i have a buddy of mine with a 96 ext cab 4x4, today he tried putting it in 4 hi and the truck made a loud noise and then no response, i looked at the truck and the front drive shaft with the truck in gear and the 4x lever in 4 hi or low will move freely, the rear shaft is not moving freely however with the truck in gear and in 2hi the truck stiill won't move, my question is, is this the transfere case or the transmission, the motor runs good,