, then some RTV with a very thin piece of plastic to hold the rtv and also the thin plastic will also seal. plastic like a baggie.
If you are over filled then I would try that first. If not over filled then I would try # 2.
That will usually stop the leak. If your cluster shaft is leaking then you will eventually have to fix that, but it will go many many miles before and usually get you till it's time to rebuild.

Dom

[Daniel B.]

Re: Muncie 4 speed leaking from front on my 64 C2.

Dom
Thanks. I don't think it is over filled but that will be the first thing I will check.

Might be a good time to drop the trans and check/ change the clutch (don't know how many miles are on the current clutch assembly) and just have the trans rebuilt.
Thanks
Dan

[Joseph L.]

Re: Muncie 4 speed leaking from front on my 64 C2.

Dan
What is the condition inside the bellhousing? Is it very oily, or just a little dirty. A leak from the cluster will drain out between the trans and bellhousing. A leak from the input shaft housing will put a lot of oil inside the bellhousing. Both will cause a lot of oil on the trans.
Joe

[Frank D.]

Re: Muncie 4 speed leaking from front on my 64 C2.

Daniel, 2 things. 1 is that they are overfilled, and 2 they can leak out of the cluster shaft. I found them filled to the fill plug, where the book says 1/2 " below when cold. There is not a front seal in a Munci. It has a oil slinger that lets the oil drain back thru a hole in the case. Braking can cause it to leak if filled to the hole.
The other is the cluster gear shaft. It can leak out of there. A way to stop that is to back the trans out about 1/4 " and use brake cleaner on the shaft, then some RTV with a very thin piece of plastic to hold the rtv and also the thin plastic will also seal. plastic like a baggie.
If you are over filled then I would try that first. If not over filled then I would try # 2.
That will usually stop the leak. If your cluster shaft is leaking then you will eventually have to fix that, but it will go many many miles before and usually get you till it's time to rebuild.

Dom

That is how I fixed mine about 4 years ago and not a single drop has leaked since....this is the culprit - the ultimate method is to put a bushing in the case I would guess, but this stopgap has served me well. You want a VERY thin piece of plastic or rubber, you don't want the transmission "cocked" on reaattaching or you could break an ear off the case... And wait 24 hours after the "fix" before driving the car.

[Daniel B.]

Re: Muncie 4 speed leaking from front on my 64 C2.

Frank
I am ignorant as to the insides of a transmissions. What is the cluster? I can't find a reference in my shop manual, and where would the fluid leak be located? Would it come out in the same place as a leak from the input shaft housing?
Dan

[Frank D.]

Re: Muncie 4 speed leaking from front on my 64 C2.

Its called the "countershaft" and its the "pin" that the cluster gear rides on, a permanent, correct fix is to have a bronze bushing put in the case which is labor-intensive; this prob occurs most often on the early Muncies...the one in my picture is one of THE earliest ones ever installed in a Corvette and resides in my May 63 car.

The countershaft shown above is an interference fit and Muncies, particularly earlier ones, are notable for leaking there as they age...the hole the countershaft rides in gets egg-shaped (VERY slightly) over time and that's enough to cause the annoying drip around the countershaft.

Look at items numbered C1 (the cluster gear) and C2 (the "pin") in the following document (and related parts) and you'll see what we're discussing and also that it was the smaller (7/8") in early transmissions:

http://www.crankshaftcoalition.com/wiki/images/d/d8/Munciemanual.pdf

I'm assuming what some are calling the "input" shaft is the mainshaft; item B2 in the document.