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8.5.7. Wheel imbalance

Fig. 7.34. Wheel imbalance: and – in a statics; – in dynamics

The imbalance of wheels is felt on vibrations on a steering wheel or jolting of a forward part of the car. Both it is especially strongly shown at certain speeds. The reason of it is uneven distribution of weight on a wheel. Distinguish a wheel imbalance in a statics and in dynamics. The imbalance in a statics is shown when freely suspended rotating wheel constantly is shaken on the same place (fig. 7.34, a). Such wheel will jump at the movement, and shock-absorbers wear out quicker.
The imbalance in dynamics is shown when the wheel is located at an angle to an axis (fig. 7.34, b). At high turns it has hesitations and rocking.

Wheel imbalance
At emergence of an imbalance first of all it is necessary to wash carefully wheels, especially from the inside. Perhaps, after it the cause will be removed.
Exact balancing is recommended, at least, for forward wheels as even their slightest imbalance is felt on a steering wheel. Balancing of back wheels directly on the car is dangerous. The differential can be damaged. Therefore wheels have to is put in action by the engine.

Therefore wheels in a statics and dynamics demand balancing. For this purpose there are two methods:
1. The wheel is removed from the car and privorachivat on the special balancing stand. The wheel rotates on it, and places of an imbalance are specified. Alignment of an imbalance is carried out by an attachment of special balancing small weights on a wheel.
2. More exact final balancing is sometimes applied. For this purpose the forward wheels which are already established on the car with a necessary speed rotate at the stand by means of the contact shaft given by the electric motor. The shown places of an imbalance also level by means of small weights. However Mercedes considers this procedure excessive as wheels of the released cars are very well centered.
Balancing — a difficult task. It is necessary to be limited as it is possible smaller quantity of small weights that, perhaps, will demand numerous shift. Tires with a beating on height more than 1 mm and side — more than 1,6 mm do not give in to final balancing. Same treats tires with the damaged framework, for example, owing to arrival at great speed on a border or other obstacle.