A wheel speed measurement system for a drive axle is provided within a differential assembly. The system includes a differential side bearing adjustment ring configured for adjusting the position of a differential carrier bearing assembly. A tone ring is provided having an inner bore to accommodate a coaxial axle shaft. A retainer ring member is snap-fit between the differential side bearing adjustment ring and the tone ring, permitting relative rotation of the tone ring. Sensors are provided in sensor mounts integrally formed on an exterior of a differential assembly housing.