Car Advice

Wheel alignment is important but so is radial pull…

Everybody wants a car that tracks straight and doesn’t abuse its tyres, and that’s why wheel alignment is so important.

IT MAY SEEM STRANGE, but your car’s wheels don’t exactly line up straight with the direction of the car. They might be splayed out a bit, known as toe-out, or splayed in, known as toe-in.

And they may not be set to exactly vertical either, usually tipped in a little so they’re leaning inwards. This deviation from the vertically-up position is known as camber.

The differences are tiny, just a degree here or there, but they are important for all sorts of reasons. Handling is one, tyre wear is another, and then there’s braking efficiency and fuel efficiency.

Your manufacturer will have settings for the car’s alignment; camber, caster, toe and more. Almost all the time, you want to keep to these settings which your wheel alignment shop can look up for you. However, there are some rare occasions when you may wish to deviate. For example, my Toyota 86 does a lot of track work so I’ve changed the front toe setting to 0-degrees and reduced the rear toe – I am sacrificing straight-line stability for maneuverability. The differences are tiny, but they are there and noticeable on the track.

You should get your wheels aligned whenever you have new tyres, suspension changes or after a major pothole hit. In fact, last week I was driving my 86 along a temporary road which skirted some housing development. It was dark, wet and I thought I knew the road… until I felt that pothole. Yep, that was a wheel alignment right there. Pity I wasn’t in my Ford Ranger as it would have just laughed it off.

And it’s actually the Ranger I want to talk about, though. I recently replaced all five tyres with Goodyear Wrangler MTRs, and of course had the alignment done. Then over the next day or two I noticed there was a slight pull to the left. That shouldn’t have been the case, or if there was an issue that meant it couldn’t be adjusted out then I should have been informed about it. Sometimes suspension components are bent and that means alignment will never be able to come back within limits, but that’s not the case on my cars.

I presumed the alignment was on spec so it had to be something else. The tyre pressures were all within limits, and anyway it needs to be a significant difference between tyres to create a pull – low tyre pressures increase rolling resistance, and cause a lean into the low-pressure tyre which exaggerates the problem. But my pressures were fine.

Now I have a fairly low opinion of chain tyre shops in general, based on my own experience and that of readers. I could list their sins – selling people tyres that are illegal because they’re too low a load rating for the car, attempting to apply the alignment settings of a 2004 solid-axle Discovery 2 to my fully-independent suspension 2008 Discovery 3. But there are good alignment shops and my usual local one diagnosed the problem in short order. It was radial pull.

Despite mass-production techniques every tyre is built slightly differently. There are tiny variations in weight, distribution of weight, where the steel belts are set and so on. This is why all tyres and wheel combinations are balanced, which is adding tiny weights around the wheel to even it out so it rotates smoothly. As the steel belts inside the tyre are a bit offset the tyre doesn’t inflate quite evenly across its tread width, leading to the pull. This is also known as tyre conicity.

The end result is the drag each tyre creates is slightly different, and even though the wheel alignment may be perfect, that uneven drag can result in a pull to the left or the right. There are special tools to measure the drag on a tyre via a jig, which some alignment shops use, or you can just drive the car, test, swap the tyres from left to right, and see if it pulls in the opposite direction.

The fix is quite easy; if the tyres are new and the problem is bad replace the faulty tyre, or swap the tyres left or right so the pull doesn’t happen, use the faulty tyre as a spare, or put it at the back of the car where the problem is less apparent. But to fix the problem you must first diagnose it, and then know how to fix it. Sadly, that’s where many tyre shops are found wanting, but at least now you know something about it should you find an odd pull to either the left or right with your cars.


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Andrew Riles
Andrew Riles
3 years ago

Robert, radial pull is something I’ve never heard of, is it more likely to occur with 4WD and truck tyres because they are generally larger and heavier than passenger tyres??

Robert Pepper
3 years ago
Reply to  Andrew Riles

Yes and because they have more plies and belts. Wider tyres also more prone to it.

Andrew Riles
Andrew Riles
3 years ago
Reply to  Robert Pepper

Ok thanks….

Paul Gillies
Paul Gillies
3 years ago
Reply to  Robert Pepper

And we see more of this at our Indy shop with customers bringing in cheap low-profile tyre purchased from those franchise shops (BJ etc)

Robert Pepper
3 years ago
Reply to  Paul Gillies

Paul, sounds interesting. Want to expand on this and other problems you see?

trackdaze
trackdaze
3 years ago

This is not the same as an out of round tyre? Which can be fixed with a tyre truer (shave)

Robert Pepper
3 years ago
Reply to  trackdaze

Similar but different. An out of round tyre has more tread where it shouldn’t have tread. A tyre suffering from conicity has a carcass that is out of true.

trackdaze
trackdaze
3 years ago
Reply to  Robert Pepper

Cheers.

Any specific tips for taking a few Rangers through the simpson desert Interested in fuel use.

Alva Ortiz
1 year ago

Wheel alignment is all about adjusting the angle of the tires. The purpose is to make everything compatible with the auto maker’s optimal specification. Toe, camber and caster- are three major adjustment that you have to do for keeping all the wheels of the vehicle aligned. Going through your owner’s manual will help you to identify the right interval in which your vehicle needs wheel alignment. The cost of wheel alignment is much lower than the cost of a tire replacement. So, you should never feel hesitate to do wheel alignment whenever it is needed.

Victoria Addington
4 months ago

I am currently looking for a wheel alignment service for my truck here in Melbourne. I noticed that it’s difficult for me to move to another direction when driving. Perhaps, there must have been a misalignment. However, I’m planning to get new wheels that is perfect for all season to avoid sliding. With that, I shall then follow your tip on getting my wheels aligned when I have new tyres.

Robert Pepper

Robert Pepper