Tire and Wheel Match Mounting

STANDARD PROCEDURE
Tires and wheels are currently match mounted at the factory. Match mounting is a technique used to reduce runout in the wheel/tire assembly. This means that the high spot of the tire is aligned with the low spot on the wheel rim. The high spot on the tire is marked with a paint mark or a bright colored adhesive label on the outboard sidewall. The low spot on the rim is identified with a label on the outside of the rim and a dot on the inside of the rim. If the outside label has been removed the tire will have to be removed to locate the dot on the inside of the rim.

Before dismounting a tire from its wheel, a reference mark should be placed on the tire at the valve stem location. This reference will ensure that it is remounted in the original position on the wheel.

Fig. 3:

Fig. 8:

1. Use a dial indicator to locate the high spot of the tire on the center tread rib. Record the indicator reading and mark the high spot on the tire. Place a mark on the tire at the valve stem location.

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2. Break down the tire and remount it 180 degrees on the rim.
3. Measure the total runout again and mark the tire to indicate the high spot.
4. If runout is still excessive use the following procedures.
a. If the high spot is within 101.6 mm (4.0 in.) of the first spot and is still excessive, replace the tire.
b. If the high spot is within 101.6 mm (4.0 in.) of the first spot on the wheel, the wheel may be out of specifications.

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c. If the high spot is NOT within 101.6 mm (4.0 in.) of either high spot, draw an arrow on the tread from second high spot to first. Break down the tire and remount it 90 degrees on rim in that direction. This procedure will normally reduce the runout to an acceptable amount.