What is an Alignment?
And why is it important for more than a straight steering wheel
Why is your car out of alignment?
Every vehicle starts its life rolling out of a factory with the “perfect” alignment. Over time, as you hit bumps and curbs, suspension wears or breaks in, or your tires wear, the alignment slowly works its way out of spec.
While I can’t teach you how to do an alignment at home (equipment needed is large and expensive), we can make sure you have enough knowledge on what the terms and numbers mean, so you won’t get taken for a ride the next time you hit a shop.
What are Camber, Caster, and Toe?
So you roll into your local tire shop and ask for a free alignment check. Almost any reputable shop or dealership will offer an alignment check for free. They are going to take around 5-15 minutes to set your car up on the rack and take the initial measurements on a machine like the one pictured above.
The alignment machine uses laser and sensors attached to your rims or tires to measure all the angles your tires are sitting at, in relation to a flat surface. Once the initial check is done you will receive a sheet like the one below.
I’m leaving this picture large because it shows everything we will discuss in this article.
If you are unsure of the shops in your area feel free to send me a picture of this sheet. I will explain the numbers further and let you know if you actually need an alignment. Comment below, Tweet or DM me @BowTiedGreaseMonkey
The center of each of these bars shown on the sheet is the specification for your particular vehicle. Manufacturers put newly designed vehicles through all types of road tests with different setups and look for what they deem ideal ride quality, comfort, and performance.
Camber and its Effects
Camber is how your tire sits vertically, shown at the top of the measurements for each tire.
Negative Camber is when the top of the tire leans towards the inside. Positive is the top of the tire leaning out.
Going too far in either direction will result in a terrible drive, and wear the inside or outside of tires far quicker.
Positive camber is seen on vehicles designed more for comfort and a smooth ride, while negative camber allows for better cornering in more performance-based models.
Cross camber, though not often shown on printouts (it can be if you ask specifically), is the difference between the camber of tires on opposite sides. A large difference in camber settings between tires on a single axle can cause vehicle pull, as can having one side set negative while the other is set positive.
Caster and its Workings
Caster is the next measurement you see on the alignment sheet. Caster is the line drawn through the top and bottom of your steering pivot point. Generally, your steering pivot point is the top of your front strut to where the wheel connects to the hub.
Caster aids in staying straight while driving without added effort from the driver, and steering wheel returnability when coming out of turns. Think about when you take a turn and as you come out of it the vehicle sorta pulls your wheel back straight. That’s caster doing its job.
Caster is rarely a needed adjustment on cars that haven’t been in an accident, but trucks and SUVs often have a specific adjustment for the caster.
On a front-wheel-drive vehicle, caster will not cause a pull to one side or another unless major damage has happened.
On a rear-wheel-drive vehicle, the caster will cause a pull to whichever side has less caster. For example on the sheet at the top, this vehicle’s caster would cause it to pull right, was it rear-wheel-drive.
On rear-wheel-drive vehicles, you will want the front left tire to be about .25-.5 degrees less, which will work against the crown of the road to track your vehicle straight. Caster is often the cause of a pull on pickup trucks.
Toe Settings
Toe is how your tires are turned in or out. The most obvious symptom of this adjustment being off is a crooked steering wheel while the car drives straight.
Toe is also the most common adjustment that will fall out of specification.
Nearly every vehicle will have a slight toe-in. This will keep your vehicle from wandering at higher speeds and understeering.
Often as the toe gets out of alignment, one side will get further out and cause your steering wheel to sit crooked. Excessive toe in either direction can cause tire wear in diagonals as your tires fight to take you straight while the suspension is aiming your tires elsewhere.
Additional Notes
Tire Pressure and wear can affect alignment as well, which is why you hear people recommend an alignment with new tires.
Leaving one or more tires underinflated can cause the vehicle to pull.
Thrust angle is the relationship between your front tires and rear tires. This number should never be in the red unless serious accident damage has occurred.
Conclusion
Now that you have a better understanding of your vehicle’s alignment, which you should have looked at yearly, hopefully, you can make the correct call when they hand you that sheet. Check out the numbers yourself and see if you think an alignment is required. Be sure to let me know how it goes.
As I mentioned earlier, comments, tweets, and DMs are always open. I’m glad to take a peek and give you a professional opinion before you spend your hard-earned money.
Thank you...informative post!
Great content. Thanks for your explanation.