Steering and Suspension Systems
Steering and suspension fundamentals
Alignment angles are camber (inward or outward tilt at the top), caster (steering-axis tilt fore or aft), toe (front-to-back difference across the tire), and steering axis inclination. Thrust angle compares the rear axle centerline to the vehicle centerline. Worn tie rods, ball joints, control-arm bushings, struts, wheel bearings, and steering gears cause play, noise, or poor returnability. Power steering may be hydraulic or electric.
Traps: caster does not usually cause tire wear but affects straight-line stability and returnability. Camber wear shows as a one-edge wear pattern; toe wear shows as feathered tread. A crooked steering wheel after an alignment may mean the toe was set without centering the wheel. Torque suspension fasteners at curb height when the OEM procedure requires it, or bushings may tear. Check tire pressures and ride height before aligning.
Rule of thumb: toe is the largest single cause of rapid tire wear; a small toe error scrubs the tread continuously. Camber causes edge wear, and caster causes a pull or poor steering return.
Worked example: The vehicle pulls right and the right front tire shows excessive outer-edge wear. Alignment readings show right front camber +0.75 degree and left front -0.25 degree. The more positive camber side tilts outward and can cause a pull toward that side. Adjust camber to specification, then reset toe and center the steering wheel.