Review on 🔧 Dorman 600-903 Transfer Case Shift Motor for Compatible Car Models by Roy Ramos

Problem: Trailblazer stuck at 4low. TCCM and front-wheel drive were fine. I looked at the transfer case motor. Disconnected the old transfer case motor but left it connected. I set it to 2hi and saw that the transfer case motor wasn't spinning. Disassembled it and found the bolts holding the very first 4 cogs/gears were broken - hence no rotation. Solution: Replace the transfer case motor: start the engine, put it in neutral, set the parking brake, rotate the splines to match the new gear. Position the vise (clockwise in my case), installed the engine, put the car back in park, shut the engine off, and then powered the transfer case motor. Leave the switch in the 2hi position before starting the engine. No more 4wd errors and the Trailblazer alternated between 2hi, A4wd, 4hi as usual.