Car Wheel Alignment

Wheel alignment means adjusting the angles of the wheels of a car in a way that they are perpendicular to the ground as well as parallel to one another.  The idea behind car wheel alignment is enhancing the life of the tires as well as ensuring that the vehicle runs straight when being driven along a straight and even road. Whenever the wheel alignment is absent in a vehicle, it causes vibrations at highway speeds that can be felt in the steering wheel or the seat.

 

The absence of wheel alignment will also cause the vehicle to drift to one side, depending upon which of the tires are not aligned. The driver will constantly have to steer the car to the other side in order to keep it going in a straight line. This is not only bound to tire out the driver during long journeys, but also cause excessive wear and tear of the tires.    

 

Camber, Caster and Toe are the three factors that determine whether the tires or wheels of the car or any other vehicle are properly aligned or not. When the wheels are not aligned, they cause specific problems mentioned below.  

 

The titling of the wheels or the tires from the vertical, when seen from the front of the car is called the chamber. Chamber is positive (+) if you find that the wheels are tilting outwards at the top. But when the wheels of the car is tilting inwards at the top, then the chamber is said to be negative (-). This tilt is measured in degrees from the vertical point. How the chamber is set determines the wearing of the tires and the directional control.   

 

Excessive positive camber (outwards tilting of the wheel at the top) causes early wear and tear on the outside portion of the tire. It also results in too much wear on the suspension parts. On the other hand, excessive negative camber causes early wear on the inside regions of the tire apart from causing too much wear on the suspension parts. Imbalanced side-to-side camber of 1° or more will make the car pull or head to the side experiencing most positive camber.

 

The topmost tilting of the steering axis either infront or backward when seen from the side of the car is called caster. When there is backward tilting, it is termed positive (+) whereas the forward one is termed negative (-). Caster affects the directional control of the steering wheel, but does not influence wear of the tires. Since caster is influenced by the height of the vehicle, it is vital to keep the body at its original height. A weak, sagging rear and excessive loading on the vehicle are factors that affect the caster.       

 

Whenever the back of a car or any other vehicle is lower then its chosen trim height, then the front suspension shifts to a more positive caster (tilts backward). On the contrary if the back portion of the car or vehicle is higher than its chosen height, then the front suspension will shift to a less positive caster. In this position, the steering may turn to be a bit moody during high speeds.

 

Also the wheel returnability may get reduced while coming out of a turn. Yet another case could be that one wheel may have more positive caster than another. Under such circumstance, the wheel will pull towards the center of the vehicle causing it to head to one side with the minimum positive caster.

 

The measurement of how much the front and / or rear wheels are tilted inwards or outwards from a straight-ahead position is called the toe. The toe is positive (+) when the wheels of the vehicles are tilted inwards and negative (-), when the wheels are tilted outwards. The right amount of toe is just a fraction of a degree.