When do tires need to be balanced?

Why do tires need balancing? When a tire is installed on a rim, there is always some weight imbalance, or one side of the assembled wheel is a bit heavier. This imbalance will cause a vibration when driving at higher speeds. For this reason, each tire is balanced after it's installed on the rim. To balance a tire, the weight of the imbalance is measured and the same amount of weight is attached to the wheel on the opposite side from the heavy spot.
Balanced tire Balanced tire (wheel).
When a new car is assembled, tires are balanced at the factory. Tires are also balanced when a mechanic at a dealership or auto repair shop replaces your tires. A tire is also re-balanced whenever it is removed from the rim and reinstalled back, for example, to patch up a leak.

When do tires need to be balanced? Car makers don't include tire balancing in the maintenance schedule. Your mechanic may recommend balancing your tires if you feel a vibration or as a preventative maintenance. Balancing tires won't be much of a benefit if you don't feel any vibration when driving on the highway.
What are the signs of tires that are out of balance? The most common symptom of an unbalanced tire is a vibration at highway speeds. Of course, there are many problems that can cause vibrations in a car, including faulty CV axles, wheel hubs, a propeller shaft and other drivetrain and suspension components.
Technician balancing a tire Technician balances tire on a tire balancing machine.
However, issues with tires and rims are still responsible for 85-90 percent of vibration complaints. A vibration that is caused by issues with tires or rims feels more pronounced when driving steady at speeds between 50 and 70 mph.

Can unbalanced tires cause vibration when braking? If there is no vibration when driving, but you feel it when braking, then it's possible that it could be caused by issues with brake rotors; read more: Why does the steering wheel shake when braking at high speed?.

How do mechanics balance tires? Mechanics use a tire balancing machine (in the photo) to balance tires. An assembled wheel is pumped to the specified air pressure and secured on the balancing machine shaft. The machine spins the wheel for a few seconds and stops. It calculates and shows on the screen how many ounces or grams need to be added and where to place the weights. A mechanic attaches clip-on or stick-on weights to the rim in places where indicated.

Do tires go out of balance over time? A tire might go out of balance due to uneven wear or if one of the wheel weights fall off. For example, this often happens when a rim is scraped against the curb. A wheel might also go out of balance if the rim is bent (even slightly) after hitting a large pothole.

Normally, if you check all tires on a tire balancing machine after one or two years of driving without incidents, you might find that one or two tires are slightly off balance.

Do all 4 tires need to be balanced? If there is a vibration issue, all 4 tires are typically balanced at the same time. The reason is that it's hard to tell which tire is the cause of the vibration. In cases where the repair is done to only one tire (e.g. puncture repair), only that tire needs to be re-balanced.

How much does it cost to get your tires balanced? The price to balance four tires (wheels) vary between $60 and $120. It takes about 30-45 minutes to balance all four wheels.

What causes flat spots on tires? If the car is parked for several months without moving, especially in cold weather, tires might develop flat spots that will also result in a vibration when driving. Normally, tires warm up as you drive and the flat spots gradually disappear, however in worst cases, tires might need to be replaced. Read below how tires are checked for flat spots.

Can balancing tires fix all vibration concerns related to tires and rims? No, balancing tires on a regular tire balancing machine can only eliminate vibrations caused by weight imbalance. If a tire has flat spots or "hopping" up and down or wobbling side to side, or if the rim is bent, balancing the wheel will not eliminate the vibration completely. To check for this type of problem, request Road Force balancing.

What is Road Force balancing?

Hunter Road Force balancer Road Force balancer. Photo, courtesy of Hunter Engineering Company.
The Road Force tire balancer is more advanced. It's equipped with a roller that pushes on the tire tread to imitate the road force. This allows not only to check the weight imbalance but to measure the tire uniformity. The Road Force balancer can detect if the tire has flat spots or if it is out of round (hopping). In some cases, repositioning a tire on the rim using a Road Force balancer can solve some vibration issues. In other cases, a tire or rim (if damaged or bent) might need to be replaced.

Can an ice buildup on the wheels cause vibration? Yes, the vibration in the car is one of the most common complaints after a winter snow storm or frozen rain. The ice and snow sticks to the inside of the rims and creates imbalance. In most cases, the vibration goes away after the ice on the rims melts.

Should I balance my tires before an alignment? Wheel alignment and tire balancing are two completely different services. The wheel alignment involves checking and adjusting the angles between the wheels and the vehicle body (chassis).