- Home
- Automotive
- Car & Truck Front End Wheel Alignments De-Mystified
Car & Truck Front End Wheel Alignments De-Mystified
- By Tommy I Vestore
- Published 31 January 2012
- Automotive
- Unrated
Your car seems to pull to one side of the road or another while driving down the street or road. Your trusted mechanic or dealership service tech adviser “advises’ you that you may need a “front end wheel alignment”. Other than extracting precious cash from your wallet or bank debit or charge card what is a front and wheel alignment? As well what do the words, phrases and measurements that the mechanic or the mechanics helper explains detail to you mean – well at least of terms of your vehicle’s drivability and tire care and maintenance?
Wheel (sometimes referred to as tire) alignment or alignments generally refers to all of the angular relationships between the front suspension and steering components and your integrated car body, or in older automobiles “the frame”. Overall it can be said that five angles are manipulated by automotive designers and engineers to reach a balancing act and indeed a compromise between optimal tire life and lifetimes , gasoline fuel economy and in the end your road handling and driving safety. As a maxim it can be said that best overall fuel economy and tire life are achieved if the tires are perfectly upright as well as being in parallel stance to the overall direction of travel. However a car, Sports Utility Vehicle SUV or truck steers and handles better if its tires run at a slight angle. This does cause them to scuff along the pavement a bit as they roll, which does work to reduce tire life and fuel economy. Thus it can be said proper tire alignment to begin with is one big balancing trick.
“Camber” is the inward or outward tilt of the wheel, measured in degrees between the tire centerline and the vertical. To simplify the term “camber” to the average automobile owner simply put if the wheel tilts outward then camber is said to be “positive”; if it tilts inwards then the camber is “negative”.
“Caster” is the angle that the steering axle is offset from the vertical, measured from front to back. If the steering knuckle tilts towards the back, caster is said to be positive, and if it tilts towards the front the caster measurement is said to be negative.
“Steering Axis Inclination” is the angle that the steering angle is offset from vertical measured from side to side. If the upper ball joints are further inward than the lower ones, the wheels will straighten out if the steering wheel is released while the car is moving.
“Toe-in” means that the front edges of your wheels are closer together than the rear edges. Toe-in counteracts the tendency of front wheels to “toe out” under power on older model rear wheel drives and trucks.
When the car is driving at highway speeds, toe-in generally disappears and the wheels thus straighten out. Whereas on current front wheel drive vehicles (which is now the norm for most passenger cars and some trucks), “Toe-out” is sometimes used itself to counteract the built-in tendency to toe in under power. Some toe-out on turns is necessary for all cars because the inner wheel must turn at a sharper angle than outer wheels.
Toe is adjustable on all cars. Caster and camber are adjustable on most suspension designs.
All of the above being said , if you find that your car pulls to one side of the road or another when driving , if you mightily hit a curb or gone over or even fallen into a deep rut in a road construction area then you might well be a candidate for a good front end wheel alignment. Especially now with front wheel drive vehicles having your front end wheels aligned properly is crucial. This is important for overall maintenance, better tire life and safety. In addition some automotive maintenance experts might say that it protects and preserves your front end drive components and transmission from expensive major repairs. Front-end alignments are done with a highly specialized and expensive machine. Not all auto repair facilities and certainly not your local backyard garage auto mechanic all have such a machine. Simply ask around at your mechanic or local auto parts outlets who they recommend for front end wheel alignments in your area. It’s that simple.
Wheel (sometimes referred to as tire) alignment or alignments generally refers to all of the angular relationships between the front suspension and steering components and your integrated car body, or in older automobiles “the frame”. Overall it can be said that five angles are manipulated by automotive designers and engineers to reach a balancing act and indeed a compromise between optimal tire life and lifetimes , gasoline fuel economy and in the end your road handling and driving safety. As a maxim it can be said that best overall fuel economy and tire life are achieved if the tires are perfectly upright as well as being in parallel stance to the overall direction of travel. However a car, Sports Utility Vehicle SUV or truck steers and handles better if its tires run at a slight angle. This does cause them to scuff along the pavement a bit as they roll, which does work to reduce tire life and fuel economy. Thus it can be said proper tire alignment to begin with is one big balancing trick.
“Camber” is the inward or outward tilt of the wheel, measured in degrees between the tire centerline and the vertical. To simplify the term “camber” to the average automobile owner simply put if the wheel tilts outward then camber is said to be “positive”; if it tilts inwards then the camber is “negative”.
“Caster” is the angle that the steering axle is offset from the vertical, measured from front to back. If the steering knuckle tilts towards the back, caster is said to be positive, and if it tilts towards the front the caster measurement is said to be negative.
“Steering Axis Inclination” is the angle that the steering angle is offset from vertical measured from side to side. If the upper ball joints are further inward than the lower ones, the wheels will straighten out if the steering wheel is released while the car is moving.
“Toe-in” means that the front edges of your wheels are closer together than the rear edges. Toe-in counteracts the tendency of front wheels to “toe out” under power on older model rear wheel drives and trucks.
When the car is driving at highway speeds, toe-in generally disappears and the wheels thus straighten out. Whereas on current front wheel drive vehicles (which is now the norm for most passenger cars and some trucks), “Toe-out” is sometimes used itself to counteract the built-in tendency to toe in under power. Some toe-out on turns is necessary for all cars because the inner wheel must turn at a sharper angle than outer wheels.
Toe is adjustable on all cars. Caster and camber are adjustable on most suspension designs.
All of the above being said , if you find that your car pulls to one side of the road or another when driving , if you mightily hit a curb or gone over or even fallen into a deep rut in a road construction area then you might well be a candidate for a good front end wheel alignment. Especially now with front wheel drive vehicles having your front end wheels aligned properly is crucial. This is important for overall maintenance, better tire life and safety. In addition some automotive maintenance experts might say that it protects and preserves your front end drive components and transmission from expensive major repairs. Front-end alignments are done with a highly specialized and expensive machine. Not all auto repair facilities and certainly not your local backyard garage auto mechanic all have such a machine. Simply ask around at your mechanic or local auto parts outlets who they recommend for front end wheel alignments in your area. It’s that simple.
Tommy I Vestore
Tommy I Vestore Coquitlam BC GM Auto Service One of British Columbia's Leading General Motors Dealers BC Lottery Winners Vancouver Auto Truck Traders
View all articles by Tommy I Vestore