How to get tranny pan gasket to not leak?

Blue71 · Mar 15, 2010

Had my transmission rebuilt and sealed up with the old pan. Wasn't happy with my rattle can paint job on it so I removed it and had a quality job on it. I cleaned the surface of the tranny as well as the pan 100% clean. Inspected the pan for warpage, or places where the previous owner had tightened it to much and made humps where the bolts go. Looked flat and nice. So i replaced the tranny pan with a new gasket. Was told not to use any other sealer like silicone, etc...that it would seal fine with just the new gasket. Well..I think it must have leaked about 2 quarts out of the 4 so far that I put in. Wasn't even gonna try and fill it after I saw it leaking around most of the edges. Oh well..I drained it tonight and removed the pan. Gonna let it drip dry and clean the surface again really good. Whats the best gasket, sealer, etc to use so that this doesn't happen again.

Thanks,

Blue71

Viperwolf1 · Mar 15, 2010

No sealer needed. Use a cork gasket. Make sure the bolt holes in the pan lip are not dimpled from over-torquing. If they are flaten them back out with a ball peen hammer. Get the biggest flat washers that will just fit between the rolled edges of the pan and use them under each bolt. Tighten the pan evenly around and not so much that it causes the gasket to bulge out.

An alternate method would be to make some pan edge stiffeners like on the later model engine oil pans.

JohnJohn · Mar 16, 2010

I could not get the rubber gaskets to seal with the old pan. Cork is the way to go.

Here is a link to a thread where I made a pan support. With this support the rubber gaskets will also work.
http://www.classicbroncos.com/forums/showthread.php?t=124849

SSDDBRONCO · Mar 18, 2010

what is a CORK???

Viperwolf1 · Mar 18, 2010

SSDDBRONCO said:
what is a CORK???

Very low density soft wood. Typically ground, mixed with a binder and pressed into gasket material. Also used as a stopper to seal bottle necks.

SSDDBRONCO · Mar 18, 2010

are the fel pro gaskets good? I have that one. Any recommendation before i put it on?

Annapolis76EB · Mar 18, 2010

I used the felpro and didn't have any issues with mine. Just torqued to the Haynes manual specs (don't remember what they are off hand) and didn't have any leaks.

JWMcCrary · Mar 18, 2010

How confident are you that it is the pan? I ask because I fought mine for months after a rebuild, even went to a B&M pan with several different gaskets and still had a leak. You could clean it off and watch it and never see a leak, drive it 100 miles and the bottom of the trans would have fluid all over it, never leaked enough to have to add fluid before I would try fixing it again, but enough to get everything wet and smell from hitting the exhaust. My leak was at the servo and was finally found when a transmission shop put it up on a rack and let it run in gear for quite while, seems it only leaked when at speed and had to be caught in the act when everything was still dry.

Thought I would throw this out there since you have tried a few times with no luck.

mango · Mar 18, 2010

Could the bolts be loosening?
Mine need tightening every once in a while.

Thinking of adding lock washers.

How to get tranny pan gasket to not leak?

Blue71

Bronco Guru

Viperwolf1

electron whisperer

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JohnJohn

Bronco Guru

SSDDBRONCO

Bronco Guru

Viperwolf1

electron whisperer

SSDDBRONCO

Bronco Guru

Annapolis76EB

Sr. Member

JWMcCrary

Bronco Guru

mango

Sr. Member

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