General information on balancing/optimizing wheels
Excessive rough running of the wheels, caused by wheel imbalance, flat spots and securing the wheel on the vehicle, causes vibrations and shaking in the steering wheel. This in turn leads to increased wear on various parts of the chassis.
Even if wheels are correctly balanced, rolling and steering imbalance can still occur. E.g.:
- excessive geometric errors (radial and lateral runout),
- radial force variations (softer and more rigid areas in the tyre).
- Achieving a good result requires utmost care, observance of the instructions and procedure, and attempting to eliminate even the very last gram of imbalance .
Recommendations/prerequisites:
Wheel suspension elements must be in good working order. The wheels must be clean with no foreign objects in the tyre.
Use a tyre measuring gauge, e.g. measuring gauge Nr.136 to check radial and lateral runout values on wheels without flat spots. Values of less than 1 mm are desirable -around 0.5 mm would be better.
To limit the number of radial runout errors and to optimise rolling smoothness, it is a good idea - and even necessary in some cases - to match the tyre (i.e. to fit it at a favorable position with respect to the rim). Follow tips and fitting instructions as well as information on tyre mounting paste for tyre.
If the disc wheels (wheels without tyres) are perfect but the complete wheels have large radial and lateral runout values (due to ply breakage or other damage), it may be necessary to replace the tyre.
Balance used wheels only after they have been warmed up by driving, otherwise flat spots will simulate imbalance. Never perform matching on wheels with flat spots. In the event of flat spots, wheels must be warmed up by driving 25 - 30 km (16 - 20 miles) on a motorway. Lift up the vehicle immediately on return. This prevents new flat spots from forming.
Correct tyre pressure is an important prerequisite.
Place the balancing weights at the prescribed position.
On wheel balancing machines with vibration control system (Vibration control system WE 1296 ), the radial force variation value must be set in the machine's basic settings as follows:
- Porsche Cayenne: 120 N
- All other models: 80 N