TIGOR EV

WHEELS AND TYRES 16 IV. WHEEL RUN OUT Wheel run - out is because of poor bead seating on the rim. Poor bead seating is usually the result of improper mounting or the use of improperly made wheels. Basically there are two types of run-out: a. Radial run-out: An "out-of-round" situation where vibrations are produced as the wheel spindle moves up and down. b. Lateral run-out: A side-to-side or wobbling movement of the tyre and wheel. Procedure to perform a wheel lateral and radial run out check is as given below: 1. Mount the wheel on the vehicle or wheel balancer. If on the vehicle, properly lift and support the vehicle such that wheels can turn freely. 2. Position a dial indicator on a rigid fixture. 3. For lateral run out check, position the indicator point horizontally against the side of the wheel rim flange. For a radial run out check position the indicator point vertically against the tyre mounting surface of the wheel rim flange. 4. Slowly rotate the wheel one full revolution while observing the dial indicator. 5. Rotate the wheel to the position where the lowest dial indicator reading was obtained. 6. Zero out the dial indicator. 7. Slowly rotate the wheel one full revolution while observing the dial indicator. 8. Record the highest dial indicator reading. Disregard any indicator readings caused by welds, paint runs, scratches etc. 9. Perform lateral and radial run out checks on both inboard and outboard sides of the wheel. 10.Compare each reading with the specified values (as given below) If the run out is greater than the specification, the wheel must be replaced. Steel wheel / Alloy wheel Radial run-out limit Lateral run- out limit 1.14 mm (0.045 in) 1.4mm (0.055 in.) V. DO'S AND DON’TS  For each vehicle, tyre of a particular size, pattern and ply rating is recommended for usage. Fit only recommended tyres.  The rim and wheel used must also be of the recommended type and in a very good condition.  Care must be taken while mounting the tyre on the rim. Improper tools and careless handling will not only damage the tyre but could result in accidents causing serious injury.  It is recommended that with each new tyre, an appropriate new tube and where applicable, a new flap should be used.  The tyre has to be ensure with the right inflation as recommended by the manufacturer. Under-inflation and over- inflation can seriously reduce the life of the tyre and may even cause accidents due to premature failures. The inflation pressure should be checked at least once in a week when the tyres are cold and have not run for long.  The maximum load imposed on a tyre should never exceed the maximum load carrying capacity of the tyre.  Tyres rotation should be carried out as recommended in the service schedule.  Driving on worn out tyres can be very dangerous and can lead to serious accidents.