1977 F100 C-6 Transmission Pan issue

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Jun 27, 2010 | 09:42 PM

77f100guy

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1977 F100 C-6 Transmission Pan issue

I have replaced the filter and gasket(the gasket a number of times) and still I have a leak from the the surface where the pan meets the box. I have tried a number of things and still it leaks. So I decided to buy a new pan, I put it on with a new gasket and still it leaks. I torqued the bolts to 15ftp with a 1/2 drive torque wrench and it seems way too tight, squeezing the gasket out the sides. Due to this issue I can not get my truck to move because of the constantly fluid leakage. Can some one PLEASE help me? I'm about to just take it to a mechanic, but that would defeat the purpose of me having a project. ANYONE HAVE ANY IDEAS, EVER RAN INTO THIS PROBLEM? TIPS OR TRICKS?

Jun 27, 2010 | 10:46 PM

hasteranger

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From: West Virginia

have you tried some form a gasket type stuff? is the mating surface of the transmission square and true (check with a straight edge) and is it clean?

Jun 27, 2010 | 11:43 PM

77f100guy

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Surfaces are clean and square. I use gasket maker one time and it seemed to leave gaps.

Jun 28, 2010 | 07:21 AM

mark a.

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If the leak is comming from the left side maby it's the shifter seal or kickdown O ring seal leaking.

Jun 28, 2010 | 07:46 AM

jim collins

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From: South west Idaho

I had the same trouble and went though the same steps you have on a brand X transmission. Not only did it turned out too be the O ring ,but the front pump seal was bad and it would leak out and follow along the pan edges , making it look like it was the pan.

P.S. , check where your speedometer cable goes in too.

Last edited by jim collins; Jun 28, 2010 at 07:51 AM. Reason: added more

Jun 28, 2010 | 10:14 AM

Joseph69

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Way too tight on the 15ft lbs, maybe 15 inch lbs! If you dont have a torque wrench that will do that use a 1/4 inch drive and just snug the bolts. Too much torque will not only smash the gasket out but also deform the sheet metal of the pan.

Jun 28, 2010 | 10:35 AM

jk080

Transmission Rebuilder

Joined: Jul 2008

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From: North Georgia

Forget the gasket altogether just use silicone, there are alot of transmissions out there that have no gaskets and only assembled with silicone.

You may want to look at your shifter seals, they can leak down on the pan rail and make it look like its the gasket.