eEuroparts.com Car Owners’ Manual – Intro to Wheel Alignment


Wheel alignment is one of those often overlooked parts of car maintenance. This is generally true for most drivers, even some who consider themselves car enthusiasts. As it turns out, wheel alignment plays a major role in how a car behaves, how it tracks, and even how fast it can go through corners. In this installment of the eEuroparts.com Car Owners’ Manual, we’ll go over wheel alignment, why it matters, how it affects performance, and much more! Let’s get started.
wheel alignment 3

What is Wheel Alignment?

Modern cars are a sum of their subsystems, including suspension. One quick glance at your average car’s suspension system reveals a whole array of smaller components working together to make the vehicle controllable and absorb any road imperfections.

Modern suspension systems also dictate how a vehicle tracks. In other words, wheel alignment defines the overall position of the wheels in relation to their X, Y, and Z-axis. Coincidentally, there are three components to wheel alignment — toe, camber, and caster. Each of these can influence how your car handles, both positively and negatively.

Why Is Wheel Alignment Important?

There are two answers to this question. On one hand, wheel alignment can impact your safety in several ways. Have you ever driven behind a car that seemed like it was going kinda sideways on a straight patch of road? Chances are that their alignment was way off, which happens when you completely ignore it.

Since wheel alignment also affects how your tires are contacting the road surface, excessive positive or negative camber, toe or caster can reduce the size of your tires’ contact patch. Needless to say, this can be extremely dangerous.

The other reason why wheel alignment is important is performance. By adjusting the camber, toe, and caster on your car, you can make it more or less compliant to input, but also improve your car’s ability to remain stable through corners. This is especially true for front-wheel-drive cars where you have to individually set up front and rear wheels so that you eliminate as much understeer as possible.

Let’s take a look at each of the three components of wheel alignment and briefly explain their purpose.

Toe-In, Toe Out?

wheel alignment toe
Read the complete guide to toe for more information

Toe represents the angle of a front wheel in relation to a vehicle’s path of travel. In other words, if you imagine that there’s a line running through the middle of your car from the rear fender to the grille, the toe would represent the angle of the wheels in relation to that line. Excessive toe-in alignment means that the wheels are pointed inwards, with their angles intersecting the long axis of the car. Toe-out alignment is the opposite. With toe-out, front wheels are pointing away from each other.

On paper, excessive toe-out alignment makes steering much easier as the wheel closest to the curve is always pointed into the curve. However, toe-out alignment isn’t always the answer. Front-wheel-drive cars usually feature slight toe-out angle to counteract the drive force of the wheels. That being said, rear-wheel-drive cars are the opposite. These are generally shipped with some amount of toe-in angle. The whole toe-in VS. toe-out discussion has more depth to it. Check out our guide for more info.

Camber

wheel alignment camber
Read our complete guide to camber for more information

Camber is by far the most popular part of the alignment, partially due to its impact on performance, but also the aesthetic value it brings to the table. Camber affects the vertical angle of the wheel in relation to the road surface. Positive camber means that the top part of the wheel is pointing out, while negative camber means that it’s pointing inward into the wheel arch.

Negative camber, although aesthetically pleasing, can be a double-edged sword. Adding too much negative camber can reduce the handling capabilities of your car as well as lead to uneven tire wear. That being said, some amount of negative camber is necessary, especially if you’re looking for optimal cornering performance.

Caster

wheel alignment caster
Read our complete guide to the caster for more information

Last but not least, there’s the caster. Caster represents the angle of the upper and lower control arms in relation to the center axis of the wheel. Caster is easy to visualize using upper and lower ball joints. When the two are aligned perfectly, that’s a neutral caster. When the lower ball joint is in front of the upper ball joint, that’s a positive caster. When the upper ball joint is in front of the lower ball joint, that’s negative caster.

Granted, caster isn’t discussed as often as camber or toe, but it still plays a role in wheel alignment, especially when said alignment is done as a part of a suspension setup. A positive caster can improve the handling of the vehicle, as well as make it more stable at higher speeds.

How Often Should You Check Alignment On Your Car?

If we exclude track day cars, racing rigs, and other performance machines, how frequently should you check the alignment on your car? We feel that you should check your alignment at least once a year, especially if you drive your car every day.

Daily driving combined with less-than-perfect road surfaces means that your suspension components could fall out of spec, thus affecting alignment. Is your car going to explode if you skip checking alignment one year? Not really, but you might find that your tires are wearing out unevenly. In more severe cases, you could be dealing with extreme tire deformation that can render brand-new tires useless after a season or so.

How Can You Tell That You Need Wheel Alignment?

Although bad wheel alignment doesn’t often produce dramatic symptoms, there are several surefire ways you can diagnose a bad alignment before it becomes a serious problem. Since bad wheel alignment messes with the orientation of your wheels, your tires are the first thing you should be taking a closer look at.

Tire Wear or Deformation

Look for uneven tire wear on each individual wheel. Sometimes the uneven wear will be obvious, especially if you’re dealing with camber issues. You’ll find that the inside section of the tread is worn out before the middle, the outer section. Or, if you’re dealing with excessive positive camber, the outer section of the tread will show signs of wear.

If a visual inspection reveals nothing obvious, run the palm of your hand along the inner and outer sections of the tread. Bad wheel alignment can typically lead to the formation of ridges along the inside portion of the tread. These ridges or bumps can cause a humming sound that has a frequency to it as well.

Other Symptoms

Another way of telling there’s something off with your alignment would be to take note of how the car tracks. Is it pulling to one side if you let go of the wheel? Remember, good wheel alignment on regular cars means a healthy amount of toe-in, which keeps the car driving straight.

Next, check to see if the steering wheel feels off-center from where you’re sitting. Sometimes if the toe of the front and rear wheels is out of spec, it can cause the vehicle to be pointed slightly to one side or the other.

Lastly, steering wheel vibrations are a common sign that something is up with your alignment, especially if the vibration becomes more apparent when you accelerate.

Stay On Top Of Your Maintenance

The key to long-lasting, healthy wheel alignment is consistent maintenance. Make sure to check everything once a year, and do your best to rotate tires in a timely manner. Doing all these things will help preserve your car’s performance, but also save you a few bucks on tires and suspension parts.

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