The angles of installation of wheels considerably influence stability of the car, wear of tires and fuel consumption. Distinguish the following angles of installation of wheels.

Fig. 10.14. Disorder of a forward wheel

Disorder is an inclination of wheels in the vertical plane of rather average line of the car ( fig. 10.14 ). It can be positive if wheels are inclined outside, and negative — if wheels are inclined inside. The disorder corner generally influences uniformity of wear of tires of forward wheels. If the difference of corners of disorder of wheels of the forward bridge more than 30’, then takes away the car aside at the movement on a straight line. Adjustment of disorder can be made only in a junction of a rotary fist with the lower part of a depreciation rack.

Fig. 10.15. Convergence of forward wheels

Convergence — a difference of the distances between wheels measured at height of their axes between edges ободьев ( fig. 10.15 ). The positive convergence means that wheels are in front located more closely to each other, than behind at measurement at height of an average point of a wheel. The negative convergence means that ahead of a wheel are at bigger distance from each other, than behind. On VW Passat the neutral convergence is established. At cars with the amplifier of steering the convergence is regulated only by the right steering draft.

The cross inclination of an axis of turn of a wheel is a corner between the axis of an inclination of a rotary fist and a vertical which is carried out through a point of fastening of a wheel in the longitudinal direction of the car. At positive value of a corner self-return of a wheel to average situation after turn improves.

Fig. 10.16. Corner of a longitudinal inclination of an axis of turn

Corner of a longitudinal inclination of an axis of turn ( fig. 10.16 ). The axis concerning which there is a turn of a wheel is placed in space so that its lower part is inclined forward. Such corner of a longitudinal inclination is called positive.

Existence of a longitudinal inclination leads to creation of the stabilizing moments seeking to return the operated wheels to provision of the rectilinear movement.

Conditions of check of angles of installation of wheels

Pressure in tires has to meet standard.

The car has to be installed on the flat horizontal platform.

The car should not be loaded and has to have the fuel tank filled half.

Before check of angles of installation of wheels shake a car body.

Steering has to be serviceable and correctly adjusted.

In drafts of steering there has to be no side play.

There has to be no side play in a suspension bracket of wheels.