Norfolk Alignment Services
Carmasters has updated our vehicle Alignment system. A few of the features are:
Video Speed Cameras Constantly Monitor Alignments, Providing Information at Every Step - The geoliner® 770 Mobile Imaging Wheel Aligner's advanced XD cameras and sophisticated monitoring algorithms find errors as they’re made, detecting problems with suspension stress and damage, rack, clamps, environment, and more - notifying users only when necessary, to save time and ensure accuracy on every alignment.
The vehicle selection process provides make/year/model selection and manual or scanner vehicle identification number (VIN) selection
Diagnostic alignment with “Compensate Warn Alert” intervention gets it right the first time
Highly accurate and reliable XD camera technology
We can perform alignments on most vehicles with:
- Tire diameter19"–39" (48.3cm–99.1cm)
- Track width48"–96" (121.9cm–243.8cm)
- Wheel base79"–180" (200.7cm–457.2cm)
Camber is the angle of the wheel, measured in degrees when viewed from the front of the vehicle. If the top of the wheel is leaning or tipped out from the center of the vehicle, then the camber is positive, if it's leaning tipped in at the top, then the camber is negative. If the camber is out of adjustment, it will cause tire wear on one side of the tire's tread. If the camber is too far negative, for instance, then the tire will wear on the inside of the tread.
Caster When you turn the steering wheel, the front wheels respond by turning on a pivot attached to the suspension system, pivot points can be combinations of a ball joint, strut at mount, king or pivot pin, depending on the model. Caster is the angle of this steering pivot, measured in degrees when viewed from the side of the vehicle. If the top of the pivot is leaning toward the rear of the vehicle, then the caster is positive if it is leaning toward the front, it is negative.
SAI is the measurement in degrees of the steering pivot line when viewed from the front of the vehicle. This angle, when added to the chamber to form the included angle (see below) causes the vehicle to lift slightly when you turn the wheel away from a straight-ahead position. This action uses the weight of the vehicle to cause the steering wheel to return to the center when you let go of it after making a turn. Because of this, if the SAI is different from side to side, it will cause a pull at very slow speeds. Carmasters alignment machine has a way to measure SAI; however, it is not separately adjustable. The most likely cause for SAI being out is bent parts which must be replaced to correct the condition. SAI is also referred to as KPI (King Pin Inclination) on trucks and old vehicles with kingpins instead of ball joints.
Riding height is measured, usually in inches, varies by model, but often measured from the rocker panel to the ground. Carmasters wheel alignment computer has charts that provide specs for most models, but the main thing is that the measurements should be within one inch from side to side and front to rear if no manufacture specifications available. Riding height is not adjustable except on vehicles with torsion bar type springs. The best way to fix this problem is to replace the springs (Note: springs are recommended to be replaced in matched pairs). Replacing defective or worn shocks and struts can affect ride height even if springs are not replaced. Almost all modern shocks and struts are gas charged and when replacing ones that may have leaked and lost charge, often will increase ride height closer to what it was originally.
Changes in riding height will affect camber and toe so if springs are replaced or torsion bars are adjusted, then the wheel alignment must be checked to avoid the possibility of tire wear. Worn/weak shocks, struts and coil springs can result sag in the riding height, and excess shift during braking that can increase braking distance. If the riding height is good, then normally the springs are good.
Set back is when one front wheel is set further back than the other wheel. With other alignment equipment that measures toe by using only the front instruments, any setback will cause an uncentered steering wheel. Using our good 4-wheel aligner will reference the rear wheels when setting toe in order to eliminate this problem. Our system alignment equipment will also measure set back and give you a reading in inches or millimeters. A set back of less than 1/4 inch is considered normal tolerance by some manufacturers. More than that and there is a good chance that something is bent.
Thrust angle is the direction that the rear wheels are pointing in relation to the centerline of the vehicle. If the thrust angle is not zero, then the vehicle will often "dog track" and the steering wheel may not be centered. The best solution is to first adjust the rear toe to the center line and then adjust the front toe. This is normally done during a 4-wheel alignment as long as the rear toe is adjustable. If the rear is not adjustable, then the front toe must be set to compensate for the thrust angle, allowing the steering to be centered, but if rear could not be centered then even with steering wheel straight vehicle may dog track.
Steering center is simply the fact that the steering wheel is centered when the vehicle is traveling down a straight and level road. A crooked steering wheel is usually the most common complaint that a customer has after a wheel alignment is performed. Assuming that the steering wheel stays in the same position when you let go of the wheel (in other words, the vehicle is not pulling), then the steering center is controlled by the front and rear toe settings. When setting the steering center, the rear toe should be set first bringing the Thrust Angle as close to the vehicle centerline as possible. Be careful not to overlook tires. Even with all steering, suspension and ride height correct, vehicles can still have a pull and not drive straight due to tires. If a tire has a damaged belt, sometimes caused a slipped belt, that will likely cause the vehicle to have a pull and not drive straight. Improper air pressure in tires can not only be dangerous but can also affect steering. Tire sizes not matching left to right or front to rear per manufacture specs can affect steering and in some cases damage differentials and drive trains. Some manufacturers require 1/8” maximum circumference difference so transfer cases and differentials are not damaged. Wrong size tires, different brand, model or type such as touring, all-season, snow, off-road even when the same size on the sidewall are actually significantly different circumference, in some cases even if the same but have significantly different wear. Some AWD manufacturers do not have an allowable size difference, say tires must be the same size, which is why tire often recommended being replaced in sets. Our alignment system computer measures the size of each tire, so if there is too much difference we will know and let our customers know. Our system also checks for bent wheels and will alert if excessive.
Of course, you should always road test the vehicle after every alignment as a quality control check. Another problem with the steering center has to do with the type of roads that are driven on. Most roads are crowned to allow for water drainage, you usually drive on the right side of the crown. This may cause the vehicle to drift to the right so that the steering wheel will appear to be off-center to the left on a straight road.
Primary Angles
The primary angles are the basic angle alignment of the wheels relative to each other and to the vehicle body. These adjustments are the camber, caster, and toe. On some vehicles, not all of these can be adjusted on every wheel.
Setback Front-wheel setback is a measurement taken through the spindles perpendicular to the centerline of the vehicle. Front-wheel setback causes a vehicle to drift to the side with the most setback. A rear-wheel setback is when one of the rear wheels sits further back than the other.
Measurement
A camera unit has a target that is attached to a specially designed clamp which holds on to a wheel. There are usually four camera units in a wheel alignment system (a camera unit for each wheel). The camera units communicate their physical targets wheel positioning with respect to other camera units to a central computer which calculates and displays how much the camber, toe, and caster are misaligned.
Our alignment "tower" contains the cameras as well as arrays of LEDs. This system flashes one array of LEDs for each reflector with a camera centrally located in the LED array "looks for" an image of the reflectors patterned face.
If the camber is different from side to side it can cause a pulling problem. The vehicle will pull to the side with the more positive camber. On many front-wheel-drive vehicles, the camber is not adjustable. If the camber is out on these vehicles, it indicates that something is worn or bent, possibly from an accident and must be repaired or replaced.
If the caster is out of adjustment, it can cause problems in straight-line tracking. If the caster is different from side to side, the vehicle will pull to the side with the less positive caster. 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. If the caster is equal but too positive, the steering will be heavy, and the steering wheel may kick when you hit a bump. Caster has little affect on tire wear. The best way to visualize caster is to picture a shopping cart caster. The pivot of this type of caster, while not at an angle, intersects the ground ahead of the wheel contact patch.
Like camber, on many front-wheel-drive vehicles, the caster is not adjustable. If the caster is out on these vehicles, it indicates that something is worn or bent, possibly from an accident, and must be repaired or replaced.
The toe measurement is the difference in the distance between the front of the tires and the back of the tires. It is measured in fractions of an inch in the US and is usually set close to zero which means that the wheels are parallel with each other. Toe-in means that the fronts of the tires are closer to each other than the rears. Toe-out is just the opposite. An incorrect toe-in will cause rapid tire wear to both tires equally. This type of tire wear is called saw-tooth wear.