Wheel Alignment

Wheel alignment is not a single part but a set of geometric angles that define how each wheel is oriented relative to the vehicle and to the road surface. These angles — camber, caster, toe, and thrust angle — are engineered into the suspension design for specific handling, ride, and tyre wear characteristics. They require periodic measurement and adjustment because road impacts, worn suspension components, and the gradual settling of rubber bushings all cause the angles to drift from their original specification. Correct alignment ensures the tyres roll in their intended direction, maximising the contact patch, minimising rolling resistance, and providing the designed steering response. The front axle is always adjustable for toe on all vehicles; camber and caster may also be adjustable depending on the design. Rear axle alignment is adjustable on most modern passenger cars with independent rear suspension. Alignment is checked using a four-wheel alignment machine that measures all angles simultaneously via sensors mounted on each wheel and compares them against manufacturer specifications stored in the machine’s database. The correct alignment settings are specific to the vehicle make, model, trim level, and sometimes option packages.

The four primary alignment angles each affect a specific aspect of vehicle behaviour. Camber is the inward or outward tilt of the wheel when viewed from the front — negative camber (top of wheel tilted inward) increases cornering grip but accelerates inner tyre edge wear; excessive positive camber wears the outer edge. Caster is the forward or backward tilt of the steering axis when viewed from the side — positive caster provides self-centring tendency and directional stability at speed, but increases steering effort; insufficient caster causes steering that wanders and fails to return to centre. Toe is the inward (toe-in) or outward (toe-out) angle of the wheel when viewed from above — slight toe-in on the front axle improves straight-line stability; incorrect toe is the fastest way to destroy tyres, scrubbing them sideways with every metre of travel. Thrust angle is the direction the rear axle points relative to the vehicle centreline — a rear axle that thrusts to one side causes the vehicle to dog-track (drive at a slight diagonal) and requires the driver to hold constant steering correction to maintain a straight line.

Vehicle pulling to one side: The most common symptom of misalignment. Caused by unequal camber or toe between left and right wheels, or by a thrust angle problem at the rear. Distinguished from pull caused by a flat tyre by the consistency of the pull — alignment pull is constant; tyre-related pull varies with speed. Confirm by swapping front tyres side to side — if the pull reverses direction, the tyre is responsible; if it stays the same, alignment is the cause.

Rapid or uneven tyre wear: The most expensive consequence of misalignment. Toe errors cause feathering (diagonal sawtooth pattern across tread blocks). Excessive camber causes one-sided shoulder wear. Persistent misalignment can consume 10,000–20,000 km of tread life in just a few thousand kilometres of driving.

Steering wheel off-centre when driving straight: Indicates that front toe settings are unequal between left and right sides, or that the rear thrust angle is offset. Corrected by resetting front toe to equal values while centring the steering wheel.

Level 1 — Regular Monitoring: Check tyre wear patterns at every tyre rotation — feathering across the tread or accelerated single-shoulder wear is the earliest measurable sign of misalignment. Note whether the vehicle requires steering correction to maintain a straight line on a flat, crowned road. Check whether the steering wheel sits centred when driving straight. Any of these symptoms warrants alignment measurement at the next service.

Level 2 — Alignment Every 20,000–30,000 km: Have four-wheel alignment checked and adjusted every 20,000–30,000 km regardless of whether symptoms are present, after any significant pothole or kerb impact, and after any front or rear suspension component replacement. Inspect all suspension and steering components for wear before accepting an alignment result — aligning over worn bushings or ball joints produces a reading that shifts immediately once the worn components move under load.

Level 3 — Professional Service: Alignment adjustment requires manufacturer-specific specifications — never use generic values. Some adjustments require loosening suspension components under load, which requires a four-post lift and an experienced technician. On vehicles where the factory design does not provide camber adjustment, aftermarket adjustment kits (offset bolts, cam bolts) allow correction within a limited range; these should only be used when factory adjustment is exhausted.