Examination
Check tire pressure and correct if necessary.
Carry out a test drive and determine as accurately as possible the conditions for the occurrence of the malfunction: speed range, road surface, cornering or straight ahead.
Raise and support the vehicle.
Check disc alignment. In this case, the wheel hub should protrude above the edges of the disk or be flush with them. If this is not the case, replace the discs.
Check the wheel suspension, for which check the condition of rubber-metal hinges, hinges, shock absorbers and springs.
Remove the wheels and clean them, remembering to remove the stones from the tire pattern.
Check for brake marks on the tires, i.e. places with a shallower depth of pattern, which appear due to braking with locked wheels.
Measure the tread depth of individual tires and compare the results. If the front and/or rear tires show abnormal wear, front and rear toe-in must be measured and adjusted if necessary. In this case, the adjustment of the convergence should provide the upper limit of the permissible values.
Attention: For measurements, it is better to contact the workshop, where there is the necessary equipment.
Take a test drive and check if the problem is still there.
Checking the lateral runout and runout on the height of the wheels
With the vehicle raised, place a dial gauge on the work surface and on the sidewall of the tire. Slowly turn the wheel by hand. Determine the runout on the indicator arrow and mark with chalk the place of maximum runout in height. The maximum runout in height is 0.8 mm, the maximum lateral runout is 1.2 mm.
If these values are not achieved, balance the wheels on a special installation. In this case, the wheels must be centered in the same way as on the car. Conical clamping devices for centering the wheel in the center hole are not allowed. The permissible imbalance in both planes is no more than 5 g.
Elevation runout elimination
Release the air from the tire and press the tabs of the tire into the base of the rim.
Rotate the tire on the rim 120°.
Inflate the wheel and check the runout again.
If the maximum runout value is exceeded, rotate the tire 120°again on the rim and check the runout again. If the desired value is reached, balance the wheel.
Checking lateral runout and runout in disc height
Center a rim without a tire on a wheel balancer or on a vehicle. Install a dial gauge.
Measure the pitch runout (H) and lateral beat (S) on disk. Elevation runout (disk deviation from circumference) is measured on the landing flange of the disk, and the lateral runout is measured on the side surface of the flange of the disk. In this case, you can ignore random jumps in the indicator needle, which are caused by small protrusions or indentations.
Maximum runout in height - 0.3 mm; maximum lateral runout - 0.3 mm.
If the specified values are exceeded, replace the drive.
Installing wheels on a car
With the vehicle raised, set the wheels so that the place with the maximum runout in height is at the top. In this position, tighten the wheel bolts crosswise to 100 Nm.
Attention: If the difference in wear between the individual tires is small, then wheels with minimum height run-out and minimum weight balance weights must be installed.
Take a control trip. If the vibration of the front of the car and the steering wheel is still there, then we can talk about a residual imbalance, which is eliminated by balancing on the car.
Wheel balancing on a car
When balancing the drive wheels, install both wheels of the same axle on a roller stand.
The wheels must be driven by the vehicle's engine so that the wheels rotate synchronously.
Take a control trip.
If there are flaws, then this means that the radial movements or runouts of one or more tires are too large. It is not possible to measure them with workshop equipment. In this case, it remains only to replace the front and / or rear tires. In this case, it is necessary to replace the tires only in pairs.