offshore44

Hello all, new to the forum and have an "issue" with the 'Burb.

I have a 1999 Suburban K2500 with all of the heavy duty 4x4 stuff from the factory.

We had some snow the other day, so the wife took the truck to work. She pushed the 'auto 4wheel drive' button. The truck made pea gravel in a blender noises and the drive train locked up solid...as in all forward movement ceased. She put it back into 2 wheel drive and drove it to work and then back home.

I tested the truck out that night and sure enough...it locks up going into 4 wheel drive with horrible noises. Any ideas what broke / is breaking / went wrong? I use 4 wheel drive all year long out in the boonies, and this is the first issue that I have had with it.

Thanks a bunch!