Steering and wheel alignment
Steering and wheel alignment
This domain tests steering geometry and tire wear diagnosis. The main angles are camber, caster, toe, and thrust angle; also included are steering linkage and power steering checks.
Core rules and concepts
- Camber is vertical tire tilt. Too much negative camber wears the inside edge; too much positive wears the outside edge.
- Caster is steering-axis tilt. It affects straight-line stability and steering return but usually does not cause tire wear.
- Toe is the front-of-wheel difference. Incorrect toe feathers tires. Set toe last, after camber and caster, and center the steering wheel.
- Thrust angle is the rear axle direction. Misalignment causes dog-tracking and an off-center steering wheel.
- Before alignment, check tire pressures, ride height, ball joints, tie rods, and wheel bearings.
- Power steering: check fluid, belt, and leaks; do not hold the wheel at full lock.
Worked example
A vehicle pulls right and the right front tire wears on the inner edge. Pressures are equal. Camber measures −1.5° against a −0.3° specification. Correct camber, then set toe and center the wheel. If camber is not adjustable, inspect for a bent strut or control arm.
Traps that cost marks
Adjusting toe to hide a camber fault; not centering the steering wheel; performing alignment with worn parts; and confusing radial tire pull with an alignment fault.