hey Step i have a 94 Tahoe Diesel 4x4 if yours is a 4x4 you'll need one of these in time. This replaces the keeper ring on the tail shaft in the transfer case. If your truck starts acting like it is grinding in 2WD but works fine in 4WD then this has broken. Cheap easy insurance.
http://www.drivetrain.com/gillies/Tcasesaver.html
