Abstract: An auxiliary transmission is provided for a motor vehicle. The auxiliary trans-mission can couple and uncouple input power from the motor to a driveshaft coupled to a differential. The transmission includes a first gearset for coupling the input power to a hydraulic pump and an auxiliary power take-off unit. A second gearset is included for coupling a hydraulic motor to the driveshaft. When power is to be applied to the power take-off unit, the input power is uncoupled from the driveshaft. The hydraulic pump provides pressurized fluid to the hydraulic motor to provide power to the driveshaft. The vehicle's motor can be operated at a constant speed to provide the required power for the power take-off unit whereas the speed of the vehicle can be controlled by controlling the flow of pressurized fluid to the hydraulic motor.