You will need: a hex wrench “6”, heads “12”, “13”, “14”, a small chisel, a hammer

Drain the engine oil and coolant, remove the mudguard and accessory drive belt

Remove the radiator, fan, coolant pump and generator.

Remove the crankshaft pulley.

The block cover can be removed without removing the head.

But at the same time, damage to the head gasket is possible, since adhesive sealant was applied to the upper end of the cylinder block cover during assembly.

In addition, the head interferes with the installation of the cover - it is difficult to achieve accurate centering of the cuff on the crankshaft sleeve, which will lead to its rapid wear.

Therefore, when disassembling the gas distribution mechanism drive, we remove the block head (see Cylinder Head Gasket ZMZ-406).

ZMZ-406 chain replacementZMZ-406 chain replacement

With a “14” head, we unscrew the four bolts securing the clutch crankcase amplifier to the block.

With the keys "14" and "17" we unscrew the two bolts securing the amplifier to the clutch housing and remove the amplifier.

ZMZ-406 chain replacementZMZ-406 chain replacement

With a “13” head, we unscrew four nuts and a “12” key with eleven bolts securing the oil pan to the cylinder block.

ZMZ-406 chain replacementZMZ-406 chain replacement

Carefully, trying not to damage the gasket, remove the pallet from the studs and put it on the beam.

Remove the lower chain hydraulic tensioner (see ZMZ-406 engine chain hydraulic tensioner).

ZMZ-406 chain replacement ZMZ-406 chain replacement

Using a 6" hex wrench, we unscrew the seven screws securing the cylinder block cover.

Prying off with a screwdriver, remove the cover.

ZMZ-406 chain replacementZMZ-406 chain replacement

Using a 6" hex wrench, we unscrew the axle of the upper chain tensioner shoe

ZMZ-406 chain replacementZMZ-406 chain replacement

Remove the tensioner shoe.

Remove the upper chain from the intermediate shaft sprocket.

ZMZ-406 chain replacementZMZ-406 chain replacement

If necessary, use the “14” key to unscrew the shoe axle extension.

Using a “6” hex wrench, we unscrew the axle of the lower hydraulic tensioner shoe and remove the shoe.

ZMZ-406 chain replacementZMZ-406 chain replacement

Bend the edges of the locking plate with a chisel.

With a screwdriver, holding the intermediate shaft sprocket, unscrew the two bolts with the “12” key.

ZMZ-406 chain replacementZMZ-406 chain replacement

Remove the sprocket along with the lower chain from the axis of the intermediate shaft.

Using a 6" hex wrench, unscrew the two screws and remove the lower chain damper.

We assemble in the reverse order.

Before assembling the timing drive, we clean the mating surfaces of the cylinder block and the chain cover from the remnants of the gasket and sealant.

Install

If filmed crankshaft gear, press it onto the crankshaft, install the O-ring and bushing

ZMZ-406 chain replacement

Install key 1 in the groove on the crankshaft.

Turn the crankshaft so that mark 3 on the crankshaft gear aligns with 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.

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

ZMZ-406 chain replacement

Put the chain on the driven gear 1 and install it on the intermediate shaft 2 so that the wheel locating pin fits into the hole

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.

ZMZ-406 chain replacement

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

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

In this case, the pin 8 of the camshaft must enter the hole of the gear. Screw in bolt 1.

You need to turn the camshaft with a key for the square on the camshaft.

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

The intermediate and crankshafts must not rotate. Mark A must coincide with the upper 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. By slightly turning the camshaft counterclockwise, tension the chain.

Mark "A" 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, apply a thin layer of Germesil sealant or similar to the surfaces of the cover adjacent to the cylinder block and block head.

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

Install the upper and lower chain tensioners.

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 if labels match.

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

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

Install all parts in reverse order.