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Here’s some food for thought for your next mechanic shop visit. What are the common angles that are adjusted when doing a wheel alignment and why should you care? Correct wheel alignment settings are vital to tire longevity and smooth road operation. Nothing is more fatiguing to a driver than being on an extended drive and having to be constantly fight the steering wheel to keep your vehicle centred on the road. I’ll take a moment to explain the three primary angles that are relative to you and your car:
Toe Angle: Looking from an overhead vantage point, this is the angle of the wheels on the same axle, pointing to the left or the right. When all wheels are exactly straight ahead, this is referred to as neutral toe. Toe-in represents tires that are pointing inwards, or the front of the tires are closer together than the rear. Toe-out is the inverse, where the rear of the tires are closer together. Most contemporary vehicles are factory set with a minimal amount of toe-in, measured in degrees.
Camber Angle: Viewed from the front of the vehicle. This is the leaning in or out of the tire. When they are perfectly vertical, this once again is referred to as neutral, or zero camber. Negative camber represents tires that are leaning inwards, and outwards is positive. All contemporary vehicles employ a slight amount of negative camber, while sports cars use a generous amount more to aid in aggressive cornering.
Caster Angle: This one is the most difficult to explain. Viewed from the side of the vehicle and only applicable to the front, steering wheels. Technically caster is the relationship between the upper and lower ball joints, but I feel explaining it in this manner is hard to visualize.
Instead, I ask you to think of a bicycle and its front forks. All bicycle forks have a forward leaning offset to keep the bicycle stabilized when riding. When you hit a bump in the road, the energy is forced into the bicycle through the front forks. Alternatively, if the forks and steering tube were leaning rearwards, that same bump would wreak havoc and the bicycle would be completely unstable. The front steering wheels on all vehicles have the same orientation as the bicycle and motorcycle. Positive caster in a vehicle stabilizes the vehicle over bumps and improves stability at highway speeds. It also returns your steering wheel to centre after exiting a corner.
As manufactures implement cost cutting measures, the only angle that is guaranteed to be adjustable is the front toe angle. When any of the three angles have been altered by a large pothole or curb hit, odd driving characteristics and increased tire wear will be noticed.
When you send your vehicle in for a wheel alignment, be sure to ask for a colour printout from their wheel alignment machine. Have the service adviser show you where the pre-alignment numbers are displayed, and also where the post alignment results are located on the printout. Pay attention to the post alignment results and look for any results that are still displayed in red. This indicates that a problem is still present. Because of the manufacturer cost cutting measures listed above, not all of these three angles are adjustable any longer. However, even though the angle in question may not be adjustable, you should still be informed that a problem exists and what parts are needed in order to bring the vehicle into an acceptable green range.
Your automotive questions, answered
Hello Lou,
I drive a 2008 Prius with 190,000 km on it. I run on 3-season tires most of the year and switch out to winter tires before the snow flies in Calgary. My winter tires are 2019 Michelin X-Ice XI3s.
Last winter I seemed to have terrible cornering control issues with the Prius. As I drove around long sweeping curves (mainly to the left) at highway speed, it felt like the front end wanted to “dig in” and the back end wanted to swing out. Slowing down to 60 kph and straightening the wheels to less than the curve helped. I don’t get this reaction with my 3-season tires and I am used to the feeling of the Prius being buffeted by wind and uneven roads. Any thoughts on what may be causing this erratic behaviour?
Thanks!
Brian B
Now, I could make some fuel consuming, gearhead oriented Prius jokes about the dangers of going 60 km/h in a Prius, but that would be too easy. Despite my poor attempt at humour, I’m actually impressed by the Prius. They have been around for a while now and are robust, economical, long-lasting vehicles that for the most part, do exactly what Toyota intended.
I assume that since you winter tires were purchased only a couple of years ago that they are still in good shape. Your description of the vehicle’s front end digging in and the back end swinging out describes a situation that is referred to as oversteer.
The easiest, most obvious cause is incorrect tire inflation. The second and more likely answer is the vehicle needs a wheel alignment. Despite the fact that everything feels normal with your three-season tires, the different rubber compounds of the winter tires can sometimes accentuate and amplify the odd driving dynamics caused by an incorrect alignment wheel angle. Further to that, if it is happening when you are mainly turning to the left further supports that an alignment angle referred to as toe is out of spec on the left front. I’m confident that a simple wheel alignment will correct this situation.
Hi Lou,
We have a 2016 Honda CRV and I am very surprised with the frequency with which they recommend services not specifically mentioned in their national service recommendation pamphlet. Specifically, they are recommending alignment at 24,000 km! This is a point when the vehicle is virtually new. In my experience, alignment is not done until 50,000 miles (80,000 km). Of course you could do it sooner if you see signs of uneven tire wear, feel vibration or have pulling to one side or the other. Also, they are promoting a “fuel induction service” to clean injectors, valves, ports and fuel lines at 40,000 km. My feeling has been that this type of service is not required until about 100,000 km given the ultraclean fuels that we put in our vehicles nowadays. Am I wrong?
Regards,
Ralph R
Wheel aligners are expensive pieces of equipment, but produce a large ROI when they are being employed all day long. Wheel alignments are not required every 24,000 km. I would say the ideal interval is every two to three years, when tires have odd wear, at a new tire purchase interval or after a teeth-rattling pothole or curb impact. Forty-thousand kilometres for a fuel induction service is also early in my opinion.
So yes, the two services you have mentioned are readily sold to customers because they are at the very top of the easy money list. Your vehicle has a built-in maintenance minder system dictating what service is required and when. Use that as your guide for future servicing requirements.
Lou Trottier is owner-operator of All About Imports in Mississauga. Have a question about maintenance and repair? E-mail globedrive@globeandmail.com, placing “Lou’s Garage” in the subject line.
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The Link LonkJune 26, 2021 at 04:00PM
https://www.theglobeandmail.com/drive/mobility/article-the-three-methods-of-wheel-alignment-you-need-to-understand-for-a/
The three methods of wheel alignment you need to understand for a better drive - The Globe and Mail
https://news.google.com/search?q=Wheel&hl=en-US&gl=US&ceid=US:en
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