- Self-resetting of the wheels when the car exits the turn and maintaining the direction of movement when the steering wheel is released and driving on a flat road without inclination and side wind (this is achieved by the presence of the so-called stabilizing moment).
- The smallest losses on the rolling of the wheels and their friction on the road.
A complete wheel alignment check should include measurements of the toe and camber angles of the rear wheels. Adjusting all 4 wheels of the car ensures that all 4 wheels roll in exactly the same direction. If the car's wheel suspensions are geometrically adjusted, then fuel economy and tire durability will be maximized, and handling will be the most efficient and safe.
Wheel alignment
Wheel alignment - pre-installation (with a stationary vehicle) wheels located on the same axle, in which the distance between their front edges is less than between the rear. This position of the wheels is necessary to compensate for the elasticity of the wheel suspension units, as well as to compensate for the wear of these units.
With a correctly installed toe-in, the wheels are in the longitudinal plane during movement, that is, parallel to the direction of movement.
Incorrect toe or toe angle causes tire wear and increases fuel consumption. Always adjust the toe angle at the end.
Longitudinal inclination of the axis of rotation of the wheel
Longitudinal inclination of the axis of rotation of the wheel - deviation from the vertical in the longitudinal plane of the axis around which the wheel turns. Tilt back is positive and tilt forward is negative. The longitudinal inclination of the axis of rotation of the wheel affects the occurrence of a stabilizing force, which tends to set the steered wheels in the direction of travel «directly».
Weak springs or overloading the vehicle affect caster. The higher the angle of longitudinal inclination of the axis of rotation of the wheel, the greater the force that prevents the wheel from turning. The caster angle of the wheel axis is measured in degrees and is not adjustable. The optimal value of this angle allows you to achieve a small effort when turning the wheels and, at the same time, to ensure the stabilization of the direction of the car on the road.
Camber
Camber - the slope of the longitudinal plane of symmetry of the tire. The outward slope is considered positive, the inward slope is considered negative. The camber angle is measured in degrees. Camber affects both directional control and tire wear.
If the car has too much positive camber, the edges of the tire on the outside of the car will wear out. If the car has too much negative camber, the edges of the tire on the inside will wear out. Camber is an unregulated parameter.
Lateral inclination of an axis of turn of a wheel
Transverse inclination of the axis of rotation of the wheel - the tilt of the steering knuckle from the vertical in its upper part. Measure the lateral inclination of the wheel axis between the vertical line and the line passing through the center of the strut and the lower ball joint as viewed from the front of the vehicle.
The transverse inclination of the axis of rotation of the wheel is necessary for the formation of the correct shoulder (radius) running-in (see below).
The transverse inclination of the axis of rotation of the wheel on vehicles with front-wheel drive must be such that the shoulder (rolling radius) was negative.
Corner "kingpin-wheel"
This is the angle formed by the axis of rotation of the wheel and the longitudinal plane of symmetry of the tire.
Corner "kingpin-wheel" measured in degrees. In most cases, this angle is not directly measured. To determine it, subtract the negative or add the positive camber angle to the lateral inclination of the wheel axis.
Shoulder (radius) running-in
The break-in radius is the distance, measured along the road surface, between the vertical plane of symmetry of the tire and the point at which an imaginary line, which is a continuation of the wheel's axis of rotation, intersects with the road surface. If the points of intersection of the imaginary axes of rotation of the wheels with the road surface are inside the track (tire symmetry limited by vertical planes), then the running-in shoulder is considered positive. In this case, the rolling resistance force of the wheel forms a moment tending to turn the steered wheel outward.
If the points of intersection of the imaginary axes of rotation of the wheels with the road surface go beyond the symmetry planes of the wheels to the outside, then the running-in shoulder is considered negative. In this case, the wheel resisting rolling tends to turn inside the track.
The use of a negative break-in arm increases the stability of a front-wheel drive vehicle during acceleration and braking.
Leverage (radius) running-in is determined by the design of the car and is an unregulated value.
Wheel offset
Wheel offset is the distance that one front hub/bearing assembly can be behind another front hub/bearing assembly. Wheel shift is usually caused by the vehicle colliding with an obstacle.
Wheel angle
Steering Angle - The angle at which each front wheel is rotated to the vertical as the vehicle turns.
Loosen the locknuts of the threaded connection of the steering rods with the tips of the steering rods.
Turn the right and left tie rod adjuster to the toe value from 0°-10°to 0°+10. In this adjustment, the left and right tie rods must be the same length.
Puff. Tighten the tie rod bolts to 64 Nm.
Wheel alignment values
Checking the camber and caster angles of the front wheels
The camber and caster angles of the front wheels are not adjustable. Refer to table "Wheel adjustment" this section. Before measuring the camber angle or caster angle, raise and lower the vehicle three times by the bumper to avoid false readings. If the measured values for the camber or caster angle of the front wheels are out of specification, locate and replace or repair any damaged, loose, bent, dented or worn suspension parts. If the cause is the body of the car, then repair the body.
Checking the camber angle of the rear wheels
The camber angle of the rear wheels is not adjustable. Refer to table "Wheel adjustment" this section. If the rear camber angle deviates from the specifications, determine the cause and correct it. If damaged, loose, bent, dented, or worn suspension parts are found, these parts must be repaired or replaced. If the cause is the body of the car, the body needs to be repaired.
Checking the convergence of the rear wheels
The convergence of the rear wheels is unregulated. Refer to table "Wheel adjustment" this section. If rear wheel toe angle deviates from specifications, check rear axle housing and steering knuckle for possible damage on vehicles without anti-lock brake system (ABS), and on vehicles with anti-lock braking system - rear axle housing and hub with bearing.