You will need: a screwdriver, keys "8", "10", "13", a special key for turning the crankshaft
Setting the piston of the fourth cylinder to the TDC position of the compression stroke
The piston of the 4th cylinder is set to the TDC (top dead center) position of the compression stroke so that when carrying out work related to the removal of the camshaft drive chain, the installation of the valve timing is not disturbed.
If the valve timing is disturbed, the engine will not work normally.
Set the TDC according to the mark on the camshaft sprocket (when installing according to the marks on the crankshaft pulley and on the front cover of the camshaft drive chain, either the 1st or 4th piston can be in this position cylinder).
After this, make sure that the marks on the crankshaft pulley and cover match.
If the shaft marks do not match, then the valve timing is incorrect (the piston of the 4th cylinder is not set to TDC).
In this case, it is necessary to remove the camshaft drive chain from the camshaft sprocket and turn the crankshaft until the marks align.
Turn the crankshaft the shaft can be turned in the following ways.
Purchase a special key for turning the crankshaft by the pulley mounting nut.
This key can also be used to turn the crankshaft from above the engine compartment.
On a car without air conditioning, the crankshaft can be turned with a special open-end wrench or a 38 mm head by the accessory drive pulley mounting nut.
On a car with air conditioning, the crankshaft cannot be turned in this way, because that in addition to the accessory drive pulley, the nut also secures the air conditioning compressor drive pulley.
In this case, you cannot use an open-end wrench, because the nut is located deep in the pulley, and when using a socket head, there is not enough space to install the ratchet - it rests against the radiator frame spacer.
In this case, we set the crankshaft to the desired position by moving the car in fourth or fifth gear.
Engage 4th gear and slowly roll the car in the desired direction until the mark on the camshaft sprocket matches the mark on the camshaft bearing housing.
Engage 4th gear and hang up one of the rear wheels.
Then turn the hung wheel in the desired direction until the mark on the camshaft sprocket matches the mark on the camshaft bearing housing. shaft.
Location of TDC marks
The marks are located on the camshaft sprocket (hole "a") and on the camshaft bearing housing (protrusion "b").
The risk mark on the toothed rim of the auxiliary drive pulley should be located opposite the core of the crankshaft position sensor
Remove the cylinder head cover (see. "Replacing the head cover gasket Niva Chevrolet").
Rotating the crankshaft, align the marks on the camshaft sprocket and on its bearing housing.
If the chain is installed correctly, the mark on the crankshaft pulley should match the long mark on the camshaft drive chain cover.
If the marks do not match, bend the tabs of the bolt lock washer camshaft sprocket fastenings.
Engage first gear to secure the crankshaft from turning, unscrew the bolt and remove it together with the lock and thrust washers.
The lock and thrust washers are not fixed on the bolt in any way and can be easily removed from it.
Be careful - do not drop them into the engine sump.
Remove the chain tensioner (see "Replacing the tensioner Niva Chevrolet").
If you have the necessary skills, you can leave the hydraulic tensioner in place.
It is enough to press the plunger of the hydraulic tensioner with a large screwdriver or a mounting blade.
Remove sprocket together with the chain, remove the chain from the sprocket and then reinstall it on the sprocket, changing the position of the chain on the sprocket teeth in the desired direction.
It is recommended to move the chain one tooth at a time.
Put the sprocket together with the chain on the flange of the camshaft, tightening the leading branch of the chain.
Since when changing the position of the chain on the sprocket, the hole in the sprocket no longer coincides with the installation pin in the flange, turn the crankshaft slightly in the desired direction until the hole and pin match.
Install the sprocket mounting bolt together with the thrust and lock washers and tighten it until it stops, without tightening it completely.
After turning the crankshaft two turns, repeat the check of the position of the marks, as you did before.
If the marks match, tighten the bolt and bend the tab of the lock washer onto the edge of its head.
If the marks do not match, repeat the valve timing.
Reinstall all previously removed parts in the reverse order. To avoid oil leaks, replace the cylinder head cover gasket.
