General Information

4700 mm 33.07.001

The axles and wheels are aligned at Western Star using Hunter laser alignment equipment. Correct front axle alignment is needed to ensure long tire life, ease of handling, and steering stability.

  1. Camber is the vertical tilt of the wheel as viewed from the front of the vehicle. Camber angle is measured in degrees, and is not adjustable. Negative camber is the top of the wheels tilted inwards. Front tires wearing on the inboard side may be due to excessive negative camber. See Fig..

    • One side of tread is worn excessively.

    Fig. 1, Tire Wear Due to Excessive Camber

  2. Caster is the tilt of the knuckle pin (or king-pin), as viewed from the side. Caster angle is measured in degrees and is adjustable. An incorrect caster angle does not cause tire wear. However, a positive caster angle that exceeds specifications could cause vehicle shimmy and an increased steering effort. Excessive negative caster angle could cause unstable steering, and the vehicle may wander and weave.
  3. Wheel toe-in is the distance that the front of the wheels are closer together than the rear of the wheels. Wheel toe-in is adjustable. If toe-in is not correct, the vehicle could pull to one side while driving. Wheel shimmy and excessive tire wear could occur. The tires would display indentations on the road contact surfaces of the tread. Also, a rapid wear on the steering axle could occur usually in a feathered-edge pattern. See Fig.. Feathered-edging more often affects the front tire on the passenger's side of the vehicle, and is usually more apparent on the outside groves of the tire. If any of these listed conditions occur, the vehicle could need a front end alignment.

    • Feathered-Edges.

    Fig. 2, Tire Wear Due to Excessive Toe-In

Note:
Parent topic: Wheel Alignment Check
Document Number: 0000120950
Manual Publication Date: 2024-05-23
Topic Publication Date: 2024-10-31