It is convenient to carry out all work related to technical inspection and replacement of suspension parts on a lift or inspection ditch together with an assistant.
We check the tightness of the fasteners of all parts of the front suspension, tighten the loose connections.
Before checking the backlash in the front suspension with the car at a standstill, we vigorously shake the wheel by the upper part with our hands. In case of strong knocks, check the tightness of the wheel bolts.
If the bolts are well tightened, then hang the wheel and..
... shake it with both hands in a vertical plane. Repeat the test with the brake pedal depressed.
If there is a knock when the brake pedal is depressed (backlash) disappears, then its source is excessive clearances in the hub bearings (see Front wheel bearing clearance adjustment).
The cause of possible knocks may be ball joints. A faulty one can be identified by touch by the play of the ball pin. This hinge is replaceable.
Deformed lower arm axle (it is noticeable even to the eye) replace.
If the wheel alignment angles cannot be adjusted, body deformations are possible, «overwhelmed» rack mudguard, bent spars and cross member. We recommend checking «geometry» body to the service station and, if necessary, replace the cross member.
We check the condition of rubber-metal hinges in the following order:
- we hang out the front wheels of the car and make sure that there is no deformation of the elements (see above);
- the radial displacement of the thrust washer relative to the outer end of the outer bushing of the rubber-metal hinge must not exceed 2.5 mm;
- the distance between the thrust washer and the outer end of the outer bushing of the hinge should be 3-7.5 mm for the lower and 1.5-5 mm for the upper levers.
Rubber-metal hinges must be replaced in case of ruptures and one-sided wear of rubber.
The condition of the lower ball joints is checked in the following order:
- having removed the wheel, we substitute a strong, stable wooden block 280 mm high under the hub and lower the car onto it. For safety, we put the removed wheel under the threshold of the car. We turn out the conical plug from the lower ball joint;
- we measure the distance from the outer part of the hinge cover to the spherical head of the pin with a caliper depth gauge (for clarity, the stabilizer is removed). If this distance is more than 11.8 mm, the hinge is replaced.
We check the condition of the mudguards of the hinges. Hinges with torn covers are replaced as an assembly.
On the new ball joint, turn or deflect the ball pin in different directions. Play, free play of the finger or its strong jamming are unacceptable.
Carefully inspect the suspension springs. Sagging springs, as well as with other damage, are replaced with new ones.
We replace a deformed or worn stabilizer bar. If the suspension rod mounting pads are worn out, we replace them with new ones.
There must be no play in the shock absorber mounts. We are convinced that the rubber-metal hinge in the lower fastening eye has no wear - cracking, delamination, etc., its fastening bolt is tightened. If strong smudges of the working fluid appear on the shock absorber body, we replace it with a new one. It is recommended to replace both shock absorbers at once.
You can check the health of the shock absorbers on a stationary car. We swing the car by pressing several times on the wing in the vertical direction. Having stopped pumping the car, we are convinced that the free vibrations of the body damp out in no more than 2 cycles. There should not be any knocks.