4.3.16. Check and adjustment of angles of installation of wheels

Check and adjustment of angles of installation of wheels are necessary for ensuring good stability and controllability of the car, and also uniform wear of tires at operation. Check and adjustment of angles of installation of wheels are carried out at special stands according to instructions for their operation.

Adjustment of a corner of disorder and convergence of back wheels a design of the car is not provided. Discrepancy of the valid values measured on the car to the control values provided below can speak wear and deformation of details of a suspension bracket, deformation of a body. At detection of deviations it is necessary to find the cause of deviations in the parameters of a back suspension bracket caused by deformation of its elements and bodies and to eliminate it with replacement of the failed details.

    

PREVENTION Replacement or repair of details of a suspension bracket can cause change of angles of installation of wheels therefore check of angles of installation of wheels is obligatory.

Corner of a longitudinal inclination of an axis of turn of forward wheels:

cars with the hydraulic booster of steering..... 1 °45 '-3 °45’

cars without hydraulic booster of steering..... 0 °30 '-2 °30’

Disorder corner:

forward wheels.....-1 °10 '±20’

back wheels.....-2 °10’ … – 1 °10’

Convergence:

forward wheels..... 0 °10 '±10’

back wheels.....-0 °10 '±40’

Maximum difference of angles of installation of the right and left wheels..... 1 °

Check the angles of installation of wheels on the car without loading with the fuel tank filled half, normal pressure of air in tires and in the absence of excessive side plays in suspension bracket knots.

After installation of the car on the stand, just before check of corners, you "prozhmit" a car suspension bracket, putting two-three times the effort of 392-490 N (40–50 kgfs) directed from top to down, at first to a rear bumper, and then to forward. Wheels of the car have to be located parallel to a longitudinal axis of the car.

During the checking and adjustment of angles of installation of forward wheels at first check a corner of a longitudinal inclination of an axis of turn, then a corner of disorder of wheels and in the last turn a convergence of wheels.

The corner of a longitudinal inclination of an axis of turn of a forward wheel is formed by the vertical and the line passing through the middle of the top support of a telescopic rack and the center of the sphere of the spherical support fixed on the lower lever. Adjustment of a corner of a longitudinal inclination of an axis of turn is not provided by a car design.

The corner of disorder of forward wheels is characterized by a deviation of the average plane of rotation of a wheel from a vertical. Adjustment of a corner of disorder of forward wheels is not provided by a car design.

The convergence of forward wheels represents a corner between the plane of rotation of a wheel and a longitudinal axis of the car. The convergence of forward wheels is regulated change of length of steering drafts.