The piston of the 1st cylinder is set to the position of the top dead center (TDC) of the compression stroke so that when carrying out work related to the removal of the timing chains, the installation of the gas distribution phases is not disturbed

If the valve timing is disturbed, the engine will not work normally.

Remove the oil filler cap 1.

How to set the TDC of the ZMZ-405 and ZMZ-406 engines

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.

How to set the TDC of the ZMZ-405 and ZMZ-406 engines

Unscrew 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.

How to set the TDC of the ZMZ-405 and ZMZ-406 engines

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

How to set the TDC of the ZMZ-405 and ZMZ-406 engines

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.

If the marks on the gears of the crankshaft and on the gears of the camshafts do not match, then the installation of the gas distribution phases is violated (the piston of the first cylinder is not set to TDC)