So I have been battling a leak from my transmission as the car was sitting in storage. A decent size wet spot developed on the transmission. When I got under the car, I saw the leak was primarily from the rear driver side corner of the oil pain, possible from the fill plug, and a small amount from the selector shaft seal.

For context:
- Currently at 119K miles
- GM A5S390R
- New transmission filter, gasket and fluid at ~88k miles (I think there was already some leaking as the oil pain was pretty caked in oily residue.
- Developed leaking again around 114k miles, so changed gasket again at 116k miles
- There was still leak, narrowed it down to the drain plug and selector shaft seal --> at 117k changed drain plug (fixed) and placed selector shaft seal o-ring and washer (theres a DIY somewhere).


Now I am still getting an annoying leak despite 2 gasket changes. The selector shaft seal leak is something I may have to keep troubleshooting if it continues, but what do I do about the gasket? RTV is not required here per the Bentley manual, but should just do it anyway? Should I torque it beyond the spec?

Appreciate any help guys.