The timing belt of the VAZ-2112 engine is reinforced compared to the VAZ-2110, 2109 engines.
It is wider in size due to increased loads
The belt drives the two camshafts, the intake and exhaust valve shafts, and the coolant pump.
The toothed pulleys and rollers are also wide, to match the width of the belt.
Belt width 25.4 mm.
For the correct installation of the timing belt, and for setting the TDC, there are marks on the camshaft pulleys and on the rear cover of the camshaft drive.
Accordingly, there is also a mark on the crankshaft pulley and on the oil pump.
The design of the engine does not provide for a sudden break in the belt.
If the belt suddenly breaks, the pistons can hit the valves.
Therefore, it is necessary to carefully inspect the condition of the belt during periodic maintenance.
For ease of inspection, a hatch is provided in the upper timing belt cover.
To inspect the condition of the belt, pry the hatch with a screwdriver
We examine the condition of the belt, while it is better to scroll the crankshaft to inspect the entire belt
The following modifications of the VAZ-21124, VAZ-21126 engines already have grooves in the pistons that protect the pistons and valves from impact.
Recesses in the pistons of the VAZ-2112 engine
Recesses in the pistons of the VAZ-21124 engine
To replace the timing belt, you must first remove the alternator drive belt to do this:
Using a 13 key, we loosen the tightening of the nut securing the generator to the tension bracket
With a 10 key, we unscrew the adjusting bolt and loosen the belt. We remove it from the pulleys of the crankshaft and generator
With a head of 10, we unscrew the six bolts securing the front cover
Remove the timing belt cover
With a 17 key, turn the crankshaft clockwise for the bolt securing the alternator drive pulley
Turn until the mark on the flywheel and the clutch housing cover align.
In this case, the marks on the toothed pulleys of the camshafts must match the marks on the rear timing belt cover
To unscrew the bolt securing the generator drive pulley, we fix the flywheel from turning with a screwdriver
Using a 17 socket or a spanner wrench, unscrew the pulley mounting bolt
Remove the alternator drive pulley
On the crankshaft pulley, when setting the TDC, the mark must match the slot on the oil pump
Using a 17 key, loosen the nut of the timing belt tensioner
By turning the roller, we loosen the belt tension and remove its rear branch from the gear pulley of the exhaust camshaft, the tension roller and the coolant pump pulley.
Remove the belt from the toothed pulleys of the crankshaft and exhaust camshafts and the support roller.
Install the belt in reverse order.
We make sure that the alignment marks of the crankshaft and camshafts are aligned.
We put the toothed belt on the crankshaft pulley.
By turning the tension roller, we tighten the belt and fix the roller
When tensioning the belt, the notch on the outer disc must align with the protrusion on the inner hub of the idler
By turning the crankshaft two turns in the direction of rotation, we check the alignment of the alignment marks.
We check the tension of the toothed belt in the middle part of the branch between the camshaft pulleys.
The deflection of the belt should be 5.4±0.2 mm under a load of 100 N (10 kgf).
Assemble the parts in reverse order.
The tightening torque of the bolt for fastening the alternator belt drive pulley is 97.9.108.8 Nm (9.90 - 11.10 kgf.m)