Tire Diagnosis - Irregular or Premature Wear

Tire Diagnosis - Irregular or Premature Wear

Tire Diagnosis - Irregular or Premature Wear:

Irregular and premature tire wear has many causes. Some of them are incorrect inflation pressures (1), lack or regular rotation (2), poor driving habits, or improper wheel alignment (3). If the wheel alignment is reset because of tire wear, always reset the toe as close to zero degrees as the specification allows. Refer to Front Toe Adjustment (Service and Repair).

Rotate the tires if:

* The front tire wear is different from the rear.
* The left and right front tire wear is unequal.
* The left and right rear tire wear is unequal.

Check the wheel alignment if:

* The left and right front tire wear is unequal.
* The wear is uneven across the tread of either front tire.
* The front tire treads are scuffed with feather edges on the side of the tread ribs or blocks.


Tread Wear Indicators

Tread Wear Indicators:

The original equipment tires have built-in tread wear indicators to show when the tires need replacement. These indicators appear as bands when the tire tread depth becomes shallow (1, 2). Tire replacement is recommended when the indicators appear in 3 or more grooves at 6 locations.

Wheel Runout

Wheel Runout:

Measure wheel runout with an accurate dial indicator. Measurements may be taken with the wheels either on or off the vehicle, using an accurate mounting surface such as a wheel balancer. Measurements may be taken with or without the tire mounted on the wheel.

Measure radial runout and lateral runout (3) on both the inboard and the outboard rim flanges. With the dial indicator firmly seated next to the wheel and tire assembly, slowly rotate the wheel one revolution and record the indicator reading. If any measurement exceeds the following specifications and there is a vibration that wheel balancing will not correct, replace the wheel. Disregard any indicator readings due to welds, paint runs, or scratches.

Steel Wheels

* Radial runout: 0.8 mm (0.03 in)
* Lateral runout: 1 mm (0.04 in)


Aluminum Wheels

* Radial runout: 0.8 mm (0.03 in)
* Lateral runout: 0.8 mm (0.03 in)

Measure free radial runout (1) on the center of the tire tread. The tread can be taped to present a smooth surface. Measure free lateral runout (2) on the outboard side of the tire nearest to the tread.

Steel and Aluminum Wheels

Free radial runout: 1.5 mm (0.06 in)