Procedures

TONE WHEEL INSPECTION

Tone wheels can cause erratic wheel speed sensor signals. Inspect tone wheels for the following possible causes.

- missing, chipped, or broken teeth
- contact with the wheel speed sensor
- wheel speed sensor to tone wheel alignment
- wheel speed sensor to tone wheel clearance
- excessive tone wheel runout
- tone wheel loose on its mounting surface

Rear tone wheels are pressed onto their mounting surfaces and should not rotate independently from the mounting surface.

If a front tone wheel is found to need replacement, the tone wheel can be replaced as a separate component. Tone Ring - Removal

If a rear tone wheel is found to need replacement, the axle shaft must be serviced. No attempt should be made to replace just the tone wheel. Half Shaft - Removal

Check the gap between the speed sensor head and the tone wheel to ensure it is within specifications. Brakes - Specifications

Excessive wheel speed sensor runout can cause erratic wheel speed sensor signals. For the maximum allowed tone wheel runout specification, Brakes - Specifications. If front tone wheel runout is excessive, determine if it is caused by a defect in the tone wheel or hub and bearing. If rear tone wheel runout is excessive, determine if it is caused by a defect in the axle shaft assembly or hub and bearing. Replace as necessary.