The wheel speed sensor (WSS) determines the speed, or the rate of rotation in the rotors, of the wheels while the vehicle is running. The Avalanche wheel speed sensor works as part of the anti-lock brake system, which uses information from the wheel speed sensor to stop the vehicle correctly.
Use a jack to raise and support the truck.
Take off the tire and the wheel, as well as the brake rotor.
Remove the WSS cable mounting clips. You'll find one on the knuckle, one on the upper control arm and one on the frame attachment point. With the clips removed, you should be able to detach the WSS cable electrical connector.
Position a wrench or a socket on the mounting bolt for the Avalanche wheel speed sensor. Loosen and detach the bolt.
Pull straight out on the wheel speed sensor. You need to separate the part from the bore in the hub/bearing assembly.
Cover the WSS bore and clean the area.
Lubricate the O-ring and hub surfaces with a wheel bearing lubricant. Insert the new Avalanche wheel speed sensor and reassemble the components you removed. If you have a torque wrench, tighten the WSS mounting bolt to 13 foot pounds (18 Nm).
