collapse called the angle of inclination of the plane of the wheel relative to the vertical. If the wheels are tilted with their upper edges outward, the camber is called positive, and vice versa. Camber is measured in degrees. The correct camber adjustment determines the size and position of the contact patch of the treads with the road surface and allows you to compensate for changes in suspension geometry that occur during cornering and when the car is moving on uneven road surfaces.
Convergence (convergence) called the amount of convergence to each other of the front edges of the wheels of the car. Such a violation of the parallelism of the wheels allows minimizing tread wear by preventing skidding when making turns. At zero convergence, the distance between the front edges of the wheels is equal to the distance between their rear edges. Normal convergence is usually less than a fraction of an inch (1 inch = 2.54 cm). Violation of the adjustment of convergence leads to accelerated wear of the tire tread due to their slippage on the road surface.
coasting called the angle of longitudinal inclination of the king pin / axis of rotation of the wheel, i.e., the angle of deviation of this axis from the vertical in the plane of the wheel disk. If the pivot/kingpin is tilted back, the runout is said to be positive, vice versa.
Note. By analogy, the transverse angle of the axis of rotation of the wheel is the angle of deviation of an imaginary kingpin from the vertical in a plane perpendicular to the DP of the car.
Divergence of steered wheels in a turn called the difference between the angles of rotation of the inner and outer wheels, when the first is turned at a given angle.
Conditions for checking wheel alignment
Checking the installation angles of the car requires a specially equipped overpass / lift. Before starting the test, make sure that the following conditions are met:
- The air pressure in the tires corresponds to the nominal;
- The front wheels are mounted straight;
- The car is not loaded, the fuel tank is full;
- Elements of the car's suspension are upset with force;
- The steering gear is correctly adjusted;
- Backlash in the tie rod ends and suspension ball joints do not go beyond the permissible limits;
- The tread depth of tires mounted on wheels of the same axle is the same.