Wider and better are the axles on the Grand, with the Dana 30 front and aluminum-cased Dana 44 in the rear. The big difference is the option of new Vari-Lok differentials, front and rear. This speed-sensing torque transfer diff is the U.S. industries' first to be installed in a frontend. Using the same gerotor technology as the Quadra-Trac II transfer case, the Vari-Lok diffs sense the difference in wheel speed, such as when a wheel is slipping. Oil pressure forces the clutches to engage and transmit power to the wheel that has traction, without any driver input from switches, cables, or buttons.