Tire Dismounting and Mounting Procedure

Use a tire changing machine in order to mount or dismount tires. Follow the equipment manufacturer's instructions. Do no use hand tools or tire irons in order to change tires as these tools may damage the tire bead or wheel rim.

Clean the rim bead seats with a wire brush or coarse steel wool in order to remove lubricants, old rubber and light rust. Before mounting or dismounting a tire, lubricate the bead area with an approved tire lubricant such as GM P/N 9985555 (50 percent lubricant/50 percent water) or the equivalent.

After mounting, inflate the tire until beads are seated, but never exceed 275 kPa (40 psi) to seat the beads.

Caution: To avoid serious personal injury, do not stand over tire when inflating. The bead may break when bead snaps over safety hump. Do not exceed 275 kPa (40 psi) pressure when inflating any tire if beads are not seated. If 275 kPa (40 psi) pressure will not seat the beads, deflate, lubricate the beads and reinflate. Overinflation may cause the bead to break and cause serious personal injury.

Install the valve core and adjust to the proper pressure. Inspect the locating ring of the tire in order to ensure that the ring shows around the rim flanges on both sides.

Tire Dismounting and Mounting Non-Uniformed Tires

There are two ways to correct tires which cause a vibration even though they are properly balanced. One method uses an automatic machine which loads the tire and buffs small amounts of rubber from the stiff spots on the outer two tread rows. Correction by this method is usually permanent and, if done properly, does not significantly affect the appearance or tread life. Truing a tire for free runout with a blade-type machine is not recommended. Using this method reduces the tread life substantially and often does not permanently correct the problem.

Another method is to dismount the tire and rotate it 180 degrees on the rim. It is important that this be done on tire and wheel assemblies which are known to be causing a vibration as it is just as likely to cause good assemblies to vibrate.

Refer to Vibration Diagnosis in Vibration Diagnosis and Correction for more details.