Getting your wheels aligned

The more I hear about it, the worse it gets. They pull your vehicle in, give you a nice, fancy print out to scare you that your alignment isn't perfect and BAM, $100 alignment charge. Maybe that particular dealership isn't trying to scam people but I can see how a machine like that can easily be mis-used to sell work that isn't needed.

 

About 5 years ago I worked as an alignment tech for Tire Pros in thousand oaks. I worked my way up and apprenticed under an ase master tech. He did alignments the way they were supposed to be done and I saw the difference between his work and that of my co workers. Its really easy to mess up an alignment and unless you know what you are doing, the numbers you get after the alignment are incorrect.

Alignment 101 - You setup the car on the alignment rack. Attach the sensors to the wheels. Roll the car back and forth, turn the wheel side to side, and the computer registers all the specs. That gives you your base numbers. When adjusting alignment you go back to front. Our trucks have a solid axle so you won't do anything to the rear (unless the truck is dog tracking pretty bad then you can drop the axle and shim it). But for 99% of cases you just do the front. You setup camber and caster simultaneously via upper and lower control arms. We have two eccentric bolts on each arm. Move the bolts on each arm the same direction and you adjust camber; opposite direction to adjust caster. There are many variations that will get you within spec but that is not always enough. Higher caster will give you a more stable ride and usually I would try to max out caster with the right side slightly higher than the left to counter act the crown on most roads. The crown being the curvature of pavement to the right that will cause the vehicle to move right even with a perfect alignment. Camber adjustment will change caster so you want try to ball park these together.

Once that is done and you have your two readings where you want them you finish the alignment with the toe adjustment. If toe is far out of spec from a lift, it will change camber and possibly caster. So when I did adjustments that were way out of spec I would ballpark all three and then start over with a fresh set of readings to fine tune the adjustments.

Problems I have seen:

1) (common) You get your readings and adjust caster, camber and toe separately. If the alignment is way off then each adjustment may change the other two. So after the tech gets camber and caster into spec, he sets toe but now camber/caster has changed. Instead of going back and fixing them he moves the sensors with a slight touch to get the numbers in spec. If you ever see a tech touch the sensors after the initial reading then ask him to do the alignment again.

2) Some techs are lazy and will tell you that the eccentric cams are maxed out and there is no more adjustment possible. Maybe that's true but I've seen that many times the tech just doesn't know what he is doing and uses that as an excuse. Read up on how eccentric work and be able to identify a maxed out cam. Ask the tech to show you the maxed out cam while it is still on the rack.

3) After a major alignment sometimes the truck needs to roll a few feet so the suspension can level out. If the roller plates that the wheels sit on are old or not moving freely then they will cause resistance when adjusting the alignment. Thus the readings you get will be off once the suspension settles.

4) (also common) After the tech gets the alignment within spec he will tighten down the control arm cams and tire rod adjustments. After they are tight the numbers might change depending on if the tech allowed the adjustments to move at all. Some techs I have seen will print out the finished readings before tightening everything up. They do this because they know that the readings may change and they don't want to have to go back and fix it. Beware of them going back under the car after they printed out the final specs. They might say that it doesn't matter but It does and bringing your truck back in a week is a good way to verify this.

When I get alignments I always chat with the tech before the alignment. I ask him to get the caster maxed out with about .5º more on the right side. Usually he sees that I know more than most car owners and can't cut corners. Ill let him do his thing and unless I notice any of the three things above I will not say anything. Ill drive the car around for about a week and bring it back for a check. Most places offer a 6-12 month warranty on the alignment. I suggest you use it. Mention any problems you had (if any) and verify that the final readings were actually correct and not manipulated by any of the reasons stated above.

Not all alignment techs will do what I have listed above but many will. Alignments are an easy money maker for most shops and most people don't understand what to look for in a good alignment. Its your hard earned money so do your homework and be aware of what they are actually doing.

 

Good post! Thanks for the info.