Steering and Suspension Systems
Core concepts
Understand steering geometry: camber, caster, toe and thrust angle, and how each affects tyre wear and handling. Know the construction and diagnosis of MacPherson struts, double wishbone and live axle suspension, plus springs, shock absorbers, bushes and ball joints. Cover power steering types, including hydraulic and electric systems, and their fault symptoms. Understand wheel alignment procedures, tyre construction, tread depth and wear patterns. Know how to inspect for play, noise and leakage, and how to test shock absorbers and ball joints safely.
Traps
Questions often test whether camber affects straight-line stability (caster does) and whether incorrect toe causes feathered edge wear. Watch for confusion between a worn shock absorber and a worn spring, and for the assumption that pulling to one side is always an alignment issue when it can be a dragging brake or tyre pressure difference.
Worked example
A vehicle has uneven front tyre wear with feathered edges. Check and correct tyre pressures first, then inspect for play in ball joints and tie rod ends. If components are serviceable, perform a wheel alignment and set toe to specification. Record before and after readings so the customer can see what changed.
Rule of thumb
Check pressures and component condition before adjusting alignment. Alignment cannot fix a worn joint.