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. Brake Specifications

Excessive wheel speed sensor runout can cause erratic wheel speed sensor signals. For the maximum allowed tone wheel runout specification, Brake 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.