An in-axle wheel speed sensor exciter rotor assembly (100) for sensing the rotational speeds of a drive axle ring gear (14/30) and a drive axle differential side gear (48) is provided. The assembly includes a tubular member (102) having teeth (110) for engagement with slots (112) provided on the side gear hub (48a) and carrying a first exciter rotor (116) at the opposite end (114) thereof. A second exciter rotor (118) is axially retained on the tubular member axially adjacent the first exciter rotor and is rotatable relative thereto. The second exciter rotor carries a coupling device (124/128) for engagement with threaded bores (126) provided in the drive axle ring gear/carrier assembly to rotationally couple the second exciter rotor to the ring gear and to axially retain the assembly (100) within the drive axle.