2004 Jeep Grand Cherokee Owner's Manual - Page 194

194 STARTING AND OPERATING Quadra-Drive System - If Equipped The optional Quadra-Drive System features three torque transfer couplings. The couplings include VariLok front and rear axles and Quadra-Trac II transfer case. The optional Vari-Lok axles are fully automatic and require no driver input to operate. Under normal driving conditions the units function as standard axles balancing torque evenly between left and right wheels. With a traction difference between left and right wheels the coupling will sense a speed difference. As one wheel begins to spin faster than the other, torque will automatically transfer from the wheel that has less traction to the wheel that has traction. While the transfer case and axle couplings differ in design, their operation is similar. Follow the Quadra-Trac II transfer case shifting information, preceding this section, for shifting this system. VARI-LOK FRONT AND REAR AXLES - IF EQUIPPED The optional Vari-Lok axle is fully automatic and requires no driver input to operate. Under normal driving conditions the unit functions as a standard axle balancing torque evenly between left and right wheels. With a traction difference between left and right wheels the coupling will sense a speed difference. As one wheel begins to spin faster than the other, torque will automatically transfer from the wheel that has less traction to the wheel that has traction. PARKING BRAKE To set the parking brake, pull the lever up as firmly as possible. When the parking brake is applied with the ignition ON, the "Brake Warning Light" in the instrument cluster will light.