I’m a long time show listener but new to the website (love both). I want to know everything I can about wheel alignment. Here are my questions to get the discussion started:
1- Please describe in detail the “alignment process”. I know it involves measuring and then possibly adjusting. But what is being measured? How is it being measured? What is being adjusted? How is it being adjusted? Does it involve only the fwd/reverse axis? Or does it include the up/down axis? Is it done with the wheels installed or removed?
2- What could cause a car to go “out of alignment”?
3- Are there any symptoms of misalignment other than uneven tire wear?
4- When should alignment be checked? Is there a standard time or mileage interval? Or is it only when new tires are installed? Or only when symptoms are observed? I never see alignment listed in any recommended maintenance schedule.
5- If one takes a car to get “aligned”, how can one be sure the proper work is performed?
6- I’ve found that some repair places are offering different “levels” of alignment. One level is guarenteed for 6 months, another for 1 year (for approx $50 more) and so on. Do you think the higher levels are worth the higher price?
I’m afraid that I mostly disagree with CapriRacer here. The first question might be a little broad, but the others are things that are good for a car owner to understand.
I’m no expert, but I assume the most common cause for a car to go out of alignment is all of the potholes and other bumps hit by the car over time, especially the nasty ones. As for when to do an alignment, I suspect opinions here will vary. I do it each time I get new tires. One or more values are usually out-of-spec at that time for me. Some people wait for abnormal wear patterns to appear, but by then it’s kind of late. As for making sure the proper work is performed, I’ve always been given printouts of the values before and after the alignment, although of course that doesn’t prove that everything was done correctly.
I think the OP raises some good questions here. I know a few people who are too cheap to get a proper alignment done then they b$&ch because their car grinds up tires within a year.
The car is put on a rack with devices clamped to the wheels that measure how the wheels are aligned. There are several adjustments in the suspension and steering systems that can be adjusted so that they are put in the correct alignment and to center the steering wheel when one is driving straight. Hitting bad potholes and curbs will knock it out of alignment, and usually when a tie rod end or a ball joint is replaced, it is a good idea to have the alignment checked. Whacking a curb real good will probably bend a wheel or a suspension part.
Finding a shop that does a good job is like finding a shop that does a good job on anything else. You may have to do a bit of homework. I am skeptical of “lifetime” alignments and different “levels” of work. It takes time and effort to get the car on the rack and get everything set up to check it, and it is either done right or not. Find a shop that does a good job and pay for it when needed.
I just went through a few headaches back in October when trying to get my wife’s Chevy Blazer aligned. All alignment shops spell alignment the same way on the sign outside but the work they do inside is completely different from each other. If an alignment doesn’t feel right…feel free to take it back to the shop. If it doesn’t feel right after the second visit then take the vehicle to another shop for a second opinion. You’ll be glad you did. I was. It turned out that the first shop did a lot of “shortcuts” on the Blazer. Shortcuts are the last thing you need when it comes to your steering.
The alignment process is done by measuring angles. You want the wheels to be approximately 90 degrees with respect to the road surface. Due to the action of the suspension this angle may not be exactly set to 90 degrees. Also there is a caster angle that forces the front wheels to self return due to the force of the car against the wheels. Finally there is toe-in/toe-out that makes sure that the wheels do not scrub sideways as they roll down the road. The reason some toe-in is adjusted in is that the front of the car lifts a little at speed allowing near zero toe-in.
The alignment is done with the wheels on the car, the car at its usual driving weight and weight distribution on a flat surface
On fully independent suspension cars, i.e. no solid rear axle, all four wheels have to be aligned to the manufacturer specified angles.
The adjustments are as varied as there are cars. Cars with McPherson struts adjust the camber by loosening the bolts attaching the struts to the knuckles, Double A arm cars usually have a way to adjust the in/out of the attachment axles. Solid beam axles are bent. Caster angles are usually not adjustable on strut cars. A-arm suspenses are adjusted by differential adjustments of the attachment axles. Tow-in is adjusted by adjustable sleeves attaching the tie rod or rack to the tie rod ends.
As others have said what causes wheels to go out of alignment are tire hits – pot holes, curb strikes, parking stoppers, accidents, parts replacements, etc. Also there is wear of components compression of bushing, and sag of springs.
The symptoms of poor alignment are fast tire wear, uneven tire wear, pulling to one side, shimmy, steering wheel not centered, slop in the steering box or rack, dog tracking (front wheels not tracking the rear wheels), and shaking.
You should get an alignment when you get your tires replaced expecially if the tire wear was uneven. Also an alignment should be done if a suspension part is replaced like a rack, bushing, struts, tie rod end, etc. If the car is involved in an accident it should be aligned unless the body shop indicates that no structural damaage was done. You should consider a realignment if a hard wheel strike occurs. If you inspect the tires on a regular basis you can catch uneven wear and realign before the tires become unuseable. Also if the car is pulling to one side an alignment is appropriate.
You really cannot know for sure that an alligment has been done correctly other than if there is no tire squeeling, the steering wheel self centers well after a turn, the steering wheel is centered when you drive down the road, and the there is not pulling. You could also see if there are any tood marks on the adjustment bolts.
The guarrantee of the allignment is only a selling tool. All they are saying is that if you come back withinn the correct period they will recheck the angles and adjust as necessary. They probably will not realign if you come it after a part replacement or signs of damage to the suspension.
I generally do not like getting an alignment unless there is a good reason. The only two reasons I can think of is that the vehicle does not steer or track correctly, i.e pulls to one side or the steering is too sensitive and the vehicle is hard to keep in a straight line, or the tires wear out faster than they should and/or show an unusual wear pattern.
I also don’t like rotating tires as often as a lot of people do. A slight misalignment would be hidden because of too frequent rotation. Sometimes it takes awhile for an odd wear pattern to show up.
Unless you have your own alignment equipment or know how to build an alignment jig, the only way to tell if the alignment you paid for is any good is time. If the tires still look good after a year, then the alignment was done right.