Examination
1. Check tire pressure.
2. Make a test drive. Determine the malfunction as accurately as possible: speed, road surface condition, turns and exits from them on a straight line.
3. Place the machine on stands.
4. Check wheel alignment. In this case, the wheel hubs or brake drums must protrude outside the flange of the disk wheels, or at least be flush with them. Otherwise, replace the rims.
5. Check the wheel suspension, while checking the impeccable condition of the rubber-metal bearings, hinges, shock absorbers and rims.
6. Remove and clean the wheels, while removing the stones from the tread.
7. Check the wheels for brake patches, which can be seen from the thin layer of residual tread, resulting from full braking with locked wheels.
8. Check the tread depth on the tires and compare with each other. With non-brake wear of the tires in front or rear, it is necessary to adjust the wheel alignment. In this case, the adjustment of the convergence must be carried out according to the upper limit of the tolerance.
Attention! To measure the undercarriage, an appropriate measuring system is required, which, as a rule, is only available in workshops.
9. Make a test drive and check again for faults.
Checking the battle in height and side battle of the wheels
1. Install the car on the goats. Install a suitable watch micrometer on the tread, then on the side of the tire. Rotating the wheel slowly by hand, measure the maximum values of the runout in height and lateral runout, mark these places with chalk.
2. Required values: maximum break in height - 0.8 mm; maximum lateral runout - 1.2 mm.
3. If these values are not maintained, balance the wheels on a stationary balancing machine. In this case, the wheels must be centered in the same way as on the machine. Tapered tighteners that center the wheel in a centering hole are not permitted. Permissible residual unbalance, in both balancing planes, is 5 grams.
Elevation runout elimination (alignment)
1. Let the air out of the tire and press down on the rim.
2. Rotate the tire on the rim by 120°.
3. Inflate the tire and check the runout again.
4. If the maximum value is exceeded, turn the tire on the rim an additional 120°and measure the runout.
5. If the maximum value is maintained, balance the wheel.
Rim runout and lateral runout check
1. Install by centering the wheel rim without tire on a balancing machine or machine. Install a clock micrometer.
2. Elevation runout (H) and lateral beat (S) check on the indicated sheets, paying no attention to the unevenness of the rim material and the recess under the valve, which may interfere with an accurate measurement.
Required values: steel rim: H = 0.6 mm; S = 0.5 mm.
3. If the dimensions are exceeded, replace the rim.
Installing wheels on a car
1. With the machine installed on the trestle, set the wheels so that the place of maximum runout in height is at the top. Tighten the wheel bolts in this position crosswise with a torque wrench to 160 Nm.
Attention! If the difference in wear of the individual tires is small, install the wheels with the smallest runout in height and the smallest unbalance weight on the front axle.
2. Make a checkout. If the beating of the front end or the vibration of the steering wheel is again detected, then they are the result of residual imbalance, which is eliminated on the machine by additional balancing.
Wheel balancing on a car
1. When balancing the drive wheels, be sure to install both wheels of one axle on the rollers.
2. The wheels must be driven by the engine so that the wheels rotate synchronously. All-wheel drive machines must be raised on both axles. Balance axles in sequence.
3. Make a control run.
4. If the faults persist, then the radial and lateral movements of one or more wheels are too large. They cannot be measured by means of SRT. In this case, it remains only to replace the front or rear wheels. The tires should only be replaced in pairs.
Visitor comments