Adjusting the tension of MAZ car drive belts
The drive of the water pump, compressor and generator is carried out by V-belts, on the reliable operation of which the normal operation of these units depends
Therefore, in the daily care of engines, protect the belts from oil and fuel, control their tension and adjust it.
Check the belt tension especially carefully during the first 50 hours of engine operation, as this is when they are most stretched.
The tension of the belts should always be normal, since both excessive and insufficient tension leads to premature failure.
Also, over-tensioning the water pump drive belt can cause damage to the pump bearings.
A normally tensioned water pump belt, when pressed on the middle of a long branch with a force of 40 N (4 kgf), bends by 7-12 mm (Fig. 1)
or 10-15 mm (fig. 2), and the compressor belt - by 4-8 mm on a short branch (fig. 3)
Check the tension of the generator drive belts by pressing with a force of 40 N (4 kgf) on the middle of the branch of each belt (Fig. 4), while the generator drive belts should bend by 10 - 15 mm.
If the belts flex more or less than specified, adjust their tension.
Adjust the tension of the water pump belt of the YaM3-2Z6NE, NE2, BE, BE2 engines (Fig. 1) with a tensioner, for which:
- - loosen the bolts of the tensioner bracket lever;
- - using a Ø12 mm knob inserted into the hole in the lever of the tensioner bracket, tension the belt;
- - without loosening the tension force, tighten the bolts of the tensioner bracket lever;
- - check belt tension.
Adjust the tension of the water pump belt of the YaMZ-236N, B engines with gaskets (Fig. 5).
To tension the belt, unscrew the nuts securing the pulley sidewall and remove one or two shims (Fig. 5).
Place the spacers on the outer side of the sidewall and tighten the nuts sequentially, in several stages, turning the pulley after tightening each nut.
Then check that the belt tension is correct.
When replacing an old belt, place all spacers between the hub and the removable pulley sidewall and adjust the belt tension as indicated above.
Adjust the tension of the compressor belt with a tensioner.
Before adjusting, loosen the lock nut one turn, the tensioner pulley axle nut half a turn, and the tensioner bolt nut two turns.
Turn the tensioner bolt to adjust the belt tension.
After adjustment, tighten the axle nut and locknut to a torque of 120-150 Nm (12-15 kgcm) and the tensioner bolt nut to a torque of 10-20 Nm (1-2 kgcm), with a larger tightening torque, the adjustment will be violated due to movement of the pulley axis.
Adjust the tension of the alternator drive belt by moving the alternator relative to the axis of its attachment.
Before adjusting, loosen the alternator mounting bolts, the alternator bar mounting nut and the alternator mounting bolt to the bar.
Fix the generator securely after adjustment.
If the exhaust is increased and at least one of the alternator drive belts is broken, replace both belts with a set to ensure a uniform load on them.