hey, Doink
I found a technical service bulletin on a leaking reverse servo cover.
If this is where your leak is coming from you can have this serviced by any profession auto repair shop or by your local dealer. The technical service bulleting is listed under customer interest so it is not a recall and the dealer will not repai nor replace any parts for free.
Have the professional shop look up this bulleting and also have them inspect the whole transmission to locate the leak.
The bulleting number is.. 04-07-30-028A subject 4t65E listed under technical. Reverse servo cover leak.
I hope this solves your problem. If you have any more questions please feel free to write back.
Your next step now is to accept my answer.
Bonuses are always greatly apreciated. Thanks again.
I operate my own Auto repair Shop
ASE certified all cars and Automotive business owner.