04 yukon denali

[dbertram]

So Im an aircraft mechanic and know basically nothing about transmissions. I have an 04 Denali Yukon. I noticed the other day after about two hours on the highway when I stopped there was a LIGHT MIST OF TRANNY fluid on the rear window. the under carriage was damp but not dripping any where. when I got to my destination I crawled under truck and found fluid on left side forward of trans case. above and bolos pan gasket and around shifter mechanism. I checked fluid level and it was good(hot). I drove for another half hour or so and had no leaks. The next day a drove over an hour with no issues. On my way home after another 2 hours on the highway I saw smoke in the rear view. I slowed to 55 or so and smoke stopped. got out and found more fluid in same area(hits driveshaft and slings everywhere including exhaust pipe).I checked fluid and found still well within normal range. I let the truck cool for 10 mins or so and finished the hour drive home with no issues. The truck shifts perfect. and shows no issues. I drove easy and I romped it to try to see if it would slip but no issues. didn't know if anyone had any thoughts. Considered a gasket change, thought it could be converter or a strange buildup of pressure. If anyone has any experience with a similar issue I would appreciate the input before I take it to a shop. Thanks

p.s. wanted to say that its been pretty hot. like high 90's. the trans temp was reading 180 or so on the highway at 75 mph. I didn't think that was that bad. I wasn't towing but the truck had 2 adults 2 kids three days worth of gear in it. but not too heavy