NANO

WHEELS AND TYRES

475

SUSPENSION

WHEEL RUNOUT

Wheel runout 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 runout:

An "out-of-round" situation where

vibrations are produced as thewheel spindlemoves

up and down.

(b) Lateral runout:

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. Remove wheel covers or wheel caps.

2. 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.

3. Position a dial indicator on a rigid fixture.

4. For lateral run out check, position the indicator

point horizontally against the side of the wheel

rim flange. For a radial runout check position the

indicator point vertically against the tyre mounting

surface of the wheel rim flange.

5. Slowly rotate the wheel one full revolution while

observing the dial indicator.

6. Rotate the wheel to the position where the lowest

dial indicator reading was obtained.

7. Zero out the dial indicator.

8. Slowly rotate the wheel one full revolution while

observing the dial indicator.

9. Record the highest dial indicator reading. Disregard

any indicator readings caused by welds, paint runs,

scratches etc.

10. Perform lateral and radial run out checks on both

inboard and outboard sides of the wheel.

11. Compare each reading with the specified values

(as given below) If the run out is greater than the

specification, the wheel must be replaced.

Run Out Checking Locations

Radial run Lateral run

out limit

Steel wheel / 1.14 mm 1.4 mm

Alloy wheel