Checking cylinder diameters
Make accurate measurements of cylinder diameters. Measurements to be made with a caliper in three belts as in the transverse direction «A», and in the longitudinal direction «B», as shown in the diagram in the section «EP, YN, WV, YP, DT and DS four-cylinder engines».
In cases where wear exceeds the allowable values by more than 0.04 mm, bore the cylinders to the nearest repair size and install pistons of the corresponding repair size.
Checking clearances between liners and crankshaft journals
Install the crankshaft to the cylinder block.
Thoroughly clean the running surfaces of the liners and the corresponding crankshaft journal. Put a piece of plastic calibrated wire, equal in width to the insert, on the surface of the neck.
Depending on the type of neck to be checked, install a connecting rod with a cap or a main bearing cap on the neck and tighten the fastening nuts or bolts, respectively. Tighten the nuts of the connecting rod bolts first to a torque of 3.0 kgf·m, then tighten by 90°, or the bolts of the main bearing caps to a torque of 6.5 kgf·m. Do not allow the crankshaft of the engine to rotate.
Carefully remove the cover and, using the scale printed on the package, determine the size of the gap by the flattening of the wire. More details are given in the accompanying documentation of the gauge wire manufacturer.
The nominal design gap is 0.030-0.080 mm (maximum allowable 0.17 mm) for indigenous and 0.020-0.076 mm (maximum allowable 0.095 mm) for crankpins.
If the gap is greater than the limit, then replace the liners on these necks with new ones. If the crankshaft journals are worn out and are ground to a repair size, then replace the liners with repair ones (increased thickness).
Checking the axial clearance of the crankshaft
Check the axial clearance of the crankshaft using a feeler gauge on the third bearing, which should be no more than 0.20 mm.
If the clearance is greater than the limit, and the main journals of the crankshaft are not ground, put liners with thrust collars on the third support of the nominal size. If the main journals are ground to the repair size, put liners of the corresponding repair size on the third support.
Checking the dimensions of pistons and piston rings
Determine the degree of wear of the piston by measuring the diameter of 10 mm from the edge of the piston skirt perpendicular to the axis of the piston pin (see photo in section «EP, YN, WV, YP, DT and DS four-cylinder engines». The piston must be replaced if its diameter differs by more than 0.04 mm from the permissible values (see subsection «Design and specifications»).
Replace the piston rings or pistons if the gaps between the piston rings and grooves exceed the allowable values (see subsection «Design and specifications»).
Marking of covers of main bearings of a cranked shaft
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