truck runs fine out of 4x4 had the front differential rebuilt and the transfer case replaced, and new tires put on it, but nothing has worked so far. when using 4x4 makes a loud whining noise at all times. when turning too far right or left will bind and make the tires skip on the pavement. let me know if you know anything this is my mother's truck, and she has had no luck with mechanics since moving to Minnesota. my personal guess is that the mechanic shop didn't build the diff correctly. not sure of any other reasons tires would only skip around in 4x4.