ASE A4 Suspension and SteeringSuspension System Diagnosis and RepairMedium
A customer complains of a vehicle pulling to one side and uneven tire wear on a vehicle with a double wishbone suspension. After performing a visual inspection, the technician notes no bent components or obvious damage. Which of the following alignment angles is MOST likely out of specification and would cause these symptoms?
- AExcessive negative camber
- BIncorrect toe-out on turns
- CExcessive positive caster
- DIncorrect setback
Show answer & explanationAnswer & explanation
Correct answer: A. Excessive negative camber
Excessive negative camber causes the top of the wheel to lean inward, leading to excessive wear on the inner edge of the tire and can contribute to a pull, especially under braking or acceleration, due to the uneven contact patch.
Why the other options are wrong
- B. Incorrect toe-out on turns (Ackermann angle) affects steering response in corners but typically doesn't cause a consistent pull or severe uneven tire wear across the entire tire tread.
- C. Excessive positive caster would cause increased steering effort and potentially a pull, but uneven tire wear due to caster is less direct than camber.
- D. Incorrect setback (one wheel further back than the other) causes the vehicle to 'dog track' and can cause a pull, but the primary tire wear would be scrubbing, not necessarily inner/outer edge wear.
Camber Angle
Camber is the inward or outward tilt of the top of the wheel. Incorrect camber causes uneven tire wear and can affect steering stability and pull.
- Measured in degrees from vertical
- Positive camber: top of wheel leans outward
- Negative camber: top of wheel leans inward
- Affects tire contact patch and wear patterns
Memory trick: Cars Can Take Steering, always check angles.