Lateral Runout Check

WARNING: This page does not describe the selected car, but rather 30 other vehicles, including the 1998 Pontiac Trans Sport, 1998 Oldsmobile Silhouette, 1998 Oldsmobile Bravada, 1998 GMC Yukon, and 1998 GMC Suburban. However, it is still accessible from the selected car via links, so may be relevant.

The best way to check lateral runout is with the wheels still installed on the vehicle. This gives a much more accurate reading of the total indicated runout under real braking conditions. If equipment is not available to perform the check with the wheels installed, the next best reading can be made with the wheels removed but the caliper still installed.

Clean rotor surface. If the wheel must be removed, reinstall the wheel nuts to retain the rotor. Tighten the wheel nuts to the correct torque specification following the wheel nut tightening sequence.
Fasten a dial indicator to the steering knuckle so the indicator button contacts the rotor surface about .5" (13 mm) from the outer edge.
Set the dial indicator to zero.
Turn the wheel one complete revolution and observe the runout indicated on the dial.
The total indicated runout must not exceed .0003" (.08 mm).
If lateral runout is not within specifications, refinish or replace the rotor as necessary.
In some cases, excessive lateral runout can be improved by indexing the rotor on the hub one or two bolt positions from the original position. If lateral runout cannot be corrected by indexing the rotor, check the hub and bearing assembly for excessive lateral runout or looseness. If the hub and bearing assembly lateral runout exceeds .0015" (.040 mm), repair or replace the hub and bearing assembly.

NOTE: Any time the brake rotor has been separated from the wheel bearing flange, clean any rust or foreign material from the mating surfaces of the wheel bearing flange and rotor. Failure to do so can result in increased lateral runout and brake pulsation.