300SDL transmission leaking at driver side here

[SDLCrazier]

hello friends, i have found out that transmission on my 86 300SDL is leaking from driver side circular cover (dunno what it's been called but there must be an o-ring inside hardened - just like B2 on the other side. See arrow pointed area in the photo - found this pic on web for illustration here only). My question - can the o-ring be replaced while tranny is still in place?

Thanks for inputs.

[LNGfish]

The photo isn't opening for me. If it is the Greem Modulator thing then the oring can be changed with transmission in place. my car is a 1982 300SD

[SDLCrazier]

Thanks LNG. It's not the green Modulator but the big one toward the back. You can click on this link to view the pic: http://i56.tinypic.com/m7gww7.png. The position is kinda very tight, not sure I'll need to lower the whole thing.

[BoiseBenz]

That's the governor cover. Easiest to drop the crossmember and rear of trans. Push cover in a bit, extract steel lock ring, pull cover out. Chip out old seal, lube and install new seal. assembly reverse....

[SDLCrazier]

Great to know BoiseBenz. That is exactly what I was looking for. As only I don't need to drop the whole tranny, I would be happy to do the rest of it. Have a great weekend!!