Re: 4 wheel drive slipping - opinions
It's working just fine. When you drive in a straight line, all 4 wheels are rotating at the same speed, and the whole driveline smiles happily.
When you're turning sharply, the rear wheels will "cut the corner".... the front wheels will need to travel farther than the rears. This would be fine and dandy if they were allowed to rotate faster than the rears, but they're not.... the transfer case is locking the front and rear propshafts together, forcing the fronts to rotate the same speed as the rears, so something has to give.
Depending on the load distribution, the available traction at each wheel, and whether or not you have limited slip differentials, one wheel (either front or rear) is going to either spin (a rear) or skid (a front) intermittently. That's what you're feeling.