Snowing this morning and transfer case won't shift into 4 high. 4 low works but can't move lever back. Any thoughts? I looked under the truck and didn't see anything wrong.

 

Same thing happened tonight with my '92. Don't know what the hell is wrong. Had to leave her parked at Wal-Mart because now she won't shift out of 4L at all. Really rough trying to shift into anything else, and all I get is that awful grinding. Let me know if you solved the problem with your yet.

 

This is pretty obvious but I gotta ask - Did you try backing up in a straight line while trying to get it to shift? That will usually get rid of drivetrain 'wind-up' ..... sometimes when you pull forward again it will shift.