Trans fluid leak after heavy hauling
99 F350 4WD dually automatic 100K miles, all stock for the most part. Just returned from trip about 5 hours on the road, outside temp around 90, several mountain passes 2-3000 ft. Hauling heavy camper and towing boat. Truck ran fine, has been no transmission slip or shifting problems. Upon stopping at home and backing up noticed about a half cup of transmission fluid leak onto the road and trail back into driveway where about another half cup leaked out. The leak stopped and it does not leak now when truck is running. It appears to be leaking from a cover attached to the bottom of the bell housing. The cover looks like it has a small hole in the bottom.
My mechanical knowledge is limited and I have read several posts referring to the torque converter and front seal. My assumption is that the leak is related to overheating. My question is whether there is some kind of "vent" that the fluid would leak out of when it overheats? Or am I just being too hopeful and there is a seal that needs replacing? If so, specifically what seal are we most likely talking about? Thanks for you help. Sorry if this is not correct forum, first post.