I just re-rigged this boat with TRS assemblies and everything is new, all gaskets and seals.

I have gear oil leaking on my inner transom on both assemblies. Bellows are brand new and when I pull the drives they are dry, yet I still have gear coming into my bilge.

Found a similar thread with no solution though:

http://www.offshoreonly.com/forums/g...l-housing.html

It talks of that seal where the nipple for reservoir goes, but even if that's bad, it wont cause a leak inside from what I can see (the hose exits the housing and goes through the inner transom so you would see a leak earlier).

Someone must have had this problem!

The only place gear oil could leak from inside the boat is the hose from the reservoir to transom housing or the vent on top of the reservoir or the gasket on the cover plate on front of the reservoir with the 8 allen head bolts. You can see these 3 places in the pic that you linked.

That seal they speak of would leak outside but it probably never would because the gasket between the drive and bell housing seals that also.

Thats what I thought about the outside seal too! (that it would leak on the outside).

Its very hard to pinpoint where its leaking since its so tight back there now and I can barely see under the transmission output shaft.
I have a feeling its the little tube...possibly where it goes through the assembly or the hose where it comes in.

when i take off my trs drives i inspect the rubber oil lines. better to replace them while they are off then fully assembled cheap insurance

The hose that runs from the overflow reservoir to the transom assembly get old, hard and dry out. Could be cracked and leaking.

Whenever I'm chasing an odd leak I wipe everything down and then stuff paper towels everywhere I think it might be leaking, helps to at least get in the ballpark.