Wheel alignment refers to the angles at which your wheels contact the road. When these angles are within the manufacturer’s specification, the vehicle tracks straight, tyres wear evenly, and handling is predictable. When they are out, the vehicle pulls to one side, tyres wear prematurely on one edge, and the steering wheel may not sit straight. This guide explains what the alignment angles mean and when you need an alignment.
The Three Alignment Angles
Toe is the most commonly adjusted angle and has the biggest impact on tyre wear. It describes whether the fronts of the tyres point inward (toe-in) or outward (toe-out) when viewed from above. Incorrect toe causes feathered or scrubbed wear across the tread surface. Toe is adjusted by lengthening or shortening the tie rods.
Camber is the inward or outward tilt of the wheel when viewed from the front. Negative camber means the top of the wheel tilts inward, while positive camber means it tilts outward. Incorrect camber causes wear on one edge of the tyre. Camber is adjustable on some vehicles via eccentric bolts, shims, or adjustable control arms, but on many vehicles with MacPherson struts it is not easily adjustable without aftermarket components.
Caster is the angle of the steering axis when viewed from the side. It affects steering feel and straight-line stability but does not directly cause tyre wear. Caster is rarely adjusted on standard vehicles unless there has been collision damage.
When You Need an Alignment
Get an alignment check after fitting new tyres (to protect your investment), after any suspension work (replacing tie rods, ball joints, control arms, struts, or springs), after hitting a large pothole or kerb, if the steering wheel is off-centre, if the vehicle pulls to one side, or if you notice uneven tyre wear. Most alignment shops recommend a check every 12 months or 20,000 km as preventative maintenance.
What Happens During an Alignment
A wheel alignment is performed on a dedicated alignment rack with sensors attached to each wheel. The machine measures the current angles and compares them to the manufacturer’s specifications. The technician then adjusts the toe (and camber if adjustable) to bring the readings within specification. A printout showing the before and after readings is standard practice and worth keeping for your records.
Alignment Specifications
— /wp:heading –>Every vehicle has specific alignment specifications set by the manufacturer. These are listed in the suspension chapter of your workshop manual and include the target angle and the allowable tolerance range for toe, camber, and caster on both front and rear axles. Having these specifications when you visit the alignment shop ensures the technician sets the angles to the correct values for your specific model, not a generic approximation.
Your workshop manual also identifies which angles are adjustable on your vehicle and how to adjust them, which is useful if you are doing suspension work yourself and need to set a rough alignment before driving to the alignment shop. MechanicMate offers PDF workshop manuals for over 960 models at mechanicmate.net/shop.
