Rear Antilock Braking System

F-150 through F-350 series and Bronco vehicles use the Rear Antilock Braking System (RABS). Axles in vehicles equipped with the RABS contain a sensor and excitor ring mounted in the carrier. The system features a multi-tooth excitor ring that is pressed on the differential case behind the ring gear. If the excitor ring is removed, it must be discarded and replaced with a new one. The excitor ring works in conjunction with an electronic speed sensor. This sensor is retained in a bore at the top of the carrier housing and fastened by one bolt. There is a space provided between the ring gear and excitor ring for measuring the ring gear backface runout.