Engine accessory drive belt: 1 - engine crankshaft pulley; 2 - tension roller; 3 - generator pulley; 4 - air conditioning compressor pulley; 5 - auxiliary drive belt
If the belt begins to slip on the pulleys due to wear or oiling, it must be replaced.
Note: It is advisable to use a special measuring device to check the belt tension. A mechanical device determines the applied force at a certain value of belt deflection, while an electronic device measures the frequency of belt oscillations in the area between the pulleys. It should be taken into account that without such devices it is impossible to accurately check the tension of the auxiliary drive belts. With practical experience, you can determine with satisfactory accuracy whether the belt is loose or too tight without using a device. In this case, the accuracy of tension adjustment will depend only on the skills of the performer.
All work related to checking and servicing the accessory drive belt must be carried out in accordance with the maintenance plan (see "Maintenance plan"). In addition, the belt should be checked if signs of insufficient tension appear: a loud squeal when pressing the gas pedal sharply or when turning on powerful energy consumers and the air conditioner.
To restore normal operation of a belt that has been contaminated with oil, you can try treating it with a special cleaner for drive belts. A heavily oiled belt should be replaced.
A faulty tensioner also needs to be replaced. The condition of the tension roller bearing can be assessed by the noise on the running engine using a technical stethoscope. This operation is indicated when checking the technical condition of the engine (see "Engine - technical condition check"). A worn bearing will produce increased noise.
Sequence of execution
1. Prepare the vehicle for work and install it on an inspection ditch or overpass (see "Preparing the car for maintenance and repair"). We switch the gearbox to neutral position.
2. Remove the right front wheel (see "Wheel replacement").
3. Remove the right front mudguard (see "Front mudguard - removal and installation").
4. Using a 17 mm wrench, rotate the crankshaft by the pulley mounting bolt and inspect the auxiliary drive belt from both sides.
Recommendation. The belt must be replaced if cracks, cuts, delamination, protruding cord or peeling rubber are found on its inner or outer side.
Oiling the belt will reduce its service life. The oil leak must be fixed as soon as possible, and the oily belt must be replaced.
5. Using a special device, check the belt tension.
Note: If you do not have a device, you can check the belt tension by pressing it with a force of 98 N (10 kgf) exactly in the middle between the compressor pulley and the engine crankshaft pulley. If it is difficult to estimate the force created by the hand, you can use a household spring balance with a maximum permissible load of 10 kg. A correctly adjusted belt should bend by 6-8 mm.
If the belt deflection is not within the norm, then adjust the belt tension (see "Auxiliary Drive Belt - Replacement"). A loose belt may slip when the load on the auxiliary unit increases or when the crankshaft speed increases sharply. When the belt slips, it begins to wear out rapidly. When the belt is overtightened, its service life is reduced and the load on the auxiliary unit bearings increases.
6. After completing the check, install the removed parts in the reverse order.