TIRE /WHEEL VIBRATION EXISTS SPECIAL HANDLING TIRES. Pontiac Grand Prix 1985

ALL MODELS EQUIPPED WITH HIGH PERFORMANCE TIRES

If a tire/wheel vibration exists on vehicles equipped with high performance tires, such as Goodyear Eagles, improvement can often be obtained by simply unseating and re-seating the tire on the rim. The following procedures should be followed:

1. Normal vibration diagnosis procedures should first be performed. This should include road test, visual inspection, wheel balance check, runout measurements, etc.

2. If a tire/wheel induced vibration still exists, unseat both tire beads from the rim using a tire changing machine. Do not remove the tire from the wheel; do not rotate the tire on the wheel.

3. Lube both tire beads and the rim's bead seat areas liberally with an approved tire lubricant. Make sure there is no accumulation in the tire.

4. Re-seat both beads on the rim by inflating the tire to 40 PSI (275 KPA). Adjust the inflation downward to the recommended placard pressure.

CAUTION:

Do not stand over tire when inflating. Do not exceed 40 PSI (275 KPA) pressure when inflating. If 40 PSI (275 KPA) pressure will not seat beads, deflate, relubricate, and re-inflate. Overinflation may cause the bead to break and result in personal injury.

5. Re-balance the tire/wheel assembly if necessary. (Wheel balancing machines should be calibrated on a regular basis to ensure their accuracy.)

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.