Toothed belt tension is an important adjustment factor that ensures long belt life, no slippage of the pulley teeth and quiet operation. Toothed belt tension is checked and adjusted when the engine is cold (engine and ambient temperature 15-30°C.
To tension the belt, place the gear lever in neutral, open the hood, and remove the spare wheel and front toothed belt guard. Turn the crankshaft 1.5-2 turns for the bolt securing the alternator drive pulley clockwise until the flywheel mark is aligned with the middle scale mark on the clutch housing (see fig. 67). In this case, the marks on the camshaft pulley and the rear protective cover of the belt must be aligned (see fig. 7).
Turn the crankshaft only in the direction of tightening the bolt (clockwise). When tensioning the belt, it is not allowed to turn the crankshaft by rotation of the camshaft pulley or its fastening bolt.
Check belt tension. It is considered normal if, in the middle part of the branch between the pulleys of the camshaft and crankshaft, the belt is twisted along 90°with a finger force of 15-20 N. If the force is below normal, loosen the tension roller axis fastening nut, turn the axis by the hexagonal head by 10-15°counterclockwise and lightly tighten the axle nut.
Again turn the crankshaft clockwise two turns and check the belt tension. If the tension is not enough, then repeat the operation to tension the belt. If the tension is normal, then finally tighten the tension roller axle nut to a torque of 39.2 N·m, install the front protective cover of the toothed belt and the spare wheel.
When adjusting, excessive belt tension should not be allowed, as this significantly reduces its service life.