The drive belt used in cars drives the auxiliary units of the internal combustion engine. Due to the rotation of the crankshaft, it transmits torque, ensuring the operation of the attachment. The drive belt has its own resource, different lengths, a different number of rivulets and teeth.
Drive belt function
The drive belt is necessary to transmit torque from the crankshaft, thanks to which the auxiliary units rotate. Torque transmission is carried out by friction (poly V-belt) or engagement (toothed belt). From the belt drive, the work of the generator was activated, without which it is impossible to charge the battery and maintain a constant voltage of the on-board network. The air conditioning compressor and the power steering pump are also driven by a belt drive. In some cases, the water pump is also driven by a toothed belt (1.8 TSI VAG engine).
Service life of drive belts
Due to the design features (elasticity and flexibility), the average belt life is 25 operating hours or 000 kilometers. In practice, belt life may vary in one direction or another, depending on the following factors:
- belt quality;
- the number of units driven by one belt;
- wear of the crankshaft pulley and other units;
- belt installation method and correct tension.
Regular check of drive belts
Periodic belt tension checks should be done every season. Belt diagnostics are performed with the engine off. The tension level is checked by pressing a finger, while the deflection should not be more than 2 cm. A visual inspection reveals the presence or absence of cracks. At the slightest damage, the belt must be replaced, otherwise it may break at any time.
Also, the belt is checked in individual cases:
- insufficient battery charge;
- the steering wheel (in the presence of a hydraulic booster) began to rotate tightly, especially in a cold season;
- the air conditioner is cold;
- during the operation of auxiliary units, a creak is heard, and when water gets on the belt, it turns.
When and how to change the drive belt
The drive belt must be changed according to the regulations specified by the manufacturer, or if the above factors of belt wear are present. The minimum belt resource is 50000 km, wear at a lower mileage indicates a backlash in one of the drive pulleys or poor belt quality.
Depending on the engine modification and the design of the accessory drive, change the belt yourself. The difference lies in the type of tension:
- bolt tension
- tension roller.
Also, the units can be driven by one belt, or individually, for example: a car Hyundai Tucson 2.0 is equipped with air conditioning and power steering pump, each of which has an individual belt. The power steering pump belt is driven from the generator pulley, and the air conditioner from the crankshaft. The air conditioner belt is tensioned with a roller, and the generator and power steering pump are tensioned with a bolt.
The process of replacing drive belts using the example of Hyundai Tucson:
- the engine must be off, the gearbox selector must be in the “P” mode or in 5th gear with the handbrake on;
- the front right wheel must be removed to access the crankshaft pulley;
- to access the KV pulley, remove the plastic boot that protects the belts from dirt;
- under the hood, the power steering pump belt is the first to get, for this you need to loosen the fastening and bring the pump closer to the engine;
- the alternator belt is removed by loosening the fastening, similar to the power steering pump;
- the last to remove the belt on the air conditioner compressor, here the tension is made by a roller, which is bolted on the side, and depending on the tightening force of the bolt, the belt tension is adjusted; just slightly unscrew the bolt and the belt will weaken;
- the installation of new belts is carried out in the reverse order; put the boot back last after checking the operation of the belts.
Pay special attention to the quality of the products, try to purchase original spare parts, in order to avoid the risk of premature wear.
How to tension, tighten or loosen a drive belt
Using the same example:
- the air conditioner belt is tensioned by a roller mechanism using a side bolt that moves the roller back and forth; to tighten the bolt, turn clockwise, to loosen it counterclockwise (deflection of the new belt is no more than 1 cm);
- the alternator belt is tensioned with a special long screw, when tightened, the alternator moves back, creating a tension, in the opposite direction the belt is loosened
- to tighten or loosen the power steering pump belt, you need to loosen the assembly mounting bolt, select the required tension and tighten the bolt, if there is not enough tension, use a pry bar and rest between the engine and the pump, moving the pump forward in the direction of the car.
Why did the belt whistle
Belt whistling occurs for the following reasons:
- when driving, water got on the belts, turning relative to the pulley occurred;
- malfunction of the bearings of the generator or the power steering pump, increase the load on the belt;
- insufficient tension or vice versa;
- poor quality product.
If the belts are in good condition, but there is a squeak from time to time, it is recommended to purchase a spray conditioner that tightens the belt, extending its life.