Front Sensor Replacement

Wheel Speed Sensor (HD Models):

WSS Harness Routing (HD Models):

WSS Harness Routing (C 3500HD):

Remove or Disconnect
1. Tire and wheel.
2. Brake Caliper.
3. Hub and rotor assembly.
4. Splash shield.
5. Wheel speed sensor wire mounting clip attached to upper king pin cap.
6. Wheel speed sensor wire mounting clip attached to frame rail.
7. Wheel speed sensor electrical connector.
8. Wheel speed sensor to bracket mounting nuts and bolts.
^ It is not necessary to remove the wheel speed sensor mounting bracket unless the bracket is damaged.
9. Wheel speed sensor from mounting bracket.
^ It is not necessary to replace the sensor mounting bracket unless there is visible damage or distortion to the mounting bracket.

NOTE: The wheel speed sensor used on the HD models is adjustable by means of slots provided In the mounting bracket. The sensor must be properly adjusted in order to provide the correct air gap between the wheel speed sensor and the tone wheel. If the sensor is not properly adjusted, the tone wheel may hit the wheel speed sensor or the output from the wheel speed sensor may be low, missing, or erratic. Follow the procedure outlined below to properly install and adjust the front wheel speed sensor.

Install or Connect
1. Wheel speed sensor to mounting bracket.
2. Wheel speed sensor to bracket mounting nuts and bolts.
^ Run down nuts but do not torque. The wheel speed sensor must remain loose and move along the slots in the bracket.
3. Place the front hub and rotor assembly on a surface with the tone wheel facing up. Take care not to damage the wheel studs.
4. Mark the position of the rotor relative to the hub so the rotor can be reinstalled in the same position later.

Remove or Disconnect
1. Bolts attaching the rotor to the hub.
2. Rotor from the hub.

Install or Connect
1. Hub and tone wheel assembly on the knuckle spindle.
2. Outer bearing, washer and spindle nut.
^ Tighten spindle nut to 12 ft. lbs. while rotating the hub in either direction. Do not back off the nut.
3. Insert flexible shim stock or equivalent between the tone wheel and the wheel speed sensor.

NOTE: The thickness of the shim stock must be 1.25 mm (0.050 inch). The length and width of the shim stock must be sufficient to cover the face of the wheel speed sensor. If shim stock is not available, regular notebook or writing paper can be used provided the specified thickness is inserted between the tone wheel and the wheel sensor.

NOTE: DO NOT use a rigid feeler gauge or a wire spark plug gap gauge to set the wheel speed sensor to tone wheel air gap as these tools will not provide the correct air gap.

4. Press wheel speed sensor firmly against the shim stock and the tone wheel.
^ Tighten as follows:
a. The lefthand lower attaching nut to 13 Nm (10 ft. lbs.).
b. The lefthand upper attaching nut to 13 Nm (10 ft. lbs.).
c. The righthand upper attaching nut to 13 Nm (10 ft. lbs.).
d. The righthand lower attaching nut to 13 Nm (10 ft. lbs.) while holding the wheel speed sensor against the shim stock.
5. Remove the shim stock from between the tone wheel and the wheel speed sensor. Ensure the tone wheel does not contact the wheel speed sensor when the hub and tone wheel are rotated.

Install or Connect
1. The splash shield to the front anchor plate.
^ Take care to route the wheel speed sensor wire through the opening in the splash shield near the center mounting hole.
^ Tighten Bolts to 17 Nm (13 lb. ft.).
2. Route the wheel speed sensor wire between the splash shield and the knuckle.
3. The wheel speed sensor mounting clip to the upper king pin cap.
^ Tighten bolt to 17 Nm (13 lb. ft.).
4. Electrical connectors.

Install or Connect
1. Front wheel hub and tone wheel assembly to spindle.
2. Rotor to front wheel hub.
^ Take care to Line up reference position marks.
3. Bolts.
^ Tighten bolts to 237 Nm (175 ft. lbs.)
4. Front hub and rotor assembly.
5. Caliper assembly.
6. Tire and wheel.