17:12. Check of a state, adjustment of a tension and replacement of driving belts

Two times a year or each 10 000 km of a run (that will come earlier)

Check of a state

The driving belts sometimes called by belts of V-shaped section or just ventilatory belts are in a forward part of the engine and play an important role in operation of the car and its separate components. Because of features of material and operating conditions driving belts fail after a while and therefore their state it is necessary to check and regulate periodically effort of a tension in order to avoid serious damages of the engine.

The quantity of the belts used on the concrete car depends from installed on it units and systems. Driving belts are applied to actuating of the generator, the steering pump, the water pump and the compressor of the air conditioning system. Depending on an arrangement of pulleys one belt can put in action several components at once.

Switch off the engine, open a cowl and find various driving belts in a forward part of the engine. Fingers (and using a small lamp if it is necessary) walk on all length of each belt, feeling them on existence of cracks and stratifications. Also check whether is not present on belts of attritions and sites, zapolirovanny to gloss. Each belt has to be examined on both sides that means need of its twisting for check of a condition of inner side.
The tension of a belt is checked by strong pressing for it by a thumb and definitions of degree of its deflection. Measure the size of a deflection by a ruler. The rule of a thumb says that if the distance between centers of pulleys makes from 180 to 280 mm, then the size of a deflection has to equal 6 mm. If the distance between centers of pulleys is in limits between 300 and 400 mm, the deflection has to be 13 mm.


In need of adjustment of a tension of a belt towards its increase or reduction it becomes by movement of the unit given by a belt on its fixing arm. In that case when the belt puts more than one unit in action, usually for its adjustment there is enough shift of only one of them.


  1. Each unit has an adjusting bolt and an axial bolt. For its movement on an arm it is necessary to weaken both bolts slightly. For some units the tension of a driving belt can be regulated, turning an adjusting bolt after weakening of a lock bolt.
  1. After both bolts are weakened, displace the unit from the engine for increase in a tension of a belt, or to the engine for its easing.
  2. Fix the unit in new situation and check a belt tension. If further adjustment is not required, twirl both bolts and double-check a tension. If nothing changed, tighten bolts finally.

Often for movement of the unit for the purpose of adjustment of a tension of a belt it is necessary to use the lever. If it is necessary, act extremely carefully not to damage the moved unit or the element used as a point of support.


For replacement of a belt follow the instructions for adjustment given above, but at the same time take off a belt from pulleys.

In certain cases you should take off more than one belt because of features of their arrangement in a forward part of the engine. Therefore and also because belts tends to fail at the same time, it is the best of all to replace them at the same time too. Mark each belt and the flute corresponding to it on a pulley correctly to establish new belts.

Upon purchase of new belts it is convenient to take with itself old to have an opportunity directly to compare them on length, width and design.

Check a tension of new belts after the run of several hundred kilometers.