I was backing up a hill with a trailer and started to spin. Put in 4H could only hear metal on metal noises in the front end. Front tires would not spin. Tried 4L got the same results.
Unhooked trailer got on level ground and it sounded like 4H and 4L were working again. Going to chain to a tree to see if I can get the front tires to spin.
Anybody got any idea on whats going wrong here.
Make matters worse there were three chevy guys there. I'll never hear the end of this.

 

Sounds like an IWE wasn't engaging. You mention that you've had 4x4 problems in the past. What happened then? Any chance it was the common electrical problem causing the IWEs to engage going down the road? Maybe you shredded your IWEs....

 

What he said