TH350 Pan Gasket
Thread Starter
Burning Brakes
Joined: Nov 2005
Posts: 832
Likes: 1
From: Breckenridge Colorado
TH350 Pan Gasket
Are all pan gaskets for a TH350 the same? I need to replace the gasket in the transmission pan as it is leaking somewhat bad (3 drops per hour). The gasket used looks to be a thin cork gasket. I hear about the metal ones all the time and I think they are generally preferred and better at preventing leaks. Should I just ask NAPA for a metal pan gasket for a TH350...or is there more I need to look at before I get the gasket.
Race Director
Joined: Sep 2002
Posts: 10,362
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From: San Diego - Deep Within The State of CONFUSION!
Originally Posted by MartyW
Are all pan gaskets for a TH350 the same? I need to replace the gasket in the transmission pan as it is leaking somewhat bad (3 drops per hour). The gasket used looks to be a thin cork gasket. I hear about the metal ones all the time and I think they are generally preferred and better at preventing leaks. Should I just ask NAPA for a metal pan gasket for a TH350...or is there more I need to look at before I get the gasket.
If you clean the gasket area on the pan well enough, and the pan is flat, it won't leak when properly torqued.
Do NOT fill the trans to the full mark when you refill it. Make it about a quart or so low, then let the system warm up before topping it off. Transmission fluid expands a lot when hot, so if you top it off with the system cold, you will be overfilling it.
Thread Starter
Burning Brakes
Joined: Nov 2005
Posts: 832
Likes: 1
From: Breckenridge Colorado
I did nothing to the pan when I got it back from the rebuilt about two weeks ago. It was not shifting right and the mechanic said to add about 1/2 quart to a quart of fluid. I did and a few days later noticed leaking on my garage floor along with the transmission vent plug. I looked under the car and it was leaking from the back of the pan and looked like the gasket was leaking. I checked the bolts and the back ones were looser than the front one so I tightened them up just a bit more. It is still leaking about 3-4 drips per hour. I am not sure if this is because it was overfilled or the gasket never properly sealed. It is almost impossible to read the level properly from the dip stick as it is soo clear it is hard to tell. Was figuring that I would have to drain and remove the pan and put ina new gasket and fill back up to the right level. Wish I could just give it to the shop who did the rebuild but its about 100 miles away and I can't get it there while they are open.
