Lateral Runout Check

Fig. 1 Checking Rotor For Lateral Runout:

1. If applicable, ensure wheel bearings are properly adjusted.
2. Mount a dial indicator to a convenient part of the vehicle (steering knuckle, tie rod, disc brake caliper housing).
3. Position dial indicator plunger so it contacts the disc at a point one inch from the outer edge.
4. Rotate the rotor and note the dial indicator readings. Perform this check on both inboard and outboard rotor faces.
5. On hub type rotors, if runout exceeds specifications proceed as follows:
a. If the rotor cannot be machined, replace it.
b. If the rotor can be machined, resurface it, then proceed to step c.
c. If runout still exceeds specifications, replace the rotor.
6. On hubless type rotors, if runout exceeds specifications proceed as follows:
a. Reposition rotor on the hub, then recheck runout.
b. If runout still exceeds specifications, replace the rotor.