I have a 96 z71 1500, I can drive my truck all day in 2wd. But when I park it at night and wake up the next morning it is in 4x4. It just kicks itself in fourwheel drive after about 5 hours of sitting still. To get it out of four wheel drive you have to drive about 4-5 miles. Park, turn the truck off and back on. And your good to go the rest of the day! I changed the transfer case motor last year. Anyone have and idea of what this could be?!