GM Service Manual Online
For 1990-2009 cars only

Wheel Speed Sensor Replacement 2WD (except C3500HD)

Removal Procedure

  1. Raise vehicle.
  2. Remove tire and wheel. Refer to Wheel Removal .
  3. Remove brake caliper. Refer to Brake Caliper Replacement .
  4. Remove the hub and rotor. Refer to Hub and Rotor Assembly Replacement .

  5. Object Number: 403369  Size: SH
  6. Remove wheel speed sensor cable electrical connector.

  7. Object Number: 191508  Size: SH
  8. Remove wheel speed sensor cable mounting clips (4) from frame attachment points.

  9. Object Number: 403369  Size: SH
  10. Remove wheel speed sensor mounting bolts (8) and nuts (15).
  11. Remove two 11 mm splash shield mounting bolts.
  12. Remove wheel speed sensor and splash shield assembly (10).
  13. Remove splash shield gasket.
  14. Clean gasket and knuckle (12) surfaces thoroughly with a dry cloth.

Installation Procedure


    Object Number: 403369  Size: SH
  1. Install splash shield gasket.
  2. Install wheel speed sensor splash shield.
  3. Install two 11 mm splash shield mounting bolts.
  4. Tighten

        • Tighten the splash shield mounting bolts to 16 N·m (12 lb ft)
        • Tighten the speed sensor mounting bolts to 26 N·m (19 lb ft)

    Object Number: 191508  Size: SH
  5. Install harness clips (4), fastening bolts and nuts (5) to the frame attachment points.
  6. Install the hub and rotor. Refer to Hub and Rotor Assembly Replacement .
  7. Install brake caliper. Refer to Brake Caliper Replacement .
  8. Install tire and wheel. Refer to Wheel Removal .

Wheel Speed Sensor Replacement 4WD

Removal Procedure

  1. Raise vehicle.
  2. Remove tire and wheel. Refer to Wheel Removal .
  3. Remove brake caliper. Refer to Brake Caliper Replacement .
  4. Remove the hub and rotor. Refer to Hub and Rotor Assembly Replacement .

  5. Object Number: 191518  Size: SH
  6. Remove wheel speed sensor mounting clip (2) on the control arm.

  7. Object Number: 191521  Size: SH
  8. Remove wheel speed sensor mounting clip (2) on the frame rail.

  9. Object Number: 403371  Size: SH
  10. Remove wheel speed sensor electrical connector (6).
  11. NOTICE: Carefully remove the sensor by pulling it straight out of the bore. DO NOT use a screwdriver, or other device to pry the sensor out of the bore. Prying will cause the sensor body to break off in the bore.

    Important: The wheel speed sensor mounts into a bore that leads to the center of the sealed bearing. Use caution when cleaning or working around the bore. Do not contaminate the lubricant inside the sealed bearing. Failure to do so can lead to premature bearing failure.

  12. Remove wheel speed sensor from hub and bearing assembly.

Installation Procedure

    Important: The new speed sensor will have a new O-ring. Dispose of the old O-ring. Lubricate the new O-ring lightly with bearing grease prior to installation. You may also lubricate the sensor just above and below the new O-ring. Do Not lubricate the bore.


    Object Number: 403371  Size: SH
  1. Install sensor into the hub and bearing assembly (5).
  2. Tighten
    Tighten the sensor mounting bolts to 18 N·m (13 lb ft).

    Important: The new sensor has new mounting clips already installed on the wire. Do not reuse the old clips.


    Object Number: 403371  Size: SH
  3. Install wheel speed sensor electrical connector (6).

  4. Object Number: 191521  Size: SH
  5. Install wheel speed sensor mounting clip (2) to the frame rail.

  6. Object Number: 191518  Size: SH
  7. Install the wheel speed sensor mounting clip (2) to the control arm.
  8. Install the hub and rotor. Refer to Hub and Rotor Assembly Replacement .
  9. Install brake caliper. Refer to Brake Caliper Replacement .
  10. Install tire and wheel. Refer to Wheel Removal .

Wheel Speed Sensor Replacement C 3500HD

Removal Procedure

  1. Raise vehicle.
  2. Remove tire and wheel. Refer to Wheel Removal .
  3. Remove brake caliper. Refer to Brake Caliper Replacement .
  4. Remove the hub and rotor. Refer to Hub and Rotor Assembly Replacement .

  5. Object Number: 405177  Size: SH
  6. Remove the splash shield (1).
  7. Remove the wheel speed sensor wire mounting clip (6) attached to the upper king pin cap.

  8. Object Number: 191534  Size: SH
  9. Wheel speed sensor wire mounting clip (5) attached to the frame rail.

  10. Object Number: 191538  Size: SH
  11. Remove wheel speed sensor cable electrical connector (1).

  12. Object Number: 405174  Size: SH

    Important: It is not necessary to replace the sensor mounting bracket unless there is visible damage or distortion to the mounting bracket.

  13. Remove the wheel speed sensor (3) from the mounting bracket (4).

Installation Procedure

NOTICE: The wheel speed sensor used on the C 3500HD 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 adjust the front wheel speed sensor.


    Object Number: 405174  Size: SH
  1. Install the wheel speed sensor (3) to the mounting bracket (4).
  2. Install wheel speed sensor to bracket mounting nuts (5).
  3. Run down the nuts but do not torque. The wheel speed sensor must remain loose and move along the slots in the bracket.

  4. Object Number: 416811  Size: SH
  5. Place the front hub and rotor assembly on a flat surface with the tone wheel facing up. Take care not to damage the wheel studs.
  6. Mark the position of the rotor relative to the hub so the rotor can be installed in the same position later.
  7. Remove bolts (22) attaching the rotor (21) to the hub (14).
  8. Remove the rotor from the hub.
  9. Install the bearing seal (12) and inner bearing (20).
  10. Install hub and tone wheel assembly (14) on the knuckle spindle (3), taking care not to damage the wheel speed sensor with the tone ring.
  11. Install the hub outer bearing (15), washer (16) and wheel bearing nut (19).
  12. Tighten
    Wheel bearing nut (19) to 16 N·m(12 lb. ft.) while rotating the hub (14) in either direction to ensure proper centering.

  13. Do not back off the wheel bearing nut.
  14. NOTICE: 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 result in the correct air gap.


    Object Number: 407391  Size: SH
  15. Insert flexible shim stock or equivalent between the tone wheel (1) and the wheel speed sensor (4).
  16. The thickness of the shim stock must be 1.5 mm (0.060 in.). The length and width of the shim stock must be sufficient enough 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 speed sensor.
  17. Press the wheel speed sensor firmly against the shim stock and tone wheel.

  18. Object Number: 405174  Size: SH

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  19. Use the following procedure for tightening the WSS nuts
  20. Tighten

    1. Tighten the left hand lower attaching nut to 13 N·m (10 lb. ft.).
    2. Tighten the left hand upper attaching nut to 13 N·m (10 lb. ft.).
    3. Tighten the right hand upper attaching nut to 13 N·m (10 lb. ft.).
    4. Tighten the right hand lower attaching nut to 13 N·m (10 lb. ft.) while holding the wheel speed sensor against the shim stock.

    Object Number: 407391  Size: SH
  21. Remove the shim stock from between the tone wheel (1) and the wheel speed sensor (4).
  22. Inspect that the tone wheel does not contact the wheel speed sensor when the hub and tone wheel are rotated. Readjust if necessary.

  23. Object Number: 416811  Size: SH
  24. Install the splash shield (8) to the anchor plate (9).

  25. Object Number: 405177  Size: SH
  26. Take care to route the wheel speed sensor wire (4) through the opening in the splash shield (1) near the center mounting hole.

  27. Object Number: 416811  Size: SH
  28. Install three splash shield mounting bolts.
  29. Tighten
    Tighten bolts to 17 N·m (13 lb. ft.)


    Object Number: 405177  Size: SH
  30. Route the wheel speed sensor wire (4) between the splash shield (1) and the knuckle.
  31. Install the wheel speed sensor mounting clip (6) to the upper king pin cap.
  32. Tighten
    Tighten the bolt (2) to 17N·m (13 lb. ft.).


    Object Number: 191534  Size: SH
  33. Install the wheel speed sensor mounting clip (5) to the inside frame rail.
  34. Tighten
    Tighten the bolt (6) to 17N·m (13 lb. ft.).


    Object Number: 191538  Size: SH
  35. Connect the wheel speed sensor cable electrical connector (1).

  36. Object Number: 416811  Size: SH
  37. Remove wheel hub and tone wheel assembly (14) from the steering knuckle (3).
  38. Important: Take care to line up reference position marks.

  39. Install hub rotor (29) to wheel hub (22).
  40. Install rotor to hub attaching bolts.
  41. Tighten
    Tighten bolts (22) to 237 N·m (175 lb. ft.).

  42. Install the hub (14) and rotor (21). Refer to Hub and Rotor Assembly Replacement .
  43. Install brake caliper (7). Refer to Brake Caliper Replacement .
  44. Install tire and wheel. Refer to Wheel Installation .