Runout

NOTE: Runout should always be measured off the vehicle and on a suitable balance machine.

Radial run out is the difference between the high and low points on the outer edge of the tire or wheel. Lateral run out is the total side-to-side wobble of the tire or wheel. Radial run out of more than 0.762 mm (0.030 inch) measured at the center line of the tread may cause the vehicle to shake. Lateral run out of more than 0.762 mm (0.030 inch) measured at the side of the tire as close to the tread as possible may cause the vehicle to shake. Sometimes radial run out can be reduced by relocating the wheel and tire on the wheel studs (See Method 1). If this does not reduce run out to an acceptable level, the tire can be rotated on the wheel. (See Method 2).

METHOD 1 (RELOCATE WHEEL ON HUB)
Check accuracy of the wheel mounting surface; adjust wheel bearings.

Fig. 2:

Drive vehicle a short distance to eliminate tire flat spotting from a parked position.
Verify all wheel nuts are properly torqued.

Fig. 3:

Use run out gauge D-128-TR to determine run out.
Relocate the wheel on the mounting studs, two studs over from the original position. Retighten wheel nuts until all are properly torqued. This will prevent brake distortion.





Check radial run out. If still excessive, mark tire sidewall, wheel, and stud at point of maximum run out and proceed to Method 2.

METHOD 2 (RELOCATE TIRE ON WHEEL)
Rotating tire on wheel is particularly effective when there is run out in both tire and wheel.
Remove tire from wheel and remount wheel on hub in former position.

Fig. 5:

Check the radial run out of the wheel. The radial run out should be no more than 0.5 mm (0.020 inch) for steel wheels and 0.38 mm (0.015 inch) for cast aluminum wheels.

Fig. 6:

Check the lateral run out of the wheel. The lateral runout should be no more than 0.8 mm (0.032 inch). If the point of greatest wheel radial run out is near the original chalk mark, remount the tire on the rim 180 degrees from its original position. Recheck the run out. If this does not reduce the run out to an acceptable level, replace the wheel and/or the tire.