Gasket sealer

425/409ER

Well Known Member
Hi everyone. Just trying to gather up as many opinions as possible re. using a gasket sealer on a TH400 transmission pan. Yes? No? Just seal it to the pan? Both sides? Thanks as usual, Carmine.

What kid of pan? steel or aluminum?. I just found a real good gasket for my aluminum pan that has leaked since I put it on and now it does not leak for the first time. If it's a GM steel pan then get the gasket from the dealer. I used them all the time with no leaks.
 

Carmine

Well Known Member
Supporting Member 10
What kid of pan? steel or aluminum?. I just found a real good gasket for my aluminum pan that has leaked since I put it on and now it does not leak for the first time. If it's a GM steel pan then get the gasket from the dealer. I used them all the time with no leaks.
An aluminum pan. Thanks.
 

scott hall

Well Known Member
Supporting Member 2
Russ you wouldn’t want it. It’s a BOP case with an ultra bell. Wouldn’t like right in one of your cool rides.
 

wristpin

Well Known Member
Carmine, get some permatex ultragasket hardening. Put a THINNNNN coat on the pan then align the gasket. Clean transmission bolt holes and bolts with brake clean and q-tips. Use Blue Lok tite on bolts. Align gasket and pan with bolts leaving them loose until they all start. Then barely snug each one going around in a star type pattern. Do final snug of i believe 12 inch pounds. Maybe someone here knows factory torque spec or i can get off my lazy ass and check a book. Use a flat washer but NOT a locking type washer. Wait a day and add fluid then go for a drive.
 

Carmine

Well Known Member
Supporting Member 10
Thanks wristpin. I'm in the process of doing pretty much everything you suggested. Every is clean. The gasket which looks like a quality one for a change, I have sitting on the pan. In the corners I put a very small dab of permatex on the pan, just to hold it in place. The holes line up nicely and it seems to be secure. I never realized the pan bolts are suppose to be torqued. I always just tightened them. Probably too much. From what I read the torque is 12 ft. lbs. and in a criss cross pattern. Probably won't get to this for a few days, Carmine.
 

Carmine

Well Known Member
Supporting Member 10
If you have a aluminium pan the torque may be different that the factory steel pan.
Good idea. Never thought of that. Maybe I'll just snug them for now. I can always give them a little more it needed, Carmine.
 
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