Transfer case/tranny seal help!

[HMH2SUT]

I wasnt under the assumption that the seal on the tail of the Tranny could fail and leak into the TCase they are connected thru tail shaft adapter. If the rear seal fails the fluid can work itself into the Tcase mixing the 2 kinds of atf. I have read of this problem on another forum years ago Ill try to find it again.

I am the only one who services my truck I wont let anyone else touch it. I have changed the Tcase fluid 3 times prior to this I try to do it every 30k or less. I realize atf fluid expands when heated. Its always been changed cold as it was today the truck wasnt driven for 3 days prior to starting the work.
I decided to drop the Tcase and Investigate but It wasnt needed, in preping to drop the Tcase I drained 3.5 quarts (supposed to be 2 quarts) of fluid from the Tcase into a clear container instead of my grimy black bucket this time and realized I had water contamination... I checked the front diff same thing water... Changed fluid in both everything seems to be working fine now. Im guessing this might have something to do with my bad habit of driving into the lake next door, I had water come over the door in the window last time hahaha I wont be happy till im pulled it out dead flooded with my back hoe!!! My SUT is USED and ABUSED!!! thanks for the quick reply