Replacing chains and gears of the gas distribution mechanism ZMZ 406 GAZ-2705

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

Drain the cooling system.

Replacement of chains and gears of the gas distribution mechanism ZMZ-405

Remove the cooling system radiator Gazelle Radiator

Remove the power steering pump drive belt and fan pulley Removing the ZMZ 406 GAZ-2705 alternator belt

Remove the alternator and water pump drive belt.

Replacement of chains and gears of the gas distribution mechanism ZMZ-405Replacement timing chains and gears ZMZ-405

Loosen the inlet hose clamp and remove the hose.

Remove the cylinder head cover.

Replacement of chains and gears of the gas distribution mechanism ZMZ-405Replacement timing chains and gears ZMZ-405

Remove the four bolts and remove the front cylinder head cover assembly with fan drive clutch and fan (viscous clutch with fan removed for clarity).

Remove the water pump.

Replacement of chains and gears of the gas distribution mechanism ZMZ-405

Replacement of chains and gears of the gas distribution mechanism ZMZ-405

Remove the crankshaft speed sensor (timing sensor).

Remove the crankshaft pulley.

Remove the oil pan.

Remove the two bolts and remove the upper chain tensioner cover with gasket. Remove the cover carefully, as the hydraulic tensioner spring acts on it.

Then remove the hydraulic tensioner.

Replacement of chains and gears of the gas distribution mechanism ZMZ-405Replacement timing chains and gears ZMZ-405

Remove the lower chain tensioner in the same way.

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.

Remove the top tensioner bolt and remove the sprocket tensioner arm.

Remove the lower sprocket tensioner arm in the same way.

Remove the two bolts and remove the plastic chain guide.

Replacement of chains and gears of the gas distribution mechanism ZMZ-405

Remove the gears from the camshafts by removing the bolts securing the gears to the camshaft flanges.

Replacement of chains and gears of the gas distribution mechanism ZMZ-405

Remove the bolts 2 and pull up the chain guide 1.

Unbend the ends of the locking plate 6 and unscrew the bolt 5, to do this, keep the intermediate shaft from turning by inserting a screwdriver into the hole of the gear 3.

Remove gear 4 by insertinga screwdriver between it and gear 3 and resting with a screwdriver as a lever against gear 3.

Remove gear 4 from the top chain and remove the chain by pulling it up.

Remove gear 3 from the intermediate shaft and remove it from the lower chain. Remove the lower chain from the crankshaft gear.

Replacement of chains and gears of the gas distribution mechanism ZMZ-405

If it is necessary to remove gear 2 from the crankshaft, first remove bushing 1 and the rubber o-ring between bushing and gear. Then press gear 2 with a puller.

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

Inspect the chains. If cracks, chips, or significant signs of wear are found on the chain bushings, replace the chains.

Replace gears that have chipped or chipped teeth.

Replace damaged chain guides.

The tensioner sprockets must rotate freely on the axles. If the sprocket teeth are chipped or chipped, replace the tensioners.

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

Replacement of chains and gears of the gas distribution mechanism ZMZ-405

Turn the crankshaft so that mark 1 on the crankshaft gear matches mark 2 on the cylinder block.

In this case, the piston of the 1st cylinder will take the TDC position.

Install the chain damper 4 without tightening the bolts 3 fastening the damper.

Put chain 5 on the crankshaft gear after lubricating it with engine oil.

Replacement of chains and gears of the gas distribution mechanism ZMZ-405

Put the chain on the driven gear 1 and install the gear on the countershaft 2 so that the pinion of the gear fits into the hole of the countershaft.

In this case, mark 4 on the gear 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 in the driven gear.

Install the two countershaft gear bolts with a lock plate underneath them.

Tighten the bolts to 22–25 N m (2.2–2.5 kgf m) and secure them by bending the edges of the lock plate on the edges of the bolt heads.

Replacing chains and gears of the gas distribution mechanism ZMZ-405

While pressing the tensioner lever, tighten the chain and check the alignment of the marks on the gears and the cylinder block.

Tighten the chain guide bolts.

Lubricate the top chain with engine oil and then slide it over the countershaft drive gear through the hole in the cylinder head

Replacing chains and gears of the gas distribution mechanism ZMZ-405

Place the chain on gear 2 and turn the exhaust camshaft slightly clockwise to install gear 2 with the chain on it. Pin 8 of the camshaft must fit into the gear hole.

Install bolt 1. Turn the camshaft with a wrench at the square on the camshaft. Then, slightly turning the camshaft counterclockwise, tension the chain.

The intermediate and crankshafts must not rotate. Mark "A" must match the top surface of the cylinder head.

Remove bolt 6 and remove gear 4 from the intake camshaft. Put a chain on gear 4 and install gear 4 with chain on the camshaft by slightly turning the camshaft clockwise.

Camshaft pin 5 must fit into the gear hole. By slightly turning the camshaft counterclockwise, tension the chain.

The "A" mark on gear 4 must align with the top surface of the cylinder head. The rest of the shafts should not rotate.

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

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

Install the circuit cover and water pump . Apply a thin layer of sealant to the surfaces of the covers adjacent to the cylinder block and block head.

When installing the chain cover, be careful not to damage the crankshaft oil seal.

Install the upper and lower chain tensioners. Install the crankshaft pulley.

Install the crankshaft pulley bolt, then, engaging fifth gear and braking the car with the parking brake, tighten the bolt to 104–128 Nm (10.4–12.8 kgf m), while holding the crankshaft from turning.

When the ratchet is tightened, the pulley is pressed onto the crankshaft.

Crank the crankshaft two turns by the ratchet and set the piston of the 1st cylinder to the TDC position (see operation 3). Check if the tags match.

Install the front cover of the cylinder head, first apply a layer of 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 the cylinder head cover.

Tighten the cover bolts to 6.0–12 Nm (0.6–1.2 kgf m).

Connect the crankcase ventilation hose and tube to the fittings on the valve cover, and the wires to the ignition coils. Put the tips of the high-voltage wires on the spark plugs.

Install the previously removed attachments.