Balancing/optimizing wheels

In certain cases, it may be necessary to measure radial force variations. This should be done before normal balancing is performed.

The entire process is subdivided into several operation:

1. Fitting the tyre on the rim.
2. 1. Measuring radial force variations and optimizing the wheels if necessary. Then balancing the wheels.
   2. As an alternative to item 2 A, if there is no device available to measure radial force variations: Stationary balancing of the wheel (eliminating static and dynamic imbalance) with optimisation of rolling smoothness.
3. Fitting the wheel on the vehicle.

Further to 1: Fitting the tyre on the rim 

• Remove rubber residues and dried-on tyre paste from the rim, especially from the rim bead and the hump.
• Check rim for damage; remove old balancing weights.
• Use the specified tyre mounting pastes Remaxx Sport mounting paste (from Rema Tip Top/Item No. 593 0577) or Bead Lubricant (from Rema Tip Top/Item No. 514 4985) or Gleitmittel VA sliding compound (from Azett/Item No. 5000-021-220) so that the tyre does not turn on the rim - undoing all your careful work - the first time you drive the vehicle. If the tyre turns by as little as 20 mm with respect to the rim, this can worsen an optimum balancing result.
• Fit tyre on the rim. When doing so, it is a good idea - and even necessary in some cases - to fit the tyre at a favorable position with respect to the rim (matching). Compare Controlled and Uncontrolled matching below.

→ Use a tyre filling cage.

Tyre filling cage 

• Fill the tyre to a maximum pressure of 4.0 bar. By the time the pressure reaches 4.0 bar, at the latest, the tyre beads must pop out of the deep bed and over the hump of the rim bead in order to avoid fractures of the bead core. If necessary, interrupt the process and generously coat all necessary surfaces with sliding compound (tyre mounting paste). Then repeat the process.
• Uncontrolled matching: Turn the tyre on the wheel by 90° or 180° if necessary in order to achieve an acceptable value with regard to rolling smoothness (true running, imbalance and distribution of balance weights).
• Controlled matching: With a balancing machine with matching program. In most cases, this produces an even better result with regard to the rolling smoothness (true running, imbalance and distribution of the balance weights) than can be achieved with uncontrolled matching.
• Check the fit of the tyre on the rim using the bead centering line.
• Set the prescribed tyre pressure.

Further to 2A: Measuring radial force variations 

• Tension wheel on balancing machine with radial force variation measurement (vibration monitoring system).
• Observe the operating instructions of the balancing machine (adjust the machine from time to time).
• The contact surface of the wheel on the balancing flange (flat surface) and the centering surface must be clean.
• The display disabling function must be switched off.
• Adjust tyre pressure to 2.7 bar (best test pressure) when balancing and measuring radial force variations.
• Particular attention must be paid to the wheel mounting when measuring radial force variations and when balancing. Using the special pressure pieces provided by the manufacturer of the balancing machine will ensure that wheels are balanced accurately and there is the highest possible repeat accuracy. Read the operating instructions.

Maximum deviations permitted in radial force variation result:

Radial force variation (peak-to-peak vibrations)	170 N
Radial force variation 1st Harmonic (variation)	109 N

If these values are exceeded, the tyre must be matched on the rim.

If these values are not reached, the wheel must be balanced.

Further to 2B: Stationary balancing with optimisation of rolling smoothness 

• Clamp wheel on stationary balancing machine.
• Read the operating instructions for the balancing machine; adjust the machine from time to time, if necessary.
• The contact surface of the wheel on the balancing flange (flat surface) and the centering surface must be clean.
• Centre (clamp) the wheel from the inside using centering clamping device - see Workshop Equipment Manual, Chapter 3. This centering clamping device fits all wheel-balancing machines approved by Porsche.
• Set required tyre pressure (tyre-pressure plate).
• Centre (clamp) the wheel from the inside using centering clamping device - see Workshop Equipment Manual, Chapter 3. This centering clamping device fits all wheel-balancing machines approved by Porsche.

Check radial and lateral runout during the first measuring run. Values of less than 1.0 mm are desirable - around 0.5 mm would be better.

Consider the size of the measured balancing weights and their distribution on the inner and outer planes (inner and outer rim flanges) critically.

A uniform distribution with low values (e.g. 35g/40g) means that the tyre was fitted correctly and the quality of the tyre and rim is good.

A value of 70g/90g (70g/90g with Tyre Pressure Monitoring) should not be exceeded with interior balancing behind the wheel centre. A considerably different distribution, e.g. 40g/90g is not good; this usually indicates incorrect fitting. Problem wheels of this kind often have pronounced radial and lateral runout values.

This can be remedied by matching (use correct mounting paste). This can be improved with uncontrolled matching (manual); significant improvement is possible in almost all cases using the rolling smoothness optimisation program (controlled matching).

Tyre pressure during balancing at required pressure.

Permissible residual imbalance of max. 8g on the rim flange. Panamera: Permissible residual imbalance of less than 3g, or max. 3g per plane. 

Further to 3: Fitting the wheel on the vehicle 

• Fit wheel using a suitable commercially available tool.
• Screw in wheel bolts by hand and then tighten evenly. Start at the top when tightening. Always observe the specified tightening torque of 160 Nm (118 ftlb.)
• Set required tyre pressure (tyre-pressure plate).