Transfercase over pressuring from tranny
 

Well I took the blazer for a drive to clean her out:D .
when I got back home I started to get a puddle underneath her..
I looked all over at everything and saw the vent tube wet on my transfercase..
When I opened up the fill hole fluid just pressured right out and my tranny was at the add mark..My tranny doesn't leak..

Does this sound like the seal went bad..
Thats my best guess, so I dropped it and took a look at the seal. It looks ok but now thats its down I think I still will replace it..
I probably just answered my own question.
Oh well

Yup, gotta be the seal. Mine went bad once - I didn't notice any pressure in the t-case, but the tranny kept losing fluid (with no visible leaks) and the t-case kept filling up with tranny fluid!

check and be sure the vent tube is not pluged on the tranny

trans adapter
 

Should be bad seal(s) in adapter between trans and transfer case. I had this happen and had smoke screen behind me from fluid burning off exhaust. Whole underside of truck was coverd with fluid. had shop put new seals in adapter and all better.

Be sure to use an genuine gm seal because several years ago I had the same problem and used aftermarket seals they would hold only for about a month then leak again solved the problem by going with genuine gm!