Yiks that looks like it is right on top of the transmount. I guess I could feel for seepage up there but I would not know how to teplace that seal if indeed it is leaking.
Seriously? Two nuts in the center of the crossmember hold the transmission mount. 4 bolts hold the crossmember in. Put a jack under the transmission, remove the aforementioned fasteners, remove the crossmember, then remove the two bolts that hold the transmission mount to the transmission then you are staring at the two phillips screws that hold the plat on. Remove those, remove the plate and replace the seal. reassemble in reverse order. Yikes?
