Along with tire rotation and balancing, Wheel Alignment is an integral part of the regular tire maintenance for your automobile. In addition to providing safe and predictable vehicle control, proper wheel alignment allows for a smooth and comfortable ride for all passengers. Ignoring any performance problems that you may be having, even if they seem relatively minor, could be a costly mistake. If not corrected, you will significantly shorten the life of your tires. Of course, replacing your worn tires is not a complete solution to your problems if you don’t correct the various performance issues you’re having. Said another way, it makes no sense to slap 4 new tires on your car if your vehicle is still out of alignment. And as you may have figured out by now, the first place to look when identifying excessive tread wear is to your vehicle’s alignment.
Once upon a time, all you had to worry about was front wheel alignment for your automobile. Sure enough, the game has changed. Today’s modern suspensions require a precise four-wheel alignment which applies to both front and rear wheel drive vehicles. Optimal alignment can only be achieved through use of a modern alignment system.
The wheel alignment of an automobile (a term we loosely use which includes both cars and trucks) involves adjusting the vehicles suspension as opposed to simply the tire and wheels. Both the direction and the angles that the tires point after the alignment is complete are critically important. In short there are four factors involved in setting an automobile’s alignment to specification: caster, camber, toe and ride height. Let’s dive in a bit deeper:
Casteris the angle of the steering axis. The steering axis is the part of the suspension that supports the wheel and tire assembly. Caster pertains to the feel of the steering as well as high speed stability. If viewed from the side of an automobile, draw an imaginary line drawn between the centers of the upper and lower ball joints and form an angle with true vertical. This is how we define caster. Caster can be positive or negative depending on which side of the centerline you’re dealing with.
When viewed from the front (or rear) of the vehicle, camber describes the inward or outward tilt of your tire. Again, the tilt can be positive or negative depending upon whether it’s tilting outward or inward (this measure specifically refers to the top of the tire in relation to the automobile). Camber is the one adjustment which can be set according to one’s driving habits. In short, the camber adjustment maximizes the tire’s contact with the road while taking into account changes of force which occur while an automobile is turning. If you drive more aggressively when turning (cornering), the negative camber can be increased. Conversely, if your mileage is primarily highway with very little cornering, the positive camber can be increased.
Toe is a term which is used to describe whether the fronts of the tires are pointed inward (toe-in) or outward (toe-out). This is best seen (or envisioned) from above your automobile. During wheel alignment, toe is set with the goal being that the tires roll parallel to each other as the automobile is in motion (this is known as zero toe). Toe settings vary between a front wheel drive vehicle and a rear wheel drive vehicle. With a front wheel drive automobile, the front wheels are often pulling toward each other while the vehicle is in motion. This obviously requires an outward compensating setting (toe-out). Of course the rear wheel drive automobile behaves in exactly the opposite way with the rear wheels pushing away from each other. This requires an inward compensating seeing (toe-in).
Ride height serves as a reference point for all automobile wheel alignments. What is ride height? Quite simply the distance between the frame of your automobile and the road is the ride height. Automobile customization often includes raising or lowering of the vehicle, thus adjusting the ride height. For those that customize their vehicles (and this includes replacing original equipment with a taller or shorter tire), it’s important to remember to have a wheel alignment post-customization.
Tire Wear and Misalignment Troubleshooting Guide
The following troubleshooting guide allows you to see the type of drills your local Tire Dealer or Service Shop employ to solve alignment problems. A competent dealer should be able to quickly identify your issue an offer an appropriate remedy. Of course, by referring to this chart there’s nothing holding you back from doing a self-check on your own tires from time to time. While this is not intended to be a comprehensive list, a periodic self-check could help you spot symptoms earlier than you would have otherwise. Early identification of symptoms leads to early resolution of problems, thus saving you money (and potentially a small fortune).
|Misalignment Condition||Tire Wear Symptom|
|The Camber Setting is Incorrect||Premature smooth wear on either the outside or inside shoulder|
|The Toe Setting is Incorrect||Feathered wear across tread / raised tread block edges|
|The Caster Setting is Incorrect||Excessive shoulder wear, tread blocks showing “heel-toe” wear pattern.|
|Caster setting is Unequal (either the right or left side is out of specification)||Sharp pulling necessitates steering compensation and results in feathered wear.|
|The Toe setting is Unequal (either the right or left side is out of specification)||Sharp pulling necessitates steering compensation and results in feathered wear.|
|A Combination of Two or More Settings are out of Specification.||Irregular tread wear including feathering and various smooth spots|
More often than not, a worn suspension part is truly a symptom of an alignment problem. This has been particularly prevalent on older automobiles. For example, worn springs often lower a vehicle’s ride height and alter its geometry. This creates misalignment as all alignment settings refer to ride height as the primary reference point. Weak springs are also primary contributors to cupped or uneven tire wear.
Ball joints present another issue. The symptoms of worn ball joints include erratic handling, irregular tire wear and slow steering response. Worn tie rods often result in the automobile’s tires literally wandering left to right. As the vehicle is driven, this actually results in a changing toe. If this is an issue in your vehicle, you’ll notice irregular feathering on your tire tread.
In summary, it’s as important to follow your vehicle’s tire maintenance schedule (i.e. alignment, tire balancing, tire rotation) as it is to change the oil in your car. A little bit of attention up front could save you a good chunk of money down the road.