Brake Rotor Assembled Lateral Runout (LRO) Measurement
Removal Procedure^ Tools Required
- J 8001 Dial Indicator Set
Notice: Any time the brake rotor is separated from the wheel bearing flange, clean any rust or foreign material from the mating surfaces of the wheel bearing flange and the rotor. Failure to do so can result in increased lateral runout of the rotor and brake pulsation.
1. Clean the rotor surface (1).
Notice: Refer to Fastener Notice in Service Precautions.
2. Reinstall the wheel nuts (2) in order to retain the rotor.
^ Tighten the wheel nuts in a star pattern to 140 Nm (100 ft. lbs.).
3. Fasten the J 8001 to the steering knuckle for front or to the brake mounting flange on the rear axle for rear so that the indicator button contacts the rotor surface about 13 mm (0.5 inch) from the rotor edge.
4. Set the J 8001 to zero.
5. Turn the rotor one complete revolution. Inspect the runout indicated on the dial. If the TIR exceeds 0.15 mm (0.006 inch), refinish or replace the rotor.
In some cases, excessive lateral runout of the rotor may be improved by indexing the rotor on the hub, one or two bolt positions from the original position. Indexing the rotor requires removal and installation of the front brake caliper. For removal of the front brake rotor, refer to Brake Rotor Replacement (Front). For rear brake rotor replacement, refer to Brake Rotor Replacement (Rear).
If the lateral runout cannot be corrected by indexing the front rotor, inspect the hub and the front wheel bearing for excessive lateral runout or looseness. If the hub lateral runout exceeds 0.040 mm (0.015 inch), replace the hub and bearing. If lateral runout of the hub and bearing is within specifications, refinish or replace the rotor as necessary.
If the lateral runout cannot be corrected by indexing the rear rotor, inspect the rear axle shaft flange for excessive lateral runout. If the axle flange lateral runout exceeds 0.040 mm (0.015 inch), replace the axle shaft. If lateral runout of the axle flange hub is within specifications, refinish or replace the rotor as necessary.