Originally Posted by Possum 6991

If the seal between your transmission & transfer case goes bad, it will let transmission fluid go into your transfer case and will overfill your transfer case. If the vacuum switch on top of your transfer case goes bad it will allow the transmission fluid to be sucked into your vacuum lines which operate the 4WD actuator & HVAC controls on your dash. If this happens you should replace all of the vacuum lines. This does not seem to that rare of an issue. I just replaced all of the vacuum lines in the engine compartment, vacuum switch & seal because of this problem. Hopefully I won't have to replace the vacuum line inside the dash.

Originally Posted by princered72

I myself will also be double checking the fluid level on the stick just to make sure, but how do you know it was the vacuum switch. I check the transfer case and nothing came out. Can you smell it? Does some of the HVAC not work?