Camshaft drive chain, two-stage

Includes: crankshaft sprocket (23 teeth), intermediate shaft driven and driven sprockets (38 and 19 teeth), camshaft sprockets (23 teeth), two reinforced bush chains (72 links - lower and 92 links - upper ), hydraulic tensioners, tensioner levers, and chain dampers.

The chain tension of each stage is carried out by hydraulic tensioners located: the lower chain - in the chain cover, the upper chain - in the cylinder head.

Remove

Camshaft drive ZMZ-406

Remove the oil filler cap 1.

Remove the 2 spark plug caps with the 3 high voltage wire seals and wires.

Disconnect hose 5 and tube 7 of crankcase ventilation from fittings on cover 6 of the block head.

Unscrew the eight bolts 4 and remove the head cover 6 with the cover gasket.

Camshaft drive ZMZ-406

Remove the four bolts 1 and remove the front cover 2 of the block head, being careful not to damage the gasket.

Remove bolts 3 and remove plastic guide 4 for the chain.

Camshaft drive ZMZ-406

Set the piston of the 1st cylinder to top dead center (TDC) of the compression stroke.

To do this, turn the crankshaft by ratchet 1 so that mark 2 on the crankshaft pulley coincides with protrusion 3 on the cover.

Camshaft drive ZMZ-406

In this case, marks 1 on the camshaft sprockets should be located horizontally at the level of the upper plane of the block head and directed in opposite directions.

After installing the piston of the 1st cylinder in the top dead center do not turn the camshafts, crankshaft and intermediate shaft.

Camshaft drive ZMZ-406

Remove the water pump.

Remove the generator.

Unscrew ratchet 1 while holding the crankshaft from turning by inserting a screwdriver between the teeth of the flywheel and resting it on the pin for installing the clutch housing.

Using a puller, press pulley 2 off the crankshaft.

Remove bolts 3 and remove cover 4 of the lower chain hydraulic tensioner with gasket.

Remove the cover carefully, as it is affected by the force of the hydraulic tensioner spring.

Then remove the hydraulic tensioner.

Camshaft drive ZMZ-406

Unscrew the bolts and nuts securing the crankcase, remove the crankcase and crankcase gasket.

Remove the seven bolts and remove the chain cover. Remove the cover carefully so as not to damage the front crankshaft oil seal installed in it, the cover gaskets and the cylinder head gasket.

Unscrew bolts 1 and remove cover 2 of the upper chain hydraulic tensioner.

The cover must be removed carefully, as it is affected by the force of the hydraulic tensioner spring.

Then remove the hydraulic tensioner.

Remove bolts 4 and pull chain guide 3 upwards.

Bend the ends of the locking plate 8 and unscrew the bolts 7, while keeping the intermediate shaft from turning by inserting a screwdriver into the hole of the gear wheel 5.

Remove gear wheel 6 by inserting a screwdriver between gear wheels 5 and 6 and resting it like a lever against wheel 6.

Remove the gear wheel 6 from the upper chain and then remove the chain by pulling it up.

Remove gear 5 from the intermediate shaft and remove it from the lower chain.

Remove the lower chain from the crankshaft sprocket.

If it is necessary to remove the camshaft gears, you need to unscrew the bolts securing them to the camshaft flanges.

Camshaft drive ZMZ-406

If it is necessary to remove the gear wheel 1 from the crankshaft, you must first remove the bushing 2 and the rubber sealing ring between the bushing 2 and the wheel 1.

Then press gear 1 with a puller

Inspection

After removing, wash the chains and gears in gasoline, wipe and dry.

Inspect the chains. If the chain bushings are cracked, chipped, or have significant signs of wear, replace the chains.

Toothed colessa, which have chips on the teeth, chipping, as well as those with broken teeth, must be replaced.

Replace damaged chain guides.

The tensioner shoes must rotate freely on the axles.

If they have cracks, chips or significant wear on the working surface, they must be replaced.

Installation

If the crankshaft gear was removed, press it onto the crankshaft, install the O-ring and bushing.

Camshaft drive ZMZ-406

Install key 1 in the groove on the crankshaft.

Turn the crankshaft so that mark 3 on the crankshaft gear matches mark 2 on the cylinder block.

In this case, the piston of the 1st cylinder will take the position of the top dead center

Install the chain damper 4, but do not tighten the bolts 5 for fastening the damper.

Place chain 6 on the crankshaft gear, after lubricating it with engine oil.

Camshaft drive ZMZ-406

Put the chain on the driven gear 1 and install it on the intermediate shaft 2 so that the wheel locating pin enters the hole in the intermediate shaft.

In this case, mark 4 on the gear wheel must coincide with mark 5 on the cylinder block, and the chain branch passing through the damper 3 must be tensioned.

Install the countershaft drive gear so that its locating pin fits into the hole on the driven gear.

Tighten the two bolts securing the intermediate shaft gears, placing a locking plate under them.

Tighten the bolts to a torque of 22–25 Nm (2.2–2.5 kgf m) and fix them by bending the edges of the locking plate on the edges of the bolt heads.

After installing the chain, do not turn the intermediate and crankshafts.

Pressing the tensioner shoe, tighten the chain and check the alignment of the marks on the gears and the cylinder block.

Tighten the chain guide bolts.

Lubricate the upper chain with engine oil and then put it on the countershaft drive gear, passing it through the hole in the block head.

Camshaft drive ZMZ-406

If the gear wheel 2 is mounted on the camshaft, unscrew the bolt 1 and remove the wheel 2 from the camshaft.

Put the chain on the gear wheel 2 and, slightly turning the exhaust camshaft clockwise, install the gear wheel 2 with the chain on it.

In this case, the camshaft pin 8 must enter the gear hole.

Tighten bolt 1.

Turn the camshaft with the key on the square on the camshaft.

Then, turning the camshaft slightly counterclockwise, tension the chain.

The intermediate and crankshafts must not turn while doing this.

The "A" label must match the top plane of the block head.

Remove bolt 6 and remove gear wheel 4 from the intake camshaft.

Put a chain on wheel 4 and install wheel 4 with chain on the camshaft, while slightly turning the camshaft clockwise.

Camshaft pin 5 must fit into the gear hole.

Slightly turn the camshaft counterclockwise to tension the chain.

The mark "А" on the gear wheel 4 must coincide with the upper plane of the head of the block.

The rest of the shafts must not rotate.

Tighten bolt 6.

Tighten bolts 1 and 6 to 46–74 Nm (4.6–7.4 kgf m), while holding the camshafts from turning with a wrench on the squares.

Install damper 3 by pushing it into the hole in the block head. Install damper 7.

Install the chain cover and water pump. At the same time, on the surfaces of the cover adjacent to the cylinder block and block head, apply a thin layer of Hermesil sealant or similar.

When installing the chain cover, take care not to damage the crankshaft oil seal.

Install the hydraulic tensioners for the upper and lower chains.

Install the crankshaft pulley.

Turn on the ratchet and tighten to a torque of 104–128 Nm (10.4–12.8 kgf m), holding the crankshaft from turning by inserting a screwdriver into the teeth of the flywheel crown and resting it on the clutch housing locating pin.

When tightening the ratchet, the flywheel pulley is pressed onto the crankshaft.

Crank the crankshaft two turns by the ratchet and set it to the TDC position. piston of the 1st cylinder.

Check label matches.

Install the front cover of the block head by applying to the surface of the cover, adjacent to the block head, a layer of Hermesil sealant.

Tighten the cover bolts to 12–18 Nm (1.2–1.8 kgf m).

Install the generator.