Warning. Checking the wheel alignment is mandatory if you are replacing or repairing suspension parts that may result in a change in wheel alignment.
Carry out the control and adjustment of the wheel alignment angles on the vehicle with a design load of 2205 N (225 kgf) (three people 75 kg).
When monitoring and adjusting the angles of installation of the front wheels, it is necessary to be guided by the parameters indicated in Table. 4-1.
Table 4-1. The parameters of the angles of installation of the front wheels of the car
Note. For the period of stabilization of the elastic elements until the first maintenance (mileage 2000...3000 km) the values given in parentheses are allowed.
Before setting wheel alignment check:
- the total play in the steering should not exceed 10°.
- axial play in the bearings of the front wheel hubs should not be more than 0.15 mm;
- the gap in the upper ball pin should not be more than 0.7 mm;
- dents and deformations of wheel rims, deformations and cracks of levers, extensions and hinges of the front and rear suspensions are not allowed (visual inspection);
- tire pressure.
Eliminate any faults found and make the necessary adjustments.
After installing the car on the stand, immediately before checking the corners, it is necessary «to live» suspension of the car 2-3 times for self-alignment of the front suspension units, applying a vertical load of 400 to 500 N by hand (from 40 to 50 kgf) first to the rear, then to the front bumpers.
The sequence of checking and adjusting the wheels should be as follows:
1. The angle of the longitudinal inclination of the axis of rotation of the wheels.
2. Camber angle.
3. Toe-in.
The angle of the longitudinal inclination of the axis of rotation. To adjust the pitch angle of the steering axis:
- the number of shims on the bolts of the upper arm axle is changed;
- Refer to Table 4-1 and calculate the number of shims required to remove or install using Table 4-2.
Table 4-2
- open the hood of the car;
- unscrew the nuts securing the axle of the upper arm of the front suspension until the shims are freely removed;
- remove or install the calculated number of shims on each upper arm axle mounting bolt;
- tighten the nuts securing the upper arm axle with a torque wrench, the tightening torque of the nuts is from 70 to 80 Nm (from 7.0 to 8.0 kgf·m);
- repeat the above operations for the other front wheel.
Camber angle of the front wheels. If the camber angle differs from the norm, then it is necessary to adjust it by changing the number of washers 21 (see fig. 4-1), installed between the upper arm axle and the cross member bracket.
To reduce the camber angle, remove the same number of washers from both bolts, and to increase, add.
The convergence of the front wheels. If the toe-in value differs from the norm, then it is necessary to loosen the nuts of the coupling collars of the steering rods and turn the steering linkage rod by the same amount in opposite directions with a key; in this way, the couplings are screwed on or rolled up and change the length of the steering rods. After adjusting the lengths of the steering rods, the steering wheel should be in a position corresponding to a straight-line movement.
After adjusting, install the tie-down collars with a slot towards the rear of the car, with a permissible deviation up or down no more than 60°from the horizontal plane of the car and tighten them in this position. When the nuts are tightened, the edges of the slots of the tie-down collars must not touch.
After adjusting the toe-in, check whether the wheels and steering gear parts are touching the adjacent parts of the wheel suspension and bodywork. To do this, turn the wheels in both directions until the bipod stops against the bolts of the steering gear housing.