The drive of the gas distribution mechanism of the VAZ-2123 engine consists of sprockets, a chain, a shoe, a damper and a hydraulic chain tensioner.

The engine chain is single-link, unlike the engines of previous models.

If, with a good tensioner and its shoe, as well as with unworn drive sprockets, it is not possible to restore the tension of the chain, then the chain has stretched excessively and must be replaced.

When the chain tensioner shoe is worn, the tensioner response range becomes insufficient to restore chain tension.

In this case, replace the shoe.

The damper is located inside the front of the block head on the left and is attached to it from the outside with two bolts.

If the damper is worn or damaged, under certain engine operating conditions, resonant vibrations of the leading branch of the chain can occur, which can lead to chain jumping on the teeth of the camshaft sprocket and serious engine damage.

Of course, if the chain is stretched and you need to change it, then it is advisable to replace all drive parts.

Removing the timing chain and sprockets and oil pump

Remove the cylinder head cover.

Turn the crankshaft until the mark (hole) on the camshaft sprocket matches the mark on the camshaft bearing housing.

Remove the crankshaft pulley.

Disconnect the camshaft sprocket with the chain from the camshaft.

Remove the chain from the sprocket.

Operations for removing the chain are shown on the engine dismantled from the car.

Removal and fault finding of timing drive parts for VAZ-2123 engine

We unscrew the three bolts securing the oil pan to the camshaft drive cover

Removal and fault finding of timing drive parts for VAZ-2123 engine

Remove the bracket assembly with the roller

Removal and fault finding of timing drive parts for VAZ-2123 engine

Remove the support roller mounting bolt and remove it

Removal and fault finding of timing drive parts for VAZ-2123 engine

We unscrew the bolt securing the plate to the generator mounting bracket

Removal and fault finding of timing drive parts for VAZ-2123 engine

Use a 10 key to unscrew the upper bolt of the plate

Removal and fault finding of timing drive parts for VAZ-2123 engine

Remove the crankshaft position sensor wire holder bracket

Removal and fault finding of timing drive parts for VAZ-2123 engine

Use a 10 key to unscrew the lower plate mounting bolt

Removal and fault finding of timing drive parts for VAZ-2123 engine

Remove the plate

Removal and fault finding of timing drive parts for VAZ-2123 engine

With a 10 key, we unscrew five bolts and two nuts securing the timing cover to the block

Removal and fault finding of timing drive parts for VAZ-2123 engine

Pry off the cover with a screwdriver

Removal and fault finding of timing drive parts of VAZ-2123 engine

Remove the cover

Removal and fault finding of timing drive parts for VAZ-2123 engine

Remove the cover gasket

Removal and fault finding of timing drive parts for VAZ-2123 engine

With a head of 17, turn off the axle of the chain tensioner shoe

Removal and fault finding of timing drive parts for VAZ-2123 engine

Removing the chain shoe

Removal and fault finding of timing drive parts for VAZ-2123 engine

Pull out the timing chain

Removal and fault finding of timing drive parts for VAZ-2123 engine

Remove the sprocket from the front of the crankshaft

Removal and fault finding of timing drive parts for VAZ-2123 engine

If the sprocket is tight, then press it with a puller

Removal and fault finding of timing drive parts for VAZ-2123 engine

Knock the sprocket locking key out of the groove with a beard

Removal and fault finding of timing drive parts for VAZ-2123 engine

Remove the key

Removal and fault finding of timing drive parts for VAZ-2123 engine

We bend the lock washer from the head of the oil pump drive sprocket bolt

Removal and fault finding of timing drive parts of VAZ-2123 engine

Holding the sprocket from turning, unscrew the sprocket mounting bolt with a 17 head

Removal and fault finding of timing drive parts for VAZ-2123 engine

Remove the bolt with washers

Removal and fault finding of timing drive parts of VAZ-2123 engine

Remove the star from the roller

After defect detection, we install all parts in reverse order.

Removal and fault finding of timing drive parts for VAZ-2123 engine

If the crankshaft sprocket is tight, then. wrapping the pulley fastening nut, press it onto the crankshaft shaft.

Removal and defect detection of engine timing drive partsi VAZ-2123

After we press with suitable heads

Removal and fault finding of timing drive parts for VAZ-2123 engine

Before installing the chain, we combine the marks on the sprockets of the crankshaft and camshaft

Timing chain and oil pump failure

Rinse the chain in kerosene and then check the condition of its links.

On rollers and cheeks, chips, cracks and other damage are not allowed.

When the engine is running, the parts of the chain wear out, so the chain is stretched.

It is considered operational as long as the tensioner provides its tension, i.e. if the chain elongation does not exceed 4 mm.

67.7824.9521 tool for checking chain wear (extension): 1 - roller, 2 - adjusting nut, 3 - counterweight

We determine the length of the chain using tool 67.7824.9521

Adaptation 67.7824.9521 has two stepped measuring rollers 1, on which the chain is installed when measuring its length.

One of the rollers is fixed in the fixture body, and the second can move under the action of the measuring force P.

With the help of counterweight 3 (see figure 1), the chain is stretched with a force of 294 N (30 kgf) or 147 N (15 kgf).

Adjusting nut 2 ensures that the axis of the counterweight is parallel to the base of the fixture.

The length of the chain is determined by the center distance L of the measuring rollers 1 (see figure 2).

The new chain has a length L of 495.4-495.8 mm. If the chain is 499.8 mm long due to wear, it should be replaced.

Scheme for checking chain wear (extension): 1 - rollers

Chain length measurement scheme

Measure the chain length in the following sequence:

  • - stretch the chain with a force of 294 N (30 kgf) by placing the counterweight 3 (see Figure 1) in the extreme right position, then reduce the force to 147 N (15 kgf) by moving the counterweight to the extreme left position;
  • - repeat both operations again;
  • - having measured the internal distance between the measuring rollers 1 with a caliper and adding the diameter of the roller d to it, you will get the chain length L. (the distance between the axes of the measuring rollers).

Lubricate the chain with engine oil before installing it on the engine.

Removal and troubleshooting of the hydraulic chain tensioner in the article - "Removal and troubleshooting of the hydraulic tensioner chains VAZ-2123»