Wheel alignment basics: what it is and when you need one

Alignment sounds technical, but the idea is simple. It means setting the angles of your wheels so they point the way the car's maker intended and meet the road flat. Nothing is added to the car and no tire is replaced. The suspension is adjusted so that all four wheels work together.

What gets adjusted

Three angles matter most, and a technician measures each one on an alignment rack.

• Toe is how far the fronts of the tires point in or out, as if you were looking down at your own feet. Even a small toe error drags the tire sideways as it rolls.
• Camber is the inward or outward lean of the wheel when viewed from the front. Too much lean loads one edge of the tread.
• Caster is the forward or backward tilt of the steering axis. It helps the wheel straighten itself after a turn and keeps the car steady on the highway.

Signs your alignment is off

Alignment rarely fails all at once. It drifts, and you tend to adapt without noticing. Watch for these clues:

• The car pulls to one side on a flat, straight road when you loosen your grip slightly.
• The steering wheel sits off-center while the car is going straight.
• The tread on the inside or outside edge of a tire is wearing faster than the rest.
• The tires squeal on ordinary turns, or the car feels loose and wandering at highway speed.
• Steering feels less eager to return to center after a corner.

Some of these symptoms can also come from an out-of-balance wheel, low tire pressure or a worn suspension part. That is why a good alignment visit starts with an inspection rather than a quick adjustment.

Tip: Run your hand across the tread of each front tire. If it feels smooth in one direction and sharp or feathered in the other, the tire is being dragged sideways and the alignment deserves a look.

What knocks alignment out of spec

Potholes, curbs and railroad crossings take a toll over time, and so does a minor fender-bender you barely noticed. Worn ball joints, tie rod ends and control arm bushings let angles wander even if you never hit anything. Changing the ride height with lowering or lift kits also changes the angles, so it should always be followed by an alignment.

When to get it checked

There is no single mileage that suits every car, but these moments are sensible checkpoints:

1. When you install a new set of tires, so the fresh tread starts out wearing evenly.
2. After replacing steering or suspension parts such as tie rods, struts or control arms.
3. After a hard impact with a curb or a deep pothole.
4. Once a year if you drive on rough roads, or whenever you notice pulling or uneven wear.

Why it pays off

A properly aligned car tracks straight, needs fewer steering corrections, and puts less strain on suspension parts. The biggest savings show up in your tires. A set that should last years can lose a large share of its life when the angles are wrong, and tires are one of the larger routine costs of owning a car. Better rolling resistance can also help fuel economy slightly.

Alignment and tire rotation work together

Rotating your tires on schedule spreads wear across all four positions, but it cannot fix a bad angle. If an alignment problem is present, rotation only delays the damage a little. Keep up with both, and check tire pressure monthly, since a tire that is low on air can wear unevenly and make the car feel off even when the angles are perfect.

What to expect at the shop

An alignment visit usually takes about an hour. The technician inspects the tires and suspension, mounts sensors on each wheel, reads the current angles and adjusts what can be adjusted. You should receive a printout or a plain explanation of the before and after readings. If a worn part prevents a correct setting, it should be explained to you before anything else is done, with the price approved by you first.

At Northline we do this as part of our brakes, steering and alignment work, but the advice above applies wherever you take your car.