A drive system for a hydraulically driven vehicle which includes bidirectional hydraulic motors. Two front hydraulic motors are in parallel as are two rear hydraulic motors. One of the front hydraulic motors is in series with the rear hydraulic motor on the same side of the vehicle. The other front hydraulic motors is in series with the rear hydraulic motor in the other side of the vehicle. The rear hydraulic motors include mechanical brakes in combination. The front hydraulic motors are mounted as part of the spindles which pivot about king pins.