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Poly V-belt: replacement and selection

When and why it is necessary to replace poly V-belt

Lifetime limit of the multi-rib belt is about 70 000 – 80 000 kilometers of mileage. At the same time, regardless to mileage its expiry date is about 5 years from the manufacture date, even if the part wasn’t used. Cracks, de-layering and abrasion of ribs and cord fibers can be noticed on a worn component. Apart from wear-out, its oiling can become the cause of improper operation of the part. Premature breakdown of the serpentine belt can be caused by its improper installation, particularly, insufficient tensioning, as well as defectiveness of rollers, pulleys and other drive elements.

You can understand that the multi-rib belt is defective by whistling sound from under the bonnet during driving. Often, this sign points out that the part is stretched and slipping on the pulleys. Tearing of the item usually comes with loud clap. In this case, operation of the equipment, which gained torque from the belt, stops and the indicator, signing about the fault, activates on the dashboard. One should take into account that the whistling sound after driving through a puddle or at heavy rain may follow operation of a non-faulty belt: in this case, the part temporary loses contact with the pulley due to moisture effect.

It is advisable to replace the part together with the tensioner and idler rollers. Procedure should be performed at a service station, because this work comes with removal of many components. Moreover, it is necessary to tighten a new belt properly. Such works require high qualification.

How to choose poly V-belt

The automotive drive belts differ by cross-section. For example, profile of the V-belt has trapezoidal shape. The double-groove belt is a double V-shaped belt. The six-ribbed belt has cross-section in the shape of six wedges at low profile height, which provides good contact with the pulleys and significant flexibility at the same time. Due to this, the part is more durable. Such parts are used on many middle-class cars. Vehicles of business and executive classes may have components with 10 wedges.

Hi-Tec poly-ribbed belts, notable for continuous lifetime are offered by well-known manufacturers, such as Contitech, Bosch, Dayco, SKF, Gates.

You should take V-ribbed belt markings into account during selection. Manufacturers use the next markings: PH, PJ, PK, PL and PM. Parts with different identification marks are different from one another by sizes, section parameters, minimum pulley diameter and maximal rotation speed. It is important to consider that the characteristics, matching to markings are not equal from different manufacturers, that is why you need to specify compatibility of various brands items during purchase.

Buying a drive belt, specify its manufacturing date. In the course of time, chemical contents of materials are changing, and the part, which useful time in ended, should be regarded defective.