Originally Posted by JJ Glo

Well, like I said, I'm no mechanic and I don't have the equipment necessary to do this so I went to a shop today and they wanted 490 to change the torque converter seal and the oil seal.

Originally Posted by petrock

I’m in the middle of an adventure (to say the least) fixing as many leaks as I can find on my wifey’s car (which also has the 4r70w tranny like your ride). The motor has been out for 2 weeks now as I keep finding more and more things to fix. I just replaced the tranny oil pump o-ring and seal yesterday. I’m waiting on new battery cables before I start putting it back together...

Anyway, with that said, the little rubber thing at the bottom of the bell housing is just a plug. It is not a seal. It is there so you can gain access to the torque converter drain plug (if you choose to drain it during tranny fluid changes). There are two seals inside the bell housing that could leak tranny fluid. The large o-ring around the tranny oil pump (the red arrows in paintballpyro1’s post) and the torque converter/input shaft/tranny pump seal (the black rubber ring at the base of the large splined shaft in paintballpyro1’s post). Both are very easy to replace and very inexpensive parts (less then $10 at rockauto.com for the pair), but they are not easy to get to. You have to either pull the tranny or pull the motor. I went with pulling the motor since I also has an engine oil pan leak and that is easier to replace with the motor out. When you pull the tranny oil pump to replace the o-ring and/or seal (I’d do both), don’t forget to replace the formed gasket behind the pump ($8 at your dealer) or you’ll be tearing it apart again to fix another oil leak.

While your in there, you might as well also replace the rear main seal (also an inexpensive part).

Good luck...