ASE A4 Suspension and SteeringWheel Alignment Diagnosis, Adjustment, and RepairMedium
A technician is performing a four-wheel alignment and notes that the front total toe is 0.10 degrees IN. The manufacturer's specification is 0.05 degrees ±0.05 degrees total toe. The vehicle exhibits excessive tire wear on the outer edges of the front tires. Which of the following adjustments should the technician make?
- ADecrease total toe-out.
- BIncrease total toe-in.
- CIncrease total toe-out.
- DDecrease total toe-in.
Show answer & explanationAnswer & explanation
Correct answer: D. Decrease total toe-in.
Excessive toe-in causes the front tires to scrub inward, leading to wear on the outer edges of the tires. The current measurement of 0.10 degrees IN is at the upper limit of the specification, suggesting that reducing the toe-in, or moving it towards toe-out, would be beneficial.
Why the other options are wrong
- A. Decreasing toe-out is the same as increasing toe-in, which would worsen the problem.
- B. Increasing toe-in would worsen the outer edge tire wear.
- C. Increasing toe-out would cause inner edge tire wear.
Toe and Tire Wear
Toe is the inward or outward pointing of the wheels when viewed from above. Incorrect toe settings are a primary cause of rapid and uneven tire wear.
- Toe-in: front of wheels closer together than rear.
- Toe-out: front of wheels farther apart than rear.
- Excessive toe-in causes outer edge wear.
- Excessive toe-out causes inner edge wear.
Memory trick: Toe-in pinches the outside, toe-out stretches the inside.