In the lower part of the cylinder block, between the beds of the main bearings, there are nozzles for cooling the pistons. Loosen the screws securing the oil injectors and remove them (arrow, fig. 4.86).
Before installation, measure the nominal clearance between the piston and the bore in the cylinder block, for which:
- measure the piston diameter with a micrometer «A» from the lower edge of the skirt in a plane at 90°to the axis of the piston pin (pic. 4.87) and offset by 90°in the horizontal plane.
- For «М62В44» piston diameter should be 12.0 mm, and for «М62В46» - 21.5 mm;
- measure the diameter of the cylinder mirror in three planes with a micrometer (top, middle and bottom) and calculate the average value, which should be for «М62В44» within 91.976 - 91.994 mm, for «М62В46» - within 92.980 - 92.000 mm;
- subtract from the value of the average cylinder diameter, the piston diameter;
- the resulting value of the nominal clearance must be for «М62В44» within 0.006 - 0.038 mm, for «М62В46» - within 0.006 - 0.034 mm;
- the maximum allowable value, as a criterion for the necessary repair when parts are worn, is 0.10 mm.
Piston rings are compressed with a tool «11.9.500» for engine «М62В46» or fixture «11.2.260», for engine «М62В44». The clamping band around the entire perimeter must fit snugly against the surface of the piston.
Replace connecting rod bearing shells. Lubricate the connecting rod bearing shells with engine oil. Install the bearing cap so that the pairing numbers match on one side (see fig. 3.98).
Insert new clean connecting rod bolts lightly lubricated with engine oil. Using fixtures «00.9.120» or «11.2.110» (torque wrench with goniometer), tighten both bolts in three parallel steps on each bolt:
- 1st reception, torque 5.0 Nm (0.5 kgf·m);
- 2nd reception, torque 20 Nm (2.0 kgf·m);
- 3rd reception, tighten by an angle of 80°.
Continue assembling the engine in reverse order. If necessary, replace the screws securing the piston cooling nozzles. Coat the threaded part of the bolts with anti-self-loosening agent.