Four Wheel Alignment

"Alignment" can be a scary word for motorists.

The term, especially "four wheel alignment" conjures up visions of inscrutable equipment and highly specialized automotive service. Even drivers who understand the term "tuneup" are often mystified by "alignment." And the new trend toward four wheel alignment can appear to be an expensive service for which the unwary motorist seems to be paying extra.

Mike Jones, Perfect Circle Chassis Marketing Specialist, advises that alignment is recommended for today's cars and light trucks in at least four situations:

1. When you buy new tires. "In fact," says Jones, "if your old tires wore unevenly, bad alignment could be the reason they had to be replaced, and the same thing could happen quickly to your brand-new tires!"

2. When you have a rack & pinion steering unit or certain other steering parts in your car replaced, alignment is necessary;

3. When certain warning signs appear on your car, indicating that alignment is needed;

4. Or about every 30,000 miles, whether warning signs appear or not.

Just What Is An Alignment

"Basically, alignment is making sure the wheels are operating parallel with one another, and that the tires meet the road at the correct angle. Wheel alignment is much simpler than most people think," explains Perfect Circle's Jones. "It is simply adjusting the relationship between the suspension and steering components, the wheels, and the frame of the vehicle."

"Carmakers recommend certain measurement specifications for each of these angles on every one of their vehicles. When the angles are all as specified, the car or truck is properly aligned, and the best possible compromise has been achieved among minimum rolling friction, maximum tire mileage, stability of the car on the road, and steering control for the driver."

"Everyday road shock and general wear and tear can knock some of these angles out of spec. When that happens, control of the vehicle may be threatened, and the tires may begin to wear unevenly and rapidly. The car needs to be `realigned,' to have all the proper angles restored," Jones concluded.

Warning Signs Are Easy To Spot

The warning signs suggesting the need for alignment are easy to spot, says Jones. They include:

• Unusual tire wear. Look closely at all four of your tires. If one or more of them demonstrate excessive wear on one side, or wear in a cupped, scalloped or diagonal stripe pattern at edges or across the tread, or uneven wear but with "feathered" edges on the treads, an alignment could be needed.
• Unusual steering feel. If the steering feels stiffer than it used to, or if the wheel does not return to the center position when released, or if the car feels skittish and like it is riding "on tip-toes", your wheels may be out of alignment.
• If the steering wheel is cocked to one side when the front wheels are pointing straight ahead, an alignment is almost certainly needed.
• While driving, if the car wants to pull to one side, tends to wander or weave, or is subject to front end "shimmy", you should have the alignment checked immediately.
• Or if your car wants to move "crab-like" on the road, with the rear end cocked off to one side while moving straight ahead, you're a top candidate for serious alignment.
• There are three basic wheel angles which determine whether a vehicle is properly aligned and goes where it is pointed. Not every angle applies to every wheel, and not all angles are adjustable on all cars, but the three angles must be set properly for the alignment to be correct:
• Camber is simply the inward or outward tilt of a wheel compared to a vertical line.
• Caster is the degree that the car's steering axis is tilted forward or backward from the vertical as viewed from the side of the car.
• Toe refers to the directions in which two wheels point relative to each other. "Toe-in" means the wheels point toward each other in a "pigeon-toed" stance; toe-out means the wheels point away from each other.

Four-wheel alignment is the standard service today, and it is essential on vehicles with front wheel drive (FWD) and independent rear suspension. The rear wheels should follow the fronts in a parallel path. If the rear wheels are pointed in a slightly different direction, they cause a condition called "rear axle steer," which can affect tire wear and the vehicle's stability.

What Happens During An Alignment?

Before an alignment, the technician will begin with a thorough inspection of the entire undercar, including steering linkage, suspension parts, wheels and tires, and the vehicle's frame and ride height. He's looking for parts that are loose, bent or near failure.

Once this inspection is complete, your car will be driven onto the alignment machine. The technician will check and adjust, in order, camber, caster and finally toe, beginning with the rear wheels. (Remember, not all wheels are adjustable on all vehicles.) He may use regular wrenches and variety of specialized tools and devices, manufactured by automotive suppliers such as Perfect Circle, to make the necessary adjustments. The tools can include:

• Alignment shims, half-shims and wedges
• Eccentric bolts and cams
• Adjustable and non-adjustable bushings
• Offset control arm shafts.

Some Vehicles Have Special Problems

Perfect Circle's Jones pinpointed several vehicles whose designs require special alignment solutions. Perfect Circle has created replacement parts that address alignment challenges with these vehicles:

1. Ford Tempo and Taurus, Mercury Topaz and Sable, Lincoln Continental. These very popular FWD vehicles have a tendency late in life to develop rear wheel misalignment, resulting in tire wear and handling difficulties. Perfect Circle has developed a line of eccentric camber/toe bushings, which service dealers can insert in the suspension to adjust camber and toe and bring them back to factory specifications.

2. GM "A" and "X" car, '88-89 GM 2WD and 4WD pickups, and early Chrysler "H" and "P" cars. Again, replacement cam bolt kits allow alignment adjustments to bring worn steering back to factory specs.

Future Alignment?

"We are entering an age of rapid change in suspension/steering design, after many years without significant changes," observes Perfect Circle's Jones.

"The majority of cars sold in this country today are front wheel drive. Most of these cars are dependent on proper alignment at all four wheels to operate safely and achieve acceptable tire wear. Believe me, the cost of a four wheel alignment is well worth it in vehicle handling alone. And it could save you several times its cost in reduced tire wear," Jones concluded.

Call William at Whitman's Serice Center to learn more about 4-wheel alignments. HOME ~TIRES~~ MAP~~ ALIGNMENT~~ FUEL INJECTION CLEANING~~ BATTERY~~ SHOCKS & STRUTS~~ BRAKES~   Whitman's Service Center 41133 HIGHWAY 195 HALEYVILLE, ALABAMA 35565