Wheels and Tires: Testing and Inspection

TIRE AND WHEEL RUNOUT





Radial runout is the difference between the high and low points on the tire or wheel.






Lateral runout is the wobble of the tire or wheel.


Lateral runout of more than 2.0 mm (.080 inch) measured near the shoulder of the tire may cause the vehicle to shake.






Radial runout of more than 1.5 mm (.060 inch) measured at the center line of the tread may cause the vehicle to shake.


Sometimes radial runout can be reduced. Relocate the wheel and tire assembly on the mounting studs (See Method 1). If this does not reduce runout to an acceptable level, the tire can be rotated on the wheel. (See Method 2).


METHOD 1 (RELOCATE WHEEL ON HUB)

1. Drive vehicle 10-15 minutes at highway speed' to adequately warm tire to eliminate tire flat spotting from a parked position.
2. Check wheel bearings and adjust if adjustable or replace if necessary.
3. Check the wheel mounting surface.
4. Rotate wheel on the mounting, two studs over from the original position.
5. Tighten wheel nuts in a crossing pattern until all are properly torqued, to eliminate brake distortion.
6. Check radial runout. If still excessive, mark tire sidewall, wheel, and stud at point of maximum runout and proceed to Method 2.

METHOD 2 (RELOCATE TIRE ON WHEEL)


NOTE: Rotating the tire on wheel is particularly effective when there is runout in both tire and wheel.




1. Remove tire from wheel and mount wheel on service dynamic balance machine.
2. Check the wheel radial runout.




3. Check the wheel lateral runout.
- STEEL WHEELS: Radial runout 0.6096 mm (0.024 in.), Lateral runout 0.762 mm (0.030 in.) (maximum)
- ALUMINUM WHEELS: Radial runout 0.3556 mm (0.14 in.), Lateral runout 0.508 mm (0.020 in). (maximum)

4. If point of greatest wheel lateral runout is near original chalk mark, remount tire 180 degrees. Recheck runout.