Checking cylinder diameters
Make accurate measurements of cylinder diameters. Make measurements with a caliper in three belts as in transverse directions «A», and in the longitudinal direction «IN», as shown in the diagram in the section «Four cylinder engine»
In cases where wear exceeds the allowable values by more than 0.08 mm, bore the cylinders to the nearest oversize and install pistons of the appropriate oversize.
Checking clearances between liners and crankshaft journals
Thoroughly clean the running surfaces of the liners and the corresponding crankshaft journal. Place 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 with a torque of 5.0 kgf·m, the bolts of the main bearing caps with 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 0.016-0.075mm (maximum allowable 0.16 mm) for indigenous and 0.015-0.062 mm (maximum allowable 0.12 mm) for crankpins.
If the clearance is greater than the limit, grind the crankshaft journals to the repair size.
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 0.25 mm.
If necessary, achieve proper clearance by placing thicker thrust washers on the fourth leg.
Checking the dimensions of pistons and piston rings
Determine the degree of piston wear by measuring the diameter of 10 mm from the edge of the piston skirt perpendicular to the axis of the piston pin. The piston must be replaced if its diameter differs by more than 0.04 mm from the permissible values (see subsection c «Detailed Specifications».
Replace the piston rings or pistons if the gaps between the piston rings and grooves exceed the allowable values (see subsection «Detailed Specifications»).
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