Ninety-Eight FWD V6-181 3.0L (1985)
tire noise and/or tire roughness.
Small amounts of heel/toe wear on the outer tread is considered normal. This wear is characteristic of new tires at full tread depth on free-rolling axles..
Turning and cornering exaggerates front tire wear. Routine tire rotation at 7,500 miles using the modified "X" method as shown in the Owner's Manual
will minimize the wear. Such tires can be expected to give optimum performance for their full intended life.
If this type of wear becomes excessive and/or results in a customer inquiry, the following procedure should be used:
FIGURE 1
1.
Rotate tires using the modified "X" pattern shown in Figure 1. This allows the front tires to wear in the opposite direction on the rear of the vehicle
which will tend to even out any irregular wear quicker. It also allows all four tires to eventually run on all four positions. Tire noise may continue
after rotation, but should gradually lessen after a few thousand miles.
2.
Measure front wheel alignment. The single most contributing cause of premature tire wear, except for abusive driving, is excessive toe. For best
tire wear, reset toe as close to zero as the specification allows. In most cases, this will be .1~ total toe or less. Camber and caster should also be set
to specification if necessary.
3.
Talk to the customer about their tires. Explain that some amount of shoulder wear on front tires is normal and will even out with regular tire
rotation. Explain that front tire shoulder wear is also exaggerated by hard cornering. Stress the importance of proper inflation pressure and wheel
alignment.
4.
If the wear has advanced far enough, tire replacement may become necessary. When installing new tires, match the tire's high point mark to the
wheel's valve and then balance. Also, wheel alignment must be reset as specified in Step 2 above and the customer instructed to follow the
modified "X" rotation schedule at 7,500 miles.
Irregular Rear Tire Wear - 1984-86 Cutlass Ciera
Some 1984-86 Cutlass Ciera models may develop an irregular wear pattern on the rear tires. This condition may cause tire noise and/or tire roughness
due to the heel and toe (high and low) wear pattern on individual tread blocks. A diagonal wear pattern may also become evident across the face of the
tread.
Excessive toe-in of the rear axle will increase irregular rear tire wear. The rear axle toe-in specification is 0~ +/- 2~. To correct excessive rear axle
toe-in, install shim kit, part number
14094481. Installation of the two shims in the kit, one at each axle end, will reduce toe-in by .4~. Follow instructions included in kit for proper
installation.
CAUTION: Use only GM part number 14094481 shim kit. Use of other parts may cause bolt torque loss which could result in the loss of a wheel and
