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Vehicle pulls to one side > < Checking radial and lateral run-out on rim

A1

Match mounting
Match mounting
When radial or lateral run-out of the wheel and tyre coincide, the out-of-true running of the wheel is amplified by the tyre.
For technical reasons, 100% true running is not possible when there is radial and lateral run-out on the wheel and tyre.
Under unfavourable circumstances, the radial or lateral run-out of the entire wheel with tyre may be greater than permitted.
The individual values of the wheel and the tyre may nevertheless each be within the permitted tolerances.
Turning the tyre strategically with respect to the wheel can partially compensate for radial or lateral run-out.
This procedure, known as "match mounting", can be used to optimise the true-running properties of the wheel and tyre assembly.
Before match mounting the used wheels which are fitted on the vehicle, the tyres must be run warm. This will eliminate any flat spots caused by storage or handling.
Procedure for match mounting:
  Note
t  On rims with bonded wheel trims, take care not to scratch the wheel trims.
t  Wheel trims have a very sensitive surface.
t  If a wheel trim is damaged, the rim must be renewed.
   
t  The wheel trim cannot be renewed.
–  Deflate the tyre.
–  Press the tyre beads off the rim flanges.
–  Coat the tyre bead all round with tyre fitting lubricant.
–  Rotate the tyre 180° with respect to the wheel.
–  Inflate the tyre to approx. 4 bar.
–  Clamp wheel with tyre on balancer.
–  Check true running/radial and lateral run-out.
  Note
t  If the specified value for radial and lateral run-out is not exceeded, the wheel can be balanced to 0 grams. For specified values, refer to page → Anchor.
t  If the radial and lateral run-out are not within the specified values, the tyre must be rotated again.
–  Deflate the tyre and press off the tyre beads from the rim flanges.
–  Rotate the tyre 90° with respect to the wheel (1/4 of a turn).
–  Inflate the tyre to 4 bar again and check true running.
  Note
t  If the specified value for radial and lateral run-out is not exceeded, the wheel can be balanced to 0 grams.
t  If the radial and lateral run-out are not within the specified values, the tyre must be rotated again.
–  Press the tyre off the rim flanges again as described above.
–  Rotate the tyre 180° with respect to the wheel (1/2 a turn).
If the radial and/or lateral run-out are still not within the specified values, check the rim for radial and/or lateral run-out.
If the measured values for radial and lateral run-out of the wheel are within the specified values, the tyre has an impermissibly high radial or lateral run-out. In this case, the tyre must be renewed.
  A44-10265

Vehicle pulls to one side > < Checking radial and lateral run-out on rim