Tires normally need balanced when they cause your vehicle to shake or vibrate. Balancing is achieved by positioning weights on the wheel to counterbalance heavy spots on the wheel-and-tire assembly.
Balanced tires are essential for a smooth ride and long tire wear. Tires are out of balance when one section is heavier than the others. In today's modern vehicles, vibrations can be felt at the slightest imbalance. As little as half an ounce of imbalanced weight can effect vehicle performance.
Dynamic Balance, also known as spin balancing, is used when there is unequal weight on one or both sides of the tire's centerline creating a side-to-side wobble. A dynamic balance spins the wheel and tire on a balancer to determin the location and amount of weight needed to correct the imbalance.
Proper wheel alignment is crucial for getting the most wear and performance from your tires. Wheel alignments adjust a vehicle's suspension so the wheels are positioned correctly relative to the vehicle's frame. This adjustment maximizes the life of your tires and prevents your car from veering left or right when traveling on a straight level road.
Vehicles become unaligned when the suspension gets knocked from off its specified location. Alignment problems can be caused by suspension wear due to age, potholes, curbs, or any suspension jarring. If a vehicle has been lifted or lowered, it may also need an alignment.
Signs you might need an alignment:
- Your car pulls or drifts away from a straight line
- You have rapid or uneven tire wear
- The spokes of your steering wheel are off to one side while driving on a straight and level road
Wheel alignments involve adjusting the three major alignment parameters: Camber, Caster, and Toe.
Camber is the angle of the wheel measured in degrees when viewed from the front of the vehicle. Camber is measured as positive if the top of the wheel is leaning out from the center of the car. If the top of the wheel is leaning in, then the camber is measured negatively. When the camber is out of alignment, your tire's tread will wear unevenly on the side. If your car has a pulling problem, the camber may be different on one side of your vehicle from the other. When one side of your vehicle has a positive camber, your car will pull to that side. On most moder front-wheel drive vehicles, the camber is not adjustable.
As you turn the steering wheel of a car, the front wheels turn on a pivot attached to the suspension system. The caster is the angle the steering pivot axis is tilted as viewed from the side of the car. If the top of the pivot is leaning toward the back of the vehicle, then the caster is positive. If the top of the pivot is tilted toward the front of the automobile, then the caster is negative. Caster is affected by vehicle height. If a vehicle is raised or lowered, the caster will shift due to suspension changes. Issues associated with caster problems include cars pulling to the side, or heavy or light steering. On many front-wheel drive vehicles caster cannot be adjusted.
Toe is measured by determining how much the front and rear wheels are turned in or out from a straight on position. When the wheels are turned in, they are considered toe-in and are positive. If the wheels are turned out, they are toe-out and are negative. When toe is out of alignment, it affects tire wear, straight-line stability and corner handling. Toe is adjustable on the front wheels of all vehicles and on the rear wheels of most automobiles.
Tire rotation is essential for improving tire life. Rotating tires on a regular basis improves even wear across the entire tread pattern. Before rotating tires, review your vehicle owner's manual for rotation recommendations. If no rotation period is listed, rotate your tires at least every 6,000 miles, or sooner, depending on tire wear.
Periodic tire rotation is important for tire maintenance. Tires will wear unevenly without rotation, leading to varying tread life and reduced vehicle performance. As a result, tires will wear out in pairs. Replacing tires two at a time hurts vehicle performance. With rotation, you can change your tire pattern so the wear is consistent throughout the whole set. When tires are replaced in sets of four, you improve your vehicle's handling balance and traction.
Rotating tires from front to back and side-to-side can reduce irregular wear. There are specific circumstances where standard tire rotation is not an option. Never include an emergency spare in a tire rotation. When using a full sized spare, place the tire in the right rear position. Tires with an assymetrical or unidirectional tread design have to be rotated directionally. Some vehicles also use different sized tires on the front and rear axels. Be sure to review your owner's manual to find your vehicle's best pattern for rotation.