I have a tranny leak behind the NSS switch. I removed the NSS switch and found a circle shaped disc about 1" in diameter ( B2 reaction piston ??). I think ATF is leaking from the seam. I was told there is a o-ring inside the B2 reaction piston. The leak is not coming from the shift shaft lever.

How can I fix it? Do I need to drop the transmission? I seem to have read that it can be fixed with the tranny in place.

Any ideas?

Thanks.