Brake Rotor Assembled Lateral Runout (LRO) Measurement

A vehicle that has rotors with excessive lateral runout can exhibit brake pulsation or a shudder condition during braking.

^ Tools Required
- J8001 Dial Indicator Set

1. Raise and support the vehicle. Refer to Vehicle Lifting.
2. Before performing the brake rotor lateral runout check, inspect the wheel bearing/hub for excessive looseness and excessive lateral runout. Refer to Wheel Bearings Diagnosis - Sealed.
3. Remove the tire and wheel. Refer to Tire and Wheel Removal and Installation.
4. Install and tighten the wheel nuts in order to retain the rotor.





5. Fasten the J 8001 to the knuckle. Ensure that the J 8001 button contacts the rotor surface about 13 mm (0.500 inch) from the rotor outer edge.
6. Set the J 8001 to zero.
7. Rotate the rotor one complete revolution. Inspect the J 8001.
^ If the runout exceeds 0.080 mm (0.003 inch), proceed to Step 8.
^ ^ If the runout is less than 0.080 mm (0.003 inch), proceed to Step 13.
8. Mark the relationship of the rotor to the hub.

Notice: Whenever the brake rotor has been separated from the wheel bearing flange, clean any rust or foreign material from the mating surface of the rotor and flange with the J 42450 hub cleaning kit. Failure to do this may result in increased lateral runout of the rotor and brake pulsation.

9. Remove the brake rotor. Refer to Brake Rotor Replacement - Front or Brake Rotor Replacement - Rear (Export).
10. Clean any rust or foreign material from the mating surface of the rotor and the hub.
11. Install the brake rotor on the hub, one or two bolt positions from the rotor's original position. Repeat Steps 5 through 8.
12. If the runout still exceeds 0.080 mm (0.003 inch), refinish or replace the rotor as necessary.
For the front rotor refinishing procedure, refer to Refinishing Brake Rotors.
13. Remove the wheel nuts securing the rotor to the hub.
14. Install the tire and wheel. Refer to Tire and Wheel Removal and Installation.
15. Lower the vehicle.