Ask Jack - How do I know if I need a wheel alignment?

Posted by: Jack on 3/07/2012

Category: Maintenance

We all know that our vehicles need a wheel alignment from time to time. No doubt you have heard that it’s very important and that if you don’t do it often enough you risk wasting precious time and money replacing tyres prematurely. But how do you know when to check the wheel alignment on your vehicle?

Before we go into the detail of how often you should have your wheels aligned, let’s take a quick look at what a wheel alignment is and how it affects your car. In essence, a wheel alignment is a series of measurements and adjustments made to your car to ensure that all the wheels are parallel to each other (to the degree specified by the manufacturer) then a second series of adjustments to ensure the wheels are perpendicular to the ground.

The measurements are as specific as possible, and will vary depending on the year, make and model of your vehicle. The whole point of maintaining a good wheel alignment is to minimise the resistance your tyres create by having them roll smoothly and in line with each other. This helps you save on petrol costs and
helps your tyres last longer.

Take a look at this series of pictures showing three of the main measurements that go into a wheel alignment:

 Camber affects the wear of your tyres on the inside or outside of the tread.

 

Caster measurements relate to the steering inputs on the front tyres

 

Toe measurements show tyre position from a top-down view 

 

As you can see, there are several ways that a wheel can go out of alignment, and any wheel being out of alignment will affect your whole vehicle.

That’s all well and good, but what is ‘out of alignment’?

We’ve already established that a wheel alignment is very precise and the correct alignment settings are sensitive. How sensitive? Well there are 360 degrees in a circle and each of those degrees is made up of 60 minutes. Many vehicles have a tolerance of less than ten minutes before a wheel is considered ‘out of
alignment’. That’s one-sixth of a degree!

So the next thing to consider is what makes a car go out of alignment. Understanding this can help you to avoid the hazards and kinds of driving that cost you money.

Your car can go out of alignment in a variety of ways but the most common is by hitting something with a tyre at force. Often this is running over a pothole, or an obstacle in the road like the gutter. This kind of sudden jolt can put your wheel out of alignment immediately.

If you do have an incident like this, then you should definitely have your vehicle checked as soon as possible. Given how sensitive the tolerances are, and the direct impact it has on your finances, it’s better to check the alignment if you’re uncertain.

The second most common way for a car to gout out of alignment is through normal wear and tear in your front end and the suspension. Worn parts shift over time and this can have an impact on your wheel alignment. Often having a simple alignment check done will alert you to issues before they turn into major
problems.

Remember too, that any time you replace a part of your steering assembly or suspension, it’s wise to have an alignment check as well. Most good mechanics include this in the job.

The final way that you may find your wheels out of alignment is as a result of regular wear and tear in your tyres. After all, an alignment is a series of very precise adjustments that are designed to give your vehicle the best possible performance and safety, and so the diameter of your tyre can have an effect on
your alignment. That means that as your tyres wear through normal use, the measurements change slightly. When they change, so does your alignment.

This is why it’s important to regularly check your alignment. General car maintenance guides would suggest that you check your wheel alignment every 10,000 kilometres you travel or twice a year, whichever is most often. This is to ensure that you never get too far out of alignment before it’s adjusted.