Your vehicle is designed to travel straight on the road and not wander from side to side. The wheel alignment on the car has a significant effect on how the vehicle handles and can change how parts on the vehicle wear over time.
Problems with wheel alignment most affect the front of the car because the steering axle has more moving parts than the rear-drive axle on most vehicles. Ball joints, tie rods, and steering links on the front axle can all wear down over time, and if they are not replaced, the alignment will change, causing damage to the tires and other parts of the system.
A worn ball joint can allow the tie to tip in or out and create a condition that wears the tread along the tire's edge very rapidly. The tire does not have as much rubber along the edges, so once it starts to wear, the rubber can scuff off until the steel under it shows and creates a dangerous situation.
Steering links and tie rods often affect the tires by pulling the front of the tires closer together or pushing them further part, causing a condition called toe-in or toe-out. Both of these can cause the vehicle to be difficult to drive, but all of these conditions can be repaired, and the wheel alignment can be corrected by a qualified repair technician at a garage that has an alignment rack.
Aligning The Wheels
When you take your car in for a wheel alignment, the tech will inspect the car for signs that might indicate what, if anything, is out of alignment. The vehicle is then put on the alignment rack, and a receiver is placed on each wheel.
The computer system on the rack uses the sensors on the wheels to determine the tire's position and the proximity to the other tires on the vehicle. The system will then determine if the alignment is out of spec and which wheel or wheels need attention.
While the computer can tell the technician which wheel is out of alignment, it does not indicate why. The tech will have to get under the car and look at all the parts that could be worn to determine what needs to be replaced. Sometimes the parts need to be adjusted, and other times a part needs to be replaced before the alignment is rerun.
Once the computer shows the alignment is back to factory specifications, the tech will go over the alignment results with you and let you know if there is any other work that needs to be done to make the vehicle safe to drive.