Tires are expensive, but a regular alignment check will help them last longer. Not every auto repair shop can perform this task, so you’ll want to find an alignment specialist. Use DexKnows auto repair shops to locate one nearby.
A specialist shop uses sophisticated equipment to ensure that the wheels point in the right direction. And strangely enough, this isn’t straight ahead! Wheels are aligned when the car is stationary, but once it’s moving, acceleration, braking and cornering push and pull the tires into slightly different positions. So to get correct alignment on the highway, the wheels are positioned a little out of true balance.
Now, this may get a little technical, but it will help you understand what the tire store employee is talking about and may help you figure out why your car is vibrating sometimes. Wheels are aligned in three directions: toe, camber, and castor. Toe corresponds to the direction the wheels point; camber is the amount the tops lean in or out; caster is the angle at which the front wheels pivot. If you really want more detail, take a look at specialist websites such as Tirerack or Discount Tire for diagrams.
Toe is the angle between straight ahead and the direction the wheels are pointing. If the fronts of the wheels are pointing inward, that’s termed “toe-in,” and if they are pointing outward, it’s “toe-out.”
In a rear-wheel drive car, the front wheels are set to have some toe-in, while a front-wheel drive car will usually have some toe-out. If the toe is set wrongly on one or more of the wheels, perhaps from hitting a pothole, the wheels will want to move in slightly different directions. The result is that the rubber scrubs across the road surface and the tires wear out quickly. Fortunately, this is easy to see: the tread blocks will look as though they’ve been lifted and the edges of the tires will have a feathered appearance.
Camber is the vertical tilt of the wheels. It’s important because it influences how well the tires grip when cornering. If it’s set wrong, the car may pull to one side.
If the tops of the wheels lean inward, that’s called negative camber. Racing drivers and those who enjoy “enthusiastic” cornering, prefer negative camber because it improves the grip of the road. The downside is that a lot of negative camber can make a car feel “nervous” or twitchy.
Incorrect camber shows up as uneven tire wear. If the top of the wheel leans out too far (excess positive camber), the outside of the tire will wear faster than the inside. If there’s too much negative camber, the inside will wear faster.
Caster describes the line the wheel pivots about when you turn the steering. It’s not too different from how the casters on a shopping cart pivot on the ends of the legs. When you push the cart, the caster naturally follows behind this pivot, so the position of the pivot influences the willingness of the wheels to turn.
On a car, the caster angle affects how the steering feels. It’s not adjustable but might be out of tolerance if the suspension components are very worn or have been damaged. If this is the case, you’ll need to have some parts replaced.
Wheel alignment affects the way your car handles and how long the tires last. Regular wear and tear, especially if you drive on potholed roads, will gradually put these settings outside the manufacturer’s specifications. That’s why it’s wise to schedule an annual visit to a vehicle repair shop where a specialist can carry out tire balancing and an alignment check. SearchDexKnows auto repair shops for one near you.