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9.9. WHEELS AND TIRES CARE
In the process of vehicle operation it is necessary to timely tighten the loose
wheel nuts to avoid damaging the fastening holes, remove rust from the wheels
and restore their colour.
To ensure maximum service life of the tires the following rules should be
observed:
— maintain the required air inflation pressure in the tires. Pressure should
be checked when the tires are cold before starting out. When stopping during
a trip carry out visual inspection of the tires and inflation pressure in them.
Never drive the vehicle with the underinflated tires even for a short distance.
Pressure should not be reduced in warm tires because during the vehicle move
ment pressure increase is inevitable due to heating of air inside them;
— check and balance the wheels with tires on a special stand at the service
station. The allowable residual unbalance from each side of the wheel with tire
should not exceed 100 g on the wheel rim;
— on returning from a trip and when at halt inspect the tires and remove
the foreign objects. The vehicle should be parked on clean and dry place. Avoid
oil, gasoline, oil paint getting on the tires;
— prevent vehicle standing with underinflated tires;
— rotate the tires (Fig. 9.9), if necessary to get even wear of all tires, spare
one including, as well as to provide proper selection of the tires for each axle.
The tires on an axle should be of the same tread wear and more reliable tires
should be installed on the front axle of the vehicle.
Fig. 9.9.
Tire Rotation
Diagram
Maximum permissible rate of tread wear corresponds to residual depth of
the tread grooves equal to 1.6 mm which is determined by measurement or by
tread wear indicators. These indicators of 1.6 mm high will appear as wide bands
incorporated in the tread pattern and marked on the tire sidewalls by TWI
marks.
