Check out the Four-Wheel String Alignment System! Camber specs are set so that when a vehicle is at highway speed, the camber is at the optimal setting for minimum tire wear. It is up to a good wheel alignment technician to determine the cause. PMD Products Pair Wheel Alignment Turntable Turn Plates 10,000 Pounds Capacity w/Transition Bridge and Thrust Block. Toe-out on turns is measured by the turning angle gauges (turn plates) that are a part of every wheel alignment machine. Scrub radius is the distance between where the SAI intersects the ground and the center of the tire. The method is commonly known as "stringing" a car and it is simple, easy to understand and the more detail oriented you are the more precise it can be. While included angle problems will affect the scrub radius, it is not the only thing that will affect it. Front & Rear Wheel Alignment: For vehicles with adjustable rear suspension, all four wheels are aligned to the geometric centre of the vehicle, ensuring that the vehicle tracks straight ahead and … During a 4-wheel alignment, one of Firestone Complete Auto Care's ASE-certified automotive technicians will use state-of-the-art computerized technology to measure the camber, caster and toe. Steering center is simply the fact that the steering wheel is centered when the vehicle is traveling down a straight and level road. SmartStrings 4 Wheel Toe Alignment System Best and most universal way to quickly perform accurate four-wheel alignments on virtually any car anywhere. If the thrust angle is not zero, then the vehicle will "dog track" and the steering wheel will not be centered. Shop today! What’s the Difference Between Toe, Camber, and Caster? Camber is the angle of the wheel, measured in degrees, when viewed from the front of the vehicle. If it is not the same, then something is bent, most likely the steering knuckle. Most roads are crowned to allow for water drainage, and unless you drive in England, Japan or another country where they drive on the wrong (sorry) left side of the road, you usually drive on the right side of the crown. By clicking Sign Up, you agree to the  Terms of Use. This arm allows the inside wheel to turn sharper than the outside wheel. If the caster is equal but too negative, the steering will be light and the vehicle will wander and be difficult to keep in a straight line. I got the alignment done on my 92 Honda Prelude 4ws si exactly a year ago and when i just changed over to my snow tires i noticed my summer tires had pretty bad cupping on the inside of the tread on the rear tires. The purpose of these adjustments is maximum tire life and a vehicle that tracks straight and true when driving along a straight and level road. This type of tire wear is called a saw-tooth wear pattern as shown in this illustration. Inspect steering and suspension system, including tyre condition and air pressure. For more information on this see Steering Center and Thrust angle. It is important to note that the only symptom of weak coil springs is a sag in the riding height. Whatever you use, just make sure they are stable, heavy enough to keep good tension on the string yet light enough to move around relatively easily. Smart String 11410 4 Wheel Toe Alignment System . Laser String II simulates traditional three string alignment method used by racers but adds a third dimension in the vertical axis. Begin by placing your car in a level area of your shop with the suspension set up so that it is sitting at ride height. Park your car on a flat, level surface. Wheel rim run-out compensation is taken into account, which gives accurate and repeatable readings. Because of this, if the SAI is different from side to side, it will cause a pull at very slow speeds. This can definitely be true when it comes to squaring your car, or checking the alignment of all four wheels. Correcting rear axle or toe alignment is necessary to eliminate the thrust angle. If there is a difference in camber, then the left wheel should be more positive than the right wheel. SAI is also referred to as KPI (King Pin Inclination) on trucks and old cars with king pins instead of ball joints. If the sharp edges of the tread sections are pointing to the center of the car, then there is too much toe-in. That’s a big hit to anybody’s wallet. This angle, when added to the camber to form the Included Angle (see below) causes the vehicle to lift slightly when you turn the wheel away from a straight ahead position. Position the two jackstands so that the string runs along the side of the car, between 12 and 24 inches away and at a height at the middle of the wheel hubs or below. Wheel Alignment and Balance – … Assuming that the steering wheel stays in the same position when you let go of the wheel (in other words, the car is not pulling), then steering center is controlled by the front and rear toe settings. Toe-in means that the fronts of the tires are closer to each other than the rears. Another string is placed on the opposite side of the car, but instead of squaring it off the tire on that side, it's aligned off of the first string so that they are parallel. When the wheel is behind the pivot at the point where it contacts the ground, it is in positive caster. Just like a shopping cart caster, the wheel is forced behind the pivot allowing the vehicle to track in a straight line. That is what happens when a car has the caster set too far negative. Caster has little affect on tire wear. Because of this, specifications are determined for a vehicle that is not moving based on the toe being at zero when the vehicle is at highway speed. Write down that measurement. For many years the trend has been to set the camber from zero to slightly positive to offset vehicle loading, however the current trend is to slightly negative settings to increase vehicle stability and improve handling. Money by lowering fuel consumption between where the SAI is also referred to KPI... A few feet longer than the other wheel where doing mounted up set... Rearend is bent or has some toe built in, it is not.! Left wheel should be set first bringing the thrust angle as close to the center line and then the! Note that the rear toe should be set first bringing the thrust angle close. Car, or checking the alignment is performed traditional three String alignment method used by racers but adds third... 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