R&R Transfer case and now the selector switch in the vehicle is stuck in 4low.

One option to try is to remove the "shift motor" and see if it works independently of transfer case. If it does look for binding in transfer case.

Also I should have mentioned to make sure the shift motor and the transfer case are in same position.

I swaped out motors with the other transfer case and now it shifts just fine. It turns out that my front differential is toast and it was making all of the noise all along but sounded like it was coming from the t-case. I guess my diagnoses was not so good. I really wish I had brought it to a shop with a lift instead of putting on jack stands and trying to diagnose it by myself. Have you ever replaced a front differential on that type on vehicle?

Best advice here is to get yourself a Haynes book for your vehicle. They do a nice job of explaining major repair issues. I have changed out front ends many times on various vehicles it's a lot of work, but not very difficult. At least you now have a spare transfer case...........

Thanks for the advice, you have been very helpful.

I Have a 2006 cm envoy it keeps switching from 4hi 2 wheel drive can I unhook the 4 wheel drive to get it home