Hello, my transmission on my 190E leaks on the passenger side where a big round metal seal is located, toward the front. This seal will move in and out and is attached with a metal locking ring. What is supposed to keep fluid from leaking out, an o-ring, a gasket, or what? At first I thought it was the pan gasket but it wasn't. I do all my own work but the transmission is foreign to me. Please help. Thanks.

Yes there is an o-ring. Would be easy to replace but there is a VERY strong spring behind the front round cover.
Mike

Mike, I have an old transmission that I practiced on and the spring was strong just like you said. But I can push the outer metal cover in with my finger on the tranny that is leaking, it is just that easy. Does this indicate more problems than just an o-ring? Also, is the o-ring behind the round metal cover or in front of it?
thanks for your help!!!!!!!!!!

Look here for picture of the spring and more info:
B1 Piston Leak
The orange colored o-ring is in the groove in the bore around the cover.
Mike

Thanks Mike, now how can I get a new o-ring? Where would I get the information on the transmission in order to make sure I get the proper o-ring? Like I said before, I'm lost on transmissions. Is it possible to take the old one to the parts store and match it with a replacement? Thanks again

Mike, I was incorrect about the leak coming from the front of tranny. It was leaking from the large round metal cap towards the rear on the passenger side. I removed the cover and replace the orange o-ring and bingo, the leak stopped. Thanks for all you help. Oh yeah, I did it all without dropping the transmission at all. 190e2