If the camber angle isn't sufficiently negative, this tire will lean too far, causing the inside of the tread to lift and placing excess stress and load only on the outside of the tread and outer shoulder. This does not mean that street vehicles should have tons of negative camber, since normal street driving will result in excess wear on the inside tire shoulder and tread area. Camber angle always must be adjusted to maximize the tread contact patch based on the driving requirements.
In most cases, OE specifications will call for a slightly positive or zero camber angle in order to maximize tire wear and traction, and to provide easier steering and greater resistance to directional "darting" in a straight line. Unless you're tuning a suspension for a specific race track that demands a unique individual wheel camber setting, generally the camber angle will be close to identical side-to-side.
If camber angles differ appreciably, the car will pull in straight lines and under braking, always pulling toward the side with less negative camber. For instance, if the left front wheel has three degrees negative camber but the right front wheel has one degree negative camber, the car will pull to the right. Front suspension camber angles are adjustable, but the level of difficulty varies depending on suspension design.
If more negative camber is required, the upper arm can be moved further inboard, or the lower arm can be moved further outboard. Conversely, if more positive camber angle is needed, the upper arm can be moved outboard, or the lower arm can be moved inboard. If the OE setup does not allow adjustment, aftermarket adjusters are readily available for either top-strut or bottom-strut applications.
Rear camber may or may not be adjustable, depending on the type of rear suspension. If a live axle is present a rigid, one-piece axle housing on a rear-drive vehicle , camber likely won't be adjustable. However, if an independent rear axle is featured, camber should be adjustable either via eccentric bushings at the inboard control arm pivot points, or by means of an eccentric at the strut-to-rear upright. If adjustment is available either through OE design or with the use of aftermarket adjusters , it's best to adhere to OE specifications for street driving.
The only need to vary this is if the vehicle is being set up for competition use, in which case the same rules apply that are required up front -- to obtain the maximum tread contact patch based on track requirements. Camber angle directly affects tire wear, since the camber angle may contribute to excessive inner or outer tread wear if not adjusted properly.
Caster angle involves only the front, or steering end, of the chassis. The caster angle, or steering axis angle, involves the relationship of the upper ball joint or top of the strut mount to the lower ball joint as viewed from the side of the vehicle. All vehicles should feature a "positive" caster angle, where the upper suspension pivot point is located behind the lower pivot point again, as compared to a true vertical.
If the caster angle is zero where the lower pivot is directly below the upper pivot , directional control will suffer, and there would be little, if any, steering wheel return.
If the caster angle is negative where the upper pivot point is located ahead of the lower pivot , the vehicle will be virtually undriveable due to extremely poor directional control. Like camber, the caster angle is measured in degrees.
The caster angle is a major contributor to directional control. A too-small not positive enough caster angle may make the vehicle too twitchy but would require less driver input to turn the wheel , especially as speed increases. Theoretically, the greater the caster angle, the more directional control you'll have at higher speeds which also requires slightly more driver input at the steering wheel.
However, all suspension systems are designed to perform best at a specific caster angle, so always follow the OE specification in order to achieve the correct balance between turning effort and vehicle stability control. Front caster angle may or may not be readily adjustable, depending on suspension design. If the front suspension features upper and lower control arms, the upper arm likely will be adjustable, either via the addition or removal of shims between the upper arm and frame or via eccentric bushings.
To alter camber, the adjustment must be performed equally at front and rear attachment points in order to move the upper arm pivot inboard or outboard.
If the vehicle features MacPherson-type struts, the top of the strut can be moved forward or rearward to alter the caster angle since the top strut mount serves as the upper locating point. On most strut-equipped vehicle, no OE caster adjustment is readily offered. While the caster angle itself is not a direct tire-wear angle, improper caster angle can contribute to excessive tire wear in conjunction with improper camber and toe angles. Because of the travel arc that occurs when the wheels are turned due in part to the caster angle and steering axis inclination , individual wheel toe angles will change compared to their straight-ahead static settings.
For example, when the steering wheel is turned to the left, the left front wheel will exhibit greater toe-out as compared to the number of degrees that the right front wheel toes-in. This phenomenon, designed into the suspension system, decreases the turning radius of the vehicle and helps to prevent tire scrubbing during turns. Steering axis inclination, also called SAI, represents a predetermined and non-adjustable angle between a true vertical drawn through the center of the tire and a line drawn through the upper and lower ball joints when viewed from the front of the vehicle.
If too much toe-out is present, the feathering will angle toward the outside of the vehicle. What causes bad toe alignment? Toe is the most common cause of tire wear with wheel alignment. Excess toe-in will increase wear to the outside of the tire.
When the front of the tires are further apart than the rear, the wheels are toed out. Excess toe-out wears the inside of the tires. What is the difference between toe in and toe out? Toe is the side-to-side difference in distance between the front and rear of the front tires. If the distance is closer at the front, it's called toe-in.
If the difference is closer at the rear, it's called toe-out. Does toe affect camber? Front toe is 'set' by the tie rods, but altering camber changes the relation of the spindle to said tie rods, affecting toe measurements. That's why camber is always set before toe. And the answer to the original question is no, toe will not impact camber.
How do you check camber alignment? To check camber, make sure the vehicle is parked on level ground. If not, factor the ground slope into the camber reading. Then place a straight edge across the wheel use the inner lip if the outer is nicked or uneven and use an angle finder to reveal camber.
How do you use a toe plate? When using toe plates be sure to have the toe plates resting flat on the ground and centered on the tire. Is this measurement taken from the front surface of the tread to the back surface or some other point? I measured across the vehicle from edge of tire to edge of tire and then compared the difference from the front to the back.
I know this is not correct but need to know how to set it correctly. Your help is appreciated. If you have a center rib that is true and concentrc you can measure from there.
Be sure to spin the tire to check. If not use the block method. They make or made a spring loaded tool to do this. Once both tires are marked, measure the rear as high as you can, and then the front at the same height. Then adjust the tierod as needed. Be sure to bounce the front before and after to make sure the thing is not loading the tierod ends.
Another suggestion is to get a couple of sheets of finised cardboard under each tire. Most driveways do not qualify. Got another idea, How about using a spare set of rims, that have no tires on them.
Place them on the front of the vehicle, with it jacked up.
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