What is an alignment?
A vehicle is properly aligned when all suspension and steering components are sound and the tyre and wheel assemblies are running straight and true. Proper alignment is necessary for even tread wear and precise steering. Uneven front- or rear-tyre wear, or changes in your vehicle's handling or steering response (i.e., pulling to one side) can indicate misalignment.
Many vehicles today are equipped with rear suspensions that can be adjusted for alignment. Depending on your vehicle's year, make and model you may need a "front-end" alignment or a "four-wheel" alignment. The moderate cost of having your vehicle aligned can more than pay for itself in tyre mileage, performance and comfort.
Wheel alignment terms
Wheel alignment refers to how flat your tyres sit on the ground, and how straight they are pointed down the road. In technical terms, your vehicle's wheel alignment can be measured in terms of (1) camber, (2) toe, and (3) caster.
Camber refers to how flat your tyres sit on the ground. Over time your vehicle's suspension gets weaker and your vehicle actually begins to slowly sag. As this happens your tyres can start to ride on the inside or outside edge. This is referred to as positive and negative camber. The result of positive and negative camber is usually very fast tyre wear.
Toe refers to how straight your wheels are pointed down the road. Wheels that point slightly in towards each other have "toe in." Wheels that point slightly out away from each other have "toe out." When your wheels have significant positive or negative toe, your tyres are literally dragged down the road. The result is often fast tyre wear, or uneven tyre wear which results in tyre noise.
Caster is the orientation of the wheel on the axle. Imagine standing to the side of your vehicle and looking at the wheel and its position within the fender or wheel-well. If your wheel was pushed towards the front of the wheel-well it would have negative caster. If your wheel was pushed towards the back of the wheel-well it would have positive caster. Your vehicle was designed with a specific caster. As the caster changes your vehicle's steering and handling can be effected.
When should you check your alignment?
Most tyre manufacturers recommend you check your alignment every time you purchase new tyres. This protects your tyre investment and increases your satisfaction with the tyre's performance.
Many vehicle manufacturers recommend you check your alignment at the major service intervals such as 30,000 – 60,000 – 90,000 miles. Check your vehicle's owner's manual for your vehicle manufacturer's recommendations.
You should also check your alignment if you have any of the following conditions:
1. Your steering wheel is off center
2. Your vehicle is pulling to one side
3. Your car tends to wander on the highway
4. Your steering is not responsive
5. You have a vibration in the steering wheel
6. Your tyres are wearing faster on the inside or outside edge
7. Your tyres are noisy