Addi-Drive Front Assist is a hydraulic on-demand, all-wheel drive system designed for use on Class 6 through 8 vehicles. Hydraulic motors integrated into the wheel-ends do not require modification of the truck chassis and do not change the cab/chassis height. The system saves about 1,000 pounds compared to mechanical front-wheel drive systems and installs in less than half the time. Addi-Drive Rear Creep Drive is installed on all types and brands ofmechanical transmissions between the input and output shaft to allow vehicles to travel at speeds of 0.5 to 5 miles per hour independent of engine speed. Disengage rear creep and engage mechanical transmission to travel at normal highway speeds. Estimated list price, before installation: $30,000.