Coolant in Transfer Case

[Towbarman]

Morning to yall
I have a M1151 with coolant in the transfer case. What would cause this to happen. I only know this issue from my mechanic/ inspector. My thought was to change out the T-Case instead of the transmission or would it best to change both out. Not sure how long the fluid has been in the vehicle and if the vehicle has been driven all this time with this issue. Any help would be appreciated. Thanks from Towbarmani Ark.

 

[DREDnot]

How did he determine this? During fluid change?
If you have the liquid cooled rear diff I believe that the transfer case is also cooled with engine coolant as well. Older models were cooled with transmission fluid. There is a "cooling loop" in the transfer case that has been known to crack internally and leak into the T-case. On the older ATF cooled models its known as the "vampire disease" It would drain the transmission of ATF "blood" and overfill the T-case and fill up the vent system till it showed up as red ATF in the air cleaner housing. If you do a search for the vampire disease you will see the cooling loop that may be your issue as well just with green engine coolant instead.