Wheel Speed Sensor: Testing and Inspection

FRONT SENSOR AIR GAP
Front sensor air gap is fixed and not adjustable. Only rear sensor air gap is adjustable.

Although front air gap is not adjustable, it can be checked if diagnosis indicates this is necessary. Front air gap should be 0.40 to 1.3 mm (0.0157 to 0.051 inch). If gap is incorrect, the sensor is either loose, or damaged.

REAR SENSOR AIR GAP
A rear sensor air gap adjustment is only needed when reinstalling an original sensor. Replacement sensors have an air gap spacer attached to the sensor pickup face. The spacer establishes correct air gap when pressed against the tone ring during installation. As the tone ring rotates, it peels the spacer off the sensor to create the required air gap. Rear sensor air gap is 0.28 to 1.5 mm (0.011 to 0.059 inch).