Camshaft drive chain (VAZ-2121)

Wash the chain in kerosene and then check the condition of its links. No chips, cracks or other damage are allowed on the rollers and cheeks. When the engine is running, the chain stretches. It is considered to be operational if the tensioner provides tension, i.e. if the chain has stretched no more than 4 mm.

Check the chain stretch using device 67.7824.9521 (Fig. 2-58), which has two stepped rollers 1, onto which the chain is placed. Using counterweight 3, the chain is stretched with a force of 294 N (30 kgf) or 147 N (15 kgf). Adjusting nut 2 ensures that the counterweight axis is parallel to the base of the device.



Stretch the chain with a force of 294 N (30 kgf), placing the counterweight in the extreme right position, then reduce the force by 147 N (15 kgf), moving the counterweight to the extreme left position. Repeat both operations once more and determine the chain stretch by the distance L (Fig. 2-59) between the roller axes. By measuring the distance between the roller diameters d with a caliper and adding the diameter d to it, you get the distance L between the roller axes.



The article is taken from an online resource (VAZbook.ru)

For a new chain, the distance L between the roller axes is 495.3^+0,5_+0,1 mm; if the chain has stretched to 499.5 mm, it should be replaced. Before installing it on the engine, lubricate the chain with engine oil.