Model 4700 Maintenance Manual Drive and Brake
Tire Replacement Any misalignment of the tire and hub while the tire is being pressed onto the hub can damage the hub. For this reason, chamfers are provided on the outside edge of the hub and on the end of the inside diameter of the tire’s metal insert. The chamfers help to center the hub and tire during the pressing operations and reduce the possibility of misalignment. To prevent damage, the hub must be installed on the circular ram with its chamfered side up. 1. Check inside surface of metal insert on new tire. Use sandpaper to remove any scaling or rust. Clean inside of metal insert and lubricate it with a soap solution. 2. Place circular ram on the press table. See Figure 7-39. The length of the ram must be longer than width of the old tire to allow complete removal of old tire. The outside diameter of ram must be small enough to fit loosely in the insert of tire but must be large enough to rest squarely on flat surface on outer edge of hub. Figure 7-39.
Drive Tire Installation
Section 7. Component Procedures Tire Replacement tire. The new tire must be placed in the same position the old tire was installed on hub. You can use a spacer (slightly smaller in diameter than inside diameter of tire insert and same thickness as depth of recess) to obtain correct amount of recession. 4. Position hub assembly with old tire on top of circular ram so outside of wheel is positioned upward. The outside edge of hub has a chamfer to help guide new tire onto wheel. The chamfered edge must always be leading edge when a tire is pressed onto hub. 5. Center hub assembly on top of ram and make sure that they mate squarely. 6. Position new tire with its chamfered insert facing hub. Align new tire and hub so that they are concentric. 7. Begin pressing new tire onto hub and old tire off wheel. Run press slowly for the first few inches of travel, because this is the critical stage of the operation. If tire begins to cock to one side, stop press and realign tire. A sharp jar with soft-headed mallet usually realigns tire on hub. NOTE : If new tire does not press on with a minimum of 5 tons (68,947 kPa) pressure, replace hub. 8. Release press. Remove wheel, tire assembly, and old tire from press table. Inspect wheel and tire assembly.
3. If outside edge of hub is not flush with edge of metal insert in the old tire, measure how far hub is recessed inside
Publication 1160093, Issued: 20 May 2013
7-35
