Tire rotation, balance and vibration

Why tires wear unevenly

Each corner of the car does a different job. On a front-wheel drive car, the front tires steer, pull the car and take most of the braking, so they wear faster than the rear. Rear-wheel drive spreads the work differently. All-wheel drive cars can be sensitive to differences in tread depth between tires, so keeping wear even matters more on them.

Moving the tires to new positions at intervals evens out the wear, so the set lasts longer and wears down together instead of two at a time. When the time comes, you replace all four together, and grip stays even from front to back.

Rotation patterns

• Front to rear on the same side: the pattern for directional tires, which only work rolling one way and cannot cross to the other side.
• Crisscross: one axle moves straight, the other crosses sides. Common on non-directional tires; which axle crosses depends on which wheels drive the car.
• Side to side only: for cars with a different size front and rear, where tires cannot move between axles.
• Five-tire rotation: some cars with a full-size matching spare bring it into the pattern.

Your owner's manual shows the pattern the maker wants for your car. We follow it, and we check the markings on the tires before anything moves.

How often to rotate

Tire makers commonly suggest rotating every 5,000 to 8,000 miles. Your owner's manual has the interval for your car, and that is the number to follow.

A rotation is also a good time to check pressure, tread depth and any damage while the wheels are off, and to balance the tires if you have felt a shake. We can rotate the tires at the same visit as an oil change.

Rotation spreads wear around. It does not fix the cause of uneven wear. If one edge of a tire is worn smooth, rotating it just moves the problem to another corner. That calls for an alignment.

Tire rotation

What balancing does

No tire and wheel are perfectly even in weight. A spot as small as a quarter ounce heavier can cause a vibration at 50 mph and above. A balancer spins the wheel and tire together, finds the heavy spot, and shows where to put small weights on the opposite side so the assembly spins evenly.

An imbalance can show two ways. A heavy spot can make the wheel hop up and down as it turns, or wobble side to side. The weights are either clipped onto the rim edge or stuck to the inside of the wheel, depending on the wheel; stick-on weights keep the face of a styled wheel clean.

Balancing is worth doing when tires are mounted, after a flat repair, with a rotation, after a hard pothole or curb hit, and any time a new vibration shows up. Low-profile tires, the ones with short sidewalls, show an imbalance more than tall ones do.

Balance and alignment are different jobs. Balance is about the wheel and tire spinning smoothly. Alignment is about the angles of the suspension, so the wheels point straight and the tires meet the road flat.

Mount and balance, done while you wait

Reading a vibration

Steering wheel or seat

A shake in the steering wheel that starts around 45 to 50 mph and gets worse with speed usually points to a front wheel out of balance. If you feel it more in the seat or the floor, look at the rear wheels first.

Only when you brake

If the vibration shows up only when you press the brake, often with a pulsing pedal, the brakes are the likely cause. That usually means worn pads and uneven rotors, not tires.

A pull instead of a shake

If the car drifts to one side on a straight road, or the steering wheel sits off center, that points to alignment. If it pulls only while you brake, the brakes are the more likely cause.

A wobble at low speed

An imbalance mostly shows at highway speed. A wobble you can feel at parking lot speeds is less typical of balance and more likely a bent wheel or a damaged tire. Have that looked at soon.

Still there after balancing

If a fresh balance does not fix it, the cause can be a bent wheel, a tire that is out of round, worn suspension parts, or the brakes. Those take a closer look.

Symptom, likely cause and service

We do computer wheel balancing, four-wheel alignment and brake inspections in the same shop. If you are not sure which one you need, tell us what you feel and when, and we will track it down.

Brakes: pads, rotors and inspection

Wheel alignment