Wheel alignment and wheel balancing are two totally different things, but many people often get them confused. To put it simply, wheel alignment consists of adjusting the angles of the wheels so that they are perpendicular to the ground and parallel to each other. The purpose of these adjustments is maximum tire life and a vehicle that tracks straight and true when driving along a straight and level road. Wheel balancing, on the other hand, allows the tires and wheels to spin without causing any vibrations. This is accomplished by checking for any heavy spots on the wheel-tire combination and compensating for it by placing a measured lead weight on the opposite site of the wheel from where the heavy spot is.
The symptoms of a car that is out of alignment are:
- Uneven or rapid tire wear
- Pulling or drifting away from a straight line
- Wandering on a straight level road
- Spokes of the steering wheel off to one side while driving on a straight and level road.
The symptoms of a wheel that is out of balance are:
- Vibration in the steering wheel at certain highway speeds.
- Vibration in the seat or floorboard at certain highway speeds.
- Scalloped or cupped wear pattern on the tires
Out-of-balance tires will cause a car to vibrate at certain speeds, usually between 50 and 70 mph. A tire is out of balance when one section of the tire is heavier than the others. To balance a wheel, the technician will mount it on a balancing machine which spins the wheel to locate the heavier part. He will then compensate for the heavy part by attaching a lead weight on the opposite side. Many people are pleasantly surprised at how smooth their car drives after balancing all four wheels.
