pbalias

'01 Z06. I have a leak coming from the tranny extension housing where it meets the main body of the tranny. I put it up on the lift and got it all apart, and the leak's DEFINITELY coming from the gasket there. Problem is, the local dealer doesn't show that part. Does anyone have a part number for this thing?

Pics to follow tonight after I get home from the shop.

Thanks in advance guys, Peter

heimbo

iTrader: (2)

It's just RTV, there is no gasket available.

Gary Z

Try retorquing the extension housing bolts to 26 ft-lbs.

pbalias

ok so just so you guys can VISUALIZE what i'm talking about...



and here is the tranny with the "extension cover" removed. so i guess what i'm needing is the black gasket that you see which surrounds the outer edge. from this pic it's OBVIOUS fluid is supposed to be in there:



and here's the inside of the "extension cover" :

SScam68

iTrader: (20)

Don't have a Vette T-56 but I've rebuilt 3 f-body T-56's and none of them had a gasket on the extension housing.

All had RTV from the factory.

You could give sixspeedsinc a call and ask them.

heimbo

iTrader: (2)

F-body t56 here also...just scrape that old stuff off with a plastic putty knife or soft wire brush and put some hi temp rtv in its place and your problem should go away. Just make sure the mating surfaces on either side of the housing don't have any large nicks in them.

pbalias

yeah, that's what i was thinking. we use the Permatex grey gasket maker stuff for situations like that. I just wanted to post up the pics so you guys were 100% sure of what I was talking about. this is the first time we've actually cracked the case of a T56.

QUESTION...Should I really scrape the old gasket off? it's like a millimeter thick. I'd hate for it to act as a calculated spacer for bearing clearances, etc. If i remove it, I might be violating the pre-engineered space and clearance that the gasket was designed to provide (even though it's really thin.) It's like really fused to the tranny case, ALMOST like it's not MEANT to be removed, hence the lack of a GM part number??? Maybe I should apply the silicone OVER the gasket? I don't know, just a thought. It's a relatively new tranny and I'd HATE to do something to eat it up.

Thanks a million for the insight...

Peter

Gary Z

Your concern is valid. Do not simply replace the gasket with RTV. I'm surprised to see a gasket - the f-body version definitely comes from the factory with RTV and no gasket between the main case and the extension. The thickness of RTV is essentially zero. Simply removing the gasket would greatly increase the preload on the countershaft extension bearing. Contact Six Speeds Inc. for more info.

heimbo

iTrader: (2)

Looking at the pic, you posted I was under the impression that the gasket in place was "rubber" or something similar to RTV which will compress greatly when torqued, leaving vitrually nothing, or at least not enough to cause anything to be out of spec.

On a second look at the picture, it does look like a factory seal, and a lot nicer than any sort of permatex gasket could ever be. As long as nothing was damaged in the removal I doubt you would have any leaks after you reinstall the housing.

pbalias

so just so i'm sure, leave the factory gasket/spacer intact and also use the grey RTV, correct? (assuming I CAN'T find a factory gasket)

SScam68

iTrader: (20)

I wouldn't, you don't know if the seal from the gasket has been compromised from being compressed.

heimbo

iTrader: (2)

It's really your call, but I always have a policy to try and avoid reusing any gasket unless I have no choice.

If it were up to me I would scrape and reapply a bead of RTV.

calhoon

iTrader: (6)

That ia a factory gasket that is a Corvette-only part. You cannot re-use it as the seal bead compresses on installation and will not seal well a 2nd tine around. You should be able to get that part at any Tremec dealer( D&D, Rockland,Standard ,ECT)