Suspension, Steering, and Wheel Alignment
Suspension, Steering, and Wheel Alignment
This domain tests inspection of tires, springs, dampers, joints, steering linkage, wheel bearings, and alignment angles. The exam expects you to find worn parts before setting alignment.
Core rules
- Check tire pressures, tread depth, and wear pattern first. Uneven inner or outer shoulder wear points to camber or toe; cupping points to dampers or balance; a single spot may be a brake or bearing fault.
- Inspect ball joints, tie-rod ends, strut mounts, and wheel bearings with the vehicle safely supported and the suspension loaded or unloaded as the test requires.
- Camber is vertical tilt, caster is steering-axis tilt, and toe is the difference between front and rear of the tires. Thrust angle compares the rear axle to the vehicle centerline.
- Set alignment with the specified load and tire pressures; reset steering-angle sensors and driver-assist systems after alignment where required.
Worked example
A car pulls right and the front tires show feathered edges. Tire pressures are correct. A front-end inspection finds a worn right tie-rod end. Replacing it and setting toe without checking camber and caster would leave the pull unresolved. After replacement, measure all angles: if camber is out of range, look for a bent strut or knuckle. The pull is diagnosed from the tire wear and angle readings, not from the steering wheel position alone.
Traps
Adjusting toe with worn joints, aligning a vehicle with incorrect tire pressures, forgetting to center the steering wheel, and ignoring rear thrust angle. Also, do not diagnose a pull from a road test alone on a crowned road.