Operation CHARM: Car repair manuals for everyone.

General




Excessive wheel imbalance not only produces vibrations and causes the steering wheel to shake, but also results in increased wear on various parts of the running gear.

Even if the wheels are correctly balanced, excessive geometry errors (radial and axial runout) and misshapen tires, e.g. accumulations of material at one point of the tire structure (spring action of tire changes as the tire rolls), can cause rolling and steering imbalance.


NOTE: 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 technical order.
- The wheels must be clean and without foreign objects in the tire.
- Use a tire measuring gauge, e.g. V.A.G 1435, to check axial and lateral runout values on wheels without flat spots. Values less than 1.0 mm better around 0.5 mm - are desirable.
- In order to achieve low radial runout errors or to optimise smoothness of rolling, it is expedient - and necessary in individual cases - to match the tire (i.e. to mount it in a favourable position with respect to the wheel). Tips and mounting instructions, also about tire mounting paste under tires.
- If the rims (wheels without tires) are true but the complete wheels have large axial and radial runout values (due to ply breakage or other damage), tire replacement may be necessary.
- Balance used wheels only after they have been warmed up by driving, otherwise flat spots will simulate imbalance. Never perform matching in the case of flat spots.
- Correct tire pressure is an important prerequisite.
- Place the balancing weights at the prescribed position. Refer to "Balancing weights" for information about putting on the balancing weights.