Tone Wheel

INSPECTION
Tone wheels can cause erratic Wheel Speed Sensor (WSS) signals. Inspect tone wheels for the following possible causes:
- missing, chipped, or broken teeth
- contact with the WSS
- WSS to tone wheel alignment
- WSS to tone wheel clearance
- excessive tone wheel runout
- Tone wheel loose on its mounting surface
If a front tone wheel is found to need replacement, the drive shaft must be replaced. No attempt should be made to replace just the tone wheel.
If a rear tone wheel is found to need replacement, the rear hub and bearing must be replaced. No attempt should be made to replace just the tone wheel.
If WSS to tone wheel contact is evident, determine the cause and correct it before replacing the WSS or tone wheel.
Check the gap between the speed sensor head and the tone wheel to ensure it is within specifications.
Excessive tone wheel runout can cause erratic WSS signals. If tone wheel runout is excessive, determine if it is caused by a defect in the driveshaft assembly or hub and bearing. Replace as necessary.
Tone wheels are pressed onto their mounting surfaces and should not rotate independently from the mounting surface. Replacement of the front drive-shaft or rear hub and bearing as necessary.