Mod75

Leaky trans gasket time to change it, 75 turbo 400, B&M shift kit and B&M Deep pan.
Cork or rubber ? I think it has cork on it now.
Manual says 7 1/2 pints trans fluid = my 6 quarts plus 2 quarts for the deep pan = 8 quarts of fluid.
Going with a new filter and new o rings for the filter pickup tube.

Main question, is Dexron II still available ? Is Dexron III replacing the II ? Do not want synthetic.
Will be farming this project out this time.

4-vettes

Easy!
Lose the fun sucker and put in a real transmission.
With a third pedal!
Problem solved!

HeadsU.P.

If you go with a cork gasket, Permatex makes a sealant specifically for the pan and is ATF proof. Not all RTVs are.
Had a hard time finding the sealant locally but did find it on EBay in the usual squeeze tube. Permatex Automatic Trans RTV.

In the process of switching from cork to silicone gasket, one of these days, so I have no opinion yet of which is better.

As for ATF, I get gallon jugs and Qts from Summit of the B&M products. It promotes firm shifts. Not everyone enjoys that, however.

IDK if good ol' Walmart still has Dexron II or not. I would think that Advance, AutoZone or O Reileys would. $$$

kansas123

So if you use a cork gasket, you also have to use this Permatex sealant? Thanks

Peterbuilt

HeadsU.P.

No. Some use Permatex Black. Then wonder why the pan leaks.
Lets not forget that ATF is a cleansing agent. (Unlike oil gaskets that work fine with Permatex Black).

Permatex knows what's best for each situation. But maybe difficult to find the proper product locally.

Eric P

Dex/Merc and dry cork gasket with no sealant for GM , Ford and Mopar on 3 speed auto is how I do it, after hundreds and hundreds of transmission overhauls it always seems to work best for me plus you can still remove the pan to make adjustments if needed and still be able to reuse the gasket without fear of leakage

augiedoggy

Its my understanding that dex 3 would be the replacement for dex 2 and would not only meet the same standards but surpass them. That the way it works with Mopar anyway and ATF+3 vs ATF+4.

kansas123

Thanks. What I really meant to ask is can you use just the cork gasket alone.

GTR1999

We ran FORD trans fluid over the GM stuff. Not sure that still applies but it was one of "the" tranny tricks used. I have it still in my TH400, no issues but I only drive the car, no racing.

HeadsU.P.

If you are going to use cork then I recommend the Permatex Trans RTV.
If you use a silicone (blue) reuseable gasket, supposedly they do not require any RTV sealant.

When I get to my aluminum deep pan project someday, I plan to use the special RTV and glue my blue gasket to the pan. Clamp it on the workbench, let it set all night.
May apply sealant to both sides of gasket. Not sure yet.

Unlike oil pans, the trans pan is flooded. The ATF level is well above the pan gasket parting line when the vehicle is parked, flooded. That's why the dip-stick tube leaks during prolonged storage.
Having said that, I am not convinced a silicone gasket should be installed dry.

And I would never install ANY cork gasket dry, whether its valve cover, oil pan or trans pan.