I'm having a recurring problem with my truck, the AT fluid keeps going into my transfer case. I've replaced the input seal on the transfer case several times, but I keep having the problem. Could anything else be causing the problem?

 

The input shaft seal should be keeping fluid in the transfer case, not keeping fluid out of it. It sounds like you may have an issue with the output seal of the transmission.

Red

 

The input seal on the transfer case is double lip seal that is also the rear seal for the transmission.