Car reluctor ring

How to detect the ABS tone ring failure

To evaluate the part condition, you have to raise the car with a jack and examine the tone ring, slowly rotating the wheel. Cracks, crushed teeth, rust, loose part attachment to the seating surface, detachment of the magnetic strip show that the part has failed.

You may identify  that the ABS tone ring needs diagnosis by the following symptoms:

• the corresponding indicator lights on the instrument panel;
• the car skids during braking;
• a large effort is required to turn the steering wheel;
• the braking efficiency, especially on wet roads or gravel, has decreased considerably.

Causes of the ABS tone ring failure

The ABS sensor ring is situated under the vehicle bottom and is continuously exposed to dirt, moisture, chemicals. Eventually the strength of the metal from which the part is produced, decreases and the ring can crack. Besides, the component is largely prone to corrosion. As a result of aggressive environment impact, the magnetic strip can peel off in the pulse rings.

Frequent driving on poor-quality surfaced roads may also cause the part damage. The ingress of gravel or hitting an obstacle can cause the ring warping or breakage.

Sometimes the part malfunctions result from errors during installation. In particular, the ring can fracture because of too much force applied to press it on the CV joint (constant velocity joint) or excessive overheating. Careless actions when removing the CV joint boot may result in similar effect.

The ABS tone ring premature disruption can be provoked by faults of other suspension components. For instance, the wheel bearing excessive wear, accompanied by the wheel skewing, leads to reduction of the clearance between the sensor and the ring. Eventually the parts start rubbing against each other and fail.

Replacement of the ABS tone ring

You can perform a new part installation both at a service station and by yourself. The complexity of the work and the replacement procedure are dependent on the part location and the car design. If the vehicle is equipped with a ring integrated into the wheel bearing, it is likely that you will have to replace the whole assembly. If the component is mounted on the CV joint, you will have to open access to the joint outer part. For this, dismantle the wheel, remove the brake caliper, disconnect the shock absorber strut, pull the CV joint out of the hub after unscrewing the related fasteners, and then carefully knock out the ring from the outer race of the assembly. Before installing a new component, the mounting seat must be cleaned from dirt and rust, then greased, and the part itself should be heated to make installation easier.

If you have no relevant experience, it is best to seek assistance from specialists. When replacing the part on your own, use the recommendations of the car manufacturer.