I have noticed a few times at the dunes my truck won't spin the tires in fourwheel drive in reverse? Is there a rev limiter or something that would cause this? My truck is a 2000 Sierra 1500. It got me stuck today. A tiny hill going to slow the wife and two girls with me. I made it right to the top started to dig put it in reverse to back down and couldn't get any momentum going. The second I hit the bottom I was done. Never really been a issue before don't spend a lot of time reversing in the dunes. The thing that really makes me mad is have pulled a quad hauler with four quads over that hill before with out a problem. My wife does not like the whole offroading deal since one of her college roomies died in a rollover offroading if she does come we have to go slow.