Hey Guys, Its been a while, but I'm finally working to get my Buick back on the road. I am refreshing a TH400, which includes installing a new pan (a Derale cooling pan). Quick question: Are there any tips or tricks I should be aware of when installing this pan (aside from the usual...clean mating surface, torqueing the bolts to spec, gasket sealer, etc)? Are there some gaskets that are preferred? Also, prior to the shop installing the transmission, I'll be replacing the filter and installing a new torque converter, and using new trans cooler lines. Pretty straight forward, but any tips are greatly appreciated. Thanks, Langston
I'm sure George meant to say "Cork" gasket & NOT "Cord" gasket. Hopefully your car doesn't sit too low as the extra depth of the pan can be hazardous to your refresh.
If the pan is aluminum I would go rubber. If it is tin then use cork. A rubber gasket requires more torque than a cork gasket. The tin will usually distort before the proper torque is reached and will leak like a sieve.
https://www.lubelocker.com/collections/transmission-gaskets/products/gm-th400-transmission-llt-g400 This my choice. A little more money but reusable and less prone to leaking.
I just put one of these on my Riv a couple of months ago. I used the gasket that came with the pan and used no gasket sealer or glue. I don't remember the factory torque spec off the top of my head but I think it's 144 in/lbs. I torqued mine to 100 in/lbs as that is where I started to see the gasket pushing out. No issues.
Actually my 99 Grand Prix GT came with GM factory reusable transmission pan gasket and I have taken it off MANY times and never a leak!
Just about ready for fluid & installation. Just ordered new flexible cooling lines. Gonna go with a new mount as well. My car hasn't moved in over 2 years. I'm getting anxious!
Big fan of this gasket: Check out this page from Summit Racing https://www.summitracing.com/parts/mor-93103?rrec=true Jim
