911 Turbo AWD F6-3600cc 3.6L SOHC Twin Turbo (1997)
4a. Fine balancing of the front wheels to correct torsional vibrations of the steering wheel at approx. 120 km/h
4b. Fine balancing of the rear wheels to correct vibration at 180 km/h and speeds greater than 230 km/h.
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The following applies to both the front axle and rear axle:
The measured-value pickups must always stand on a firm surface.
The measuring stand support must be located as close to the wheel as possible.
Doors and lids must be closed and the vehicle must not be touched during the measuring operation.
Ensure that the lifting equipment used (jack, platform lift) does not touch the vehicle.
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Affix balancing weights on the outer plane (uniform procedure/could also be distributed or affixed on the inner plane).
Under no circumstance remove the weights affixed during stationary balancing.
Mark the balancing weight required by electronic fine balancing using a prick punch in order to distinguish it.
Step4a: (Fine Balancing Of The Front Wheels)
NOTE: On vehicles with all wheel drive, all four wheels must be raised and must be able to turn freely.
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Position measuring support or both measuring supports.
Ensure that the take-up fork of the measuring support does not damage any parts.
Before the first measuring run, re-check to ensure that slipping from the measuring support is not possible.
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Centre the sensitivity control. Perform measuring run.
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Affix balancing weight if necessary.
Then perform a check run.
If the result is unacceptable (precondition: the work was performed properly), calibrate the finish balancer.
This means that the sensitivity control must be adapted to the actual situation.
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If the balancing result is still not quite right even after calibration (for example, 5 g), change the balancing weight according to the balance
correction table (balance correction schematic) and thereby eliminate the residual imbalance.
Step 4b: (Fine Balancing Of The Rear Wheels)
NOTE: On vehicles with all-wheel drive, all four wheels must be raised and must be able to turn freely.
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Place measuring support on the right and left.
Balance the driven axle only if both wheels are jacked up at the same time.
Ensure that the take-up fork of the measuring support does not damage any parts.
Before the first measuring run, re-check to ensure that slipping from the measuring support is not possible.
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Set the sensitivity control to 3 ............................................................................................................. 3.5 (depending on the equipment version).
This corresponds to approx. 1/3 of the max. sensitivity.
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Perform measuring run at a speed of 130 km/h or 1,150 to 1,200 rpm (wheel revolutions) in the highest gear or in the upper transmission range.
Affix the corresponding balancing weight.
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Perform a check run.
Calibrate the finish balancer if the balancing result is unsatisfactory.
This means that the sensitivity control must be adapted to the actual conditions.
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Then (in the case of a good balancing result) slowly increase the speed to 190 km/h and carefully observe at what speed obvious vibration can
be felt at the steering wheel and/or seat again (mainly at 175±5 km/h).
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Maintain this speed and re-balance the wheels in the same way as at 130 km/h.
Do not affix any new weights; instead, improve the wheels by changing the existing weights according to the "balance correction"
schematic.
IMPORTANT: The imbalance values listed here in this speed range are not "real" values. They are actually max. 1/4 to 1/3 of the indicated
values.
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The subjective impression in the vehicle is the decisive criterion here.
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The balancing process is complete only when no more vibrations caused by imbalance are perceptible.
Removing Air Valve of Technology Wheel
General
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It is not necessary to replace the steel valve each time the tire is changed as the seal rings of the valve are highly resilient (silicone).
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However, the valve should be replaced at every second tire change or after three years at the latest.
