Looking for help here; 76 3/4 ton, 4X4. When in hi-lock I seem to have 4X4 lock; same in low-lock. However I went to pull a stuck vehicle this afternoon and rear wheels broke free with no power apparently going to the front axle. This was the case in both high and low lock. When I unhooked the vehicle I was trying to pull it seemed as though power returned to front axle. Anyone know what gives, is it possible for "slippage" in the transfer case?? I thought maybe I wasn't completely in high-lock and was pulling shift lever; while tranny in gear, 350 auto btw, and it felt as though I was pulling against spinning gears, did that make sense? Answers anyone?