2001 Z71 Autotrac Help

Anotherws6guy · February 4, 2010

Truck: 2001 Chevy Silverado K1500 z71 ECSB 5.3/4l60e w/autotrac transfer case (NP 236???)

Ok, so yesterday was a rainy day and I was pulling a decently heavy trailer (~5000lb) and every time I would go to make a corner the front wheels would slip a little. So as a safety precaution, I put the truck in Auto 4wd just in case it I lost control I might be able to recover with the front wheels pulling. I came up on a guy going 25mph in a 60. After awhile of following him, I got an opening so I got over and gave it some gas. It spun both back tires (g80) and felt like both fronts. So I got back in behind him until I had a bigger gap to pass him. After the pass everything was going smoothly, I pulled into my ranch (still in auto), down my muddy driveway and parked. I dropped the trailer and went on about my day. Later, I got in my truck and pulled around into the ditch, waiting on my cousin to come out. When I went to leave in noticed a lot of tire spinning when in auto but I just got on it and got out of the ditch. My other cousin started yelling something at me about not being in 4wd. I yelled back that I was in 4wd. Now curious, I pulled onto the road, put my truck in 4hi and powerbraked. Sure enough, back wheels spun and front stayed still. I looked under it and had my cuz do another powerbrake while I watched. Front drive shaft is not spinning. No DTCs and the 4wd lights act completely normal, blinking for a few seconds and then showing engaged. I can here the transfer case shifting and can definitely tell when it is in 4 LO, but still no front drive shaft spin. I can't seem to figure this out. HELP?