Device Features
Crankshaft steel, forged, five-bearing. with eight counterweights. Main journals diameter, mm:
- nominal: 54.00-0,022-0,042
- 1st repair size: 53.75-0,022-0,042
- 2nd repair size: 53.50-0,022-0,042
- 3rd repair size: 53.25-0,022-0,042
Diameter of connecting rod journals, mm:
- nominal: 47.80-0,022-0,042
- 1st repair size: 47.55-0,022-0,042
- 2nd repair size: 47.30-0,022-0,042
- 3rd repair size: 47.05-0,022-0,042
The maximum allowable ovality of the surfaces of the main and connecting rod journals is not more than 0.003 mm.
The nominal axial clearance of the crankshaft when measured on the middle support is 0.07-0.17 mm. maximum allowable 0.25 mm.
The gap between the liners and the main journals of the crankshaft: nominal 0.03-0.08 mm; maximum permissible in operation 0.17 mm.
The flywheel is attached to the crankshaft flange with six bolts.
Permissible runout of the flywheel when measured along the circumference of the surface under the clutch disc, no more than 0.08 mm. On cars from the 1991 model year, after removing the flywheel, the bolts of its fastening must be replaced with new ones with a preliminary application of a locking compound to their threads.
Bolts are wrapped in two steps:
- 1st: moment 6 kgf·m;
- 2nd: turn 905.
Checking the technical condition
Check the condition of the connecting rod and main journals. If they have scratches and their dimensions do not correspond to the above values, it is necessary to regrind them, taking into account the repair dimensions. No adjustments can be made on the inserts. If there are scuffs, scratches or delaminations, replace the liners with new ones.
Checking clearances between liners and crankshaft journals
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. Nuts of connecting rod bolts must first be tightened with a torque of 3.0 kgf·m. and then tighten by 180°, 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 0.030-0.080 mm (maximum allowable 0.170 mm) for indigenous and 0.015-0.062 mm (maximum allowable 0.12 mm) for crankpins.
If the gaps are greater than the limit, then replace the liners on these necks with new ones. If the crankshaft journals are worn out, but are ground to a repair size, then replace the liners with repair ones (increased thickness).
Checking the axial clearance of the crankshaft
The clearance is checked on the middle bearing of the crankshaft using a feeler gauge, which should be no more than 0.25 mm. If necessary, achieve proper clearance by using thicker thrust washers.
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