A friend has a 1998 Chevy Tahoe 4X4 and I have a few loose ends to wrap up on it after the LIM gaskets I did this past weekend. It uses manual 4X4 and not the pushbutton system in the newer GM trucks. I don't know if the transfer case was serviced, but I ran the VIN through a VIN/RPO decoded and it says it uses a New Process 241 transfer case and I found out it uses AutoTrak II fluid. Is there a substitute for this GM-dealer only fluid - I wouldn't mind the dealer-only stuff but the nearest GM dealers are 30 miles away in any direction.