My 2001 Zr2 trans is leaking into the transfer case. I've had the vehicle for 3 years now and the problem was just noticed recently. It seems to be getting worse rapidly. I have been told this is a common malfunction. How tough is it to pull these units and replace the seals? Everything seems to run OK other than the leaks. Should I attempt this or take it/them to a shop? Thanks.

P.S. As I continue to read about this I am now wondering if this is caused by the rear trans seal or the front transfer case seal?