Last weekend I replaced the transfer case motor (encoder motor). Crossing my fingers I hit the 4Hi button I hear a noise underneath me and no luck it just goes right back to 2HI, tried 4Lo same thing hear a clunk right back to 2Hi. Any ideas on this one. Could I have gotten a bad motor. Tried doing it in park, neutral and driving- which was the worst noise. 99 Blazer

 

have you checked the actuator for vacuum when you switch to 4wd?