4.1.1. Wheels and tires

Angles of installation of forward wheels
When checking angles of installation of forward wheels by means of special adaptation (wheel alignment tester) always install the car on a plain horizontal surface so that forward wheels were in provision of the rectilinear movement. Before check be convinced that a forward suspension bracket, steering and wheels are in normal technical condition, and pressure in tires meets standard.

Convergence of wheels

Fig. 4.1. Convergence of wheels


The convergence of wheels (a difference of the sizes B – And or the sum of corners and + b) is regulated by rotation of tips of steering drafts (fig. 4.1).
For change of a convergence of wheels rotate tips of the right and left steering drafts on identical corners in opposite directions. The size of a convergence will decrease at rotation of a tip of the left steering thirst in the direction for a back part of the car (and a tip of the right steering draft – in the direction to a forward part of the car).
Convergence V-and: nominal rate – 0±2 mm.

Fig. 4.2. Adjustment of a convergence of wheels



NOTE
Adjustment of a convergence of wheels is made by turn of tips left and the right steering drafts on identical corners (fig. 4.2).

At adjustment of a convergence of wheels weaken collars of protective covers of steering drafts for prevention of twisting of covers.
After adjustment reliably tighten lock-nuts of tips of steering drafts and reliably establish collars of protective covers.
Execute adjustment of a convergence of wheels so that the result corresponded to range + 1 mm.
Moment of an inhaling of a lock-nut of a tip of steering draft: 50–55 N · m.

Disorder of wheels
Disorder of forward wheels is provided with geometry of a forward suspension bracket (mutual position of a rotary fist and a forward rack of a suspension bracket) i.e. is adjusted at manufacturer and is not subject to adjustment in use.
Disorder of wheels: 0 ° + 301.

Longitudinal inclination of an axis of turn

Fig. 4.3. Longitudinal inclination of an axis of turn


The longitudinal inclination of an axis of turn is adjusted at manufacturer and is not subject to adjustment in use (fig. 4.3).
If the longitudinal inclination of an axis of turn does not correspond to nominal rate, replace the deformed or damaged suspension bracket details.
Longitudinal inclination of an axis of turn: 2 °49 '+30'.

NOTE
The worn-out or damaged details of a forward suspension bracket have to be replaced before check of angles of installation of wheels.


Fig. 4.4. The special tool for measurements of angles of installation of wheels


Special adaptation (09529-21000) (fig. 4.4) is used to measurements of angles of installation of wheels.
The longitudinal inclination of an axis of turn and disorder of wheels are adjusted at manufacturer and are not subject to adjustment in use.
If the longitudinal inclination of an axis of turn and disorder of wheels do not correspond to nominal rate, then replace the deformed or damaged suspension bracket details.
The difference in the angles of installation (a longitudinal inclination of an axis of turn and disorder of wheels) between the right and left wheel has to be within 0 ° ±30’.

Angles of installation of back wheels

Fig. 4.5. Tip of the left cross lever


Rotation of a tip of the left cross lever clockwise increases a convergence of wheels (fig. 4.5).
Rotation of a tip of the right cross lever clockwise reduces a convergence of wheels (see fig. 4.5).
Nominal rate: 3–7 mm.

NOTE
Adjustment of a convergence of back wheels is made by change of length (turn of tips) of cross levers of a suspension bracket.

Wear of tires

Fig. 4.6. Height of the drawing of a protector of tires


Measure height of the drawing of a protector of tires (fig. 4.6).
Height of the drawing of a protector of tires (minimum admissible value): 1,6 mm.
If height of the drawing of a protector is less than minimum admissible value, replace the tire.

NOTE
At achievement of minimum admissible height of a protector on the tire wear indicator strips appear.

Measurement of a beating of wheels
You will hang out wheels of one of axes of the car and establish safety racks under the car.

Fig. 4.7. Points of measurement of a beating of a wheel


Measure a wheel beating by means of the indicator of hour type, as shown in the figure 4.7.
Replace a wheel if its beating exceeds maximum permissible value.
Wheel beating (maximum permissible value of a radial beating of a steel disk): 0,6 mm.
Aluminum disk:
Axial..... 1,0 mm
Radial...... 0,3 mm
Axial...... 0,3 mm

Inhaling of nuts of fastening of a wheel
The moment of an inhaling of nuts of fastening of a wheel for a wheel with a steel disk and wheels with an aluminum disk identical.
Inhaling moment: 90–110 N · m.

Fig. 4.8. Inhaling of nuts of fastening of a wheel



ATTENTION
After an inhaling of nuts by means of a pneumatic tool (a shock gaykovert) check the final moment of an inhaling a dynamometer key (fig. 4.8).


Fig. 4.9. Order of an inhaling of nuts of fastening of a wheel


Order of an inhaling of nuts of fastening of a wheel (fig. 4.9).
Check the moment of an inhaling of nuts of fastening of a wheel after their tightening the nominal moment in the diagonal sequence.

Shift of wheels

Fig. 4.10. Scheme of shift of wheels


At shift of wheels use the scheme provided on the figure 4.10.

Check of course stability
If at the movement the car takes away aside, then trade wheels places according to the procedure given below.

Fig. 4.11. Reinstallation of wheels when checking course stability of the car


Trade places forward right and forward left wheels, then execute dorzhny tests for check of course stability of the car (fig. 4.11).

Fig. 4.12. The scheme of reinstallation at withdrawal of the car to the opposite side


If the car takes away to the opposite side, then trade places forward and back wheels, then again execute dorzhny tests (fig. 4.12).

Fig. 4.13. The scheme of secondary reinstallation at withdrawal of the car aside


If the car takes away aside, then again trade places forward right and forward left wheels, then execute dorzhny tests (fig. 4.13).

Fig. 4.14. Replacement of wheels


If the car takes away to the opposite side, then replace forward wheels with new (fig. 4.14).