Crankshaft and flywheel
The design of the crankshaft is shown in fig. 4.7.
The crankshaft of the engine is four bearing, cast from spheroidal graphite iron. The supports are made in the body of the crankcase of the cylinder block in the form of plain bearings. Oil grooves are made in the upper shells of the main bearings. Counterweights are made on the cheeks of the shaft, cast together with the shafts. Crankshafts are divided into three size groups, marked with colored colorful marks (yellow, green and white) on the cheeks in the region of the root necks.
Diameter of main journals of crankshafts:
yellow label:
- nominal size - 69.984 - 69.990 mm:
- size 1st class - 69.734 - 69.740 mm;
(reduction by 0.25 mm)
- size 2nd class - 69.484 - 69.490 mm;
(reduction by 0.50 mm)
- size 3rd class - 69.234 - 69.240 mm.
(reduction by 0.75 mm)
green label:
- nominal size - 69.977 - 69.983 mm;
- size 1st class - 69.727 - 69.733 mm;
(reduction by 0.25 mm)
- size 2nd class - 69.477 - 69.483 mm.
(reduction by 0.50 mm)
- size 3rd class - 69.227 - 69.233 mm.
(reduction by 0.75 mm)
white label:
- nominal size - 69.971 - 69.976 mm;
- size 1st class - 69.721 - 69.726 mm;
(reduction by 0.25 mm)
- size 2nd class - 69.471 - 69.476 mm.
(reduction by 0.50 mm)
- size 3rd class - 69.221 - 69.226 mm.
(reduction by 0.75 mm)
Axial clearance of the crankshaft:
- nominal - 0.085 mm;
- maximum - 0.257 mm.
Radial clearance of crankshaft main bearings:
- nominal - 0.020 mm;
- maximum - 0.050 mm.
Diameter of connecting rod journals of the crankshaft:
- nominal size - 48.00 mm;
- 1st repair size - 47.75 mm;
- 2nd repair size - 47.50 mm;
- 3rd repair size - 47.25 mm.
with execution tolerance from -0.009 to -0.025 mm.
Radial clearance of connecting rod bearings:
- nominal - 0.016 mm;
- maximum - 0.055 mm.
The maximum allowable ovality of the surfaces of the main and connecting rod journals is not more than 0.003 mm.
Crankshaft bearing shells
Inserts of main and connecting rod bearings bimetallic three-layer.
Radial clearance between bearing shells and crankshaft main/conrod journals:
- nominal - 0.016 / 0.016 mm;
- maximum allowable - 0.055 / 0.055 mm.
Permissible runout of the crankshaft, measured on the middle neck, no more than 0.15 mm.
Thrust Bearing Width:
- nominal - 32.0 mm;
- 1st repair size - 32.2 mm;
- 2nd repair size - 32.4 mm;
- 3rd repair size - 32.6 mm;
execution tolerance from +0.050 to +0.020 mm.
If the gaps are greater than the maximum allowable, this indicates the need to replace the liners (semirings) on the crankshaft journals with new ones. If the crankshaft journals are worn, they are ground to the nearest repair size, and the liners are replaced with repair ones (increased thickness).
Flywheel and Drive Disc
The design of the flywheel and drive plate is identical to the engine «M54», see fig. 3.11.
With the M62 engine, an automatic transmission with a drive disc is used as standard. On request, a manual transmission with a dual-mass flywheel can be installed.
drive disc (with automatic transmission) or dual mass flywheel (with manual transmission), are attached to the crankshaft flange with eight bolts. After removing the bolts of their fastening, replace them with new ones, with a preliminary application of a locking compound to their threaded part.
Bolts of fastening of a drive disk (flywheel) engine model «M62» criss-cross:
- dual-mass flywheel torque - 10.5 kgf·m (105 Nm).
- drive disk torque - 12.0 kgf·m (120 Nm).
Permissible drive disc runout (flywheel) for all engine models, when measured along the outer circumference, not more than 0.20 mm.
Vibration damper
The design of the torsional vibration damper is shown in fig. 4.8.
The vibration damper has a diameter of:
- model engine «М62В44» - 270 mm;
- model engine «М62В46» - 275 mm.
Color of marking, black. Permissible axial runout, no more than 0.30 mm. Permissible ovality, no more than 0.20 mm.
Pistons
The design of the pistons and connecting rods of the cylinder block is shown in fig. 4.9.
The pistons are made of aluminum alloy with steel inserts by «Mahle» (Germany). Each piston has two compression rings and one oil scraper ring. For the correct orientation of the piston, when installed in the cylinder, there is an arrow on its bottom, which must be turned towards the camshaft drive, as well as a mark indicating its diameter. The piston diameter is measured at a distance «A» from the lower edge of the piston skirt at an angle of 90°relative to the axis of the piston pin.
The piston oversize is only valid for a cast aluminum cylinder block with thin-walled gray cast iron liners.
Model engine «М62В44»:
Piston diameter:
- nominal - 91.990 mm;
- intermediate - 92.070 mm;
- 1st repair (+0,25) - 92.240 mm;
- 2nd repair (+0,50) - 92.490 mm.
Estimated clearance between piston and cylinder:
- for new parts - from 0.006 to +0.038 mm;
- maximum allowable - 0.10 mm;
Model engine «М62В46»:
Piston diameter:
- nominal - 92.980 mm;
- intermediate - 92.994 mm;
Estimated clearance between piston and cylinder:
- for new parts - from 0.006 to +0.034 mm;
- maximum allowable - 0.10 mm;
Permissible difference in weight between pistons for one engine is not more than 10 g.
The maximum allowable deviation of the piston diameter from the nominal size should not exceed 0.014 mm.
Measurement of the piston diameter is carried out at a distance from the lower edge of the piston skirt «A», equal to:
- model engine «М62В44» - 12 mm;
- model engine «М62В46» - 21.5 mm.
Piston pins
Piston pin steel, polished, floating type. From axial movement, it is held by two retaining rings in the piston holes for the piston pin. Fingers are made in two classes, marked with color marks - black and white.
The length of the piston pin is 62 mm.
The piston pin diameter for all engine models is 22 mm, with a manufacturing tolerance of -0.003 to -0.006 mm.
Nominal clearance between the piston pin and the piston - 0.00092 - 0.006 mm;
Clearance between piston pin and connecting rod bushing:
- fingers with «white» label - 0.003 - 0.005 mm.
- fingers with «black» label - 0.005 - 0.007 mm.
Permissible operating clearance between the piston pin and the bushing of the upper head of the connecting rod is 0.0092 mm.
When repairing the engine, only pistons and pins of the same configuration should be installed.
Piston rings
Piston rings are installed in the grooves of the piston head: two compression and one oil scraper.
Rings are installed on the piston with a mark «Thor» («Top») to the bottom of the piston (fire belt).
The upper compression ring is chrome-plated, with rounded edges, the lower compression ring is tapered, the oil scraper ring with expander.
Gap between new piston ring and groove wall:
Model engine «М62В44»:
- upper compression - 0.002 - 0.060 mm;
- lower compression - 0.002 - 0.060 mm;
- oil scraper - not measured;
- the maximum allowable size is 0.12 mm.
Model engine «М62В46»:
- upper compression - 0.002 - 0.070 mm;
- lower compression - 0.002 - 0.060 mm;
- oil scraper - 0.020 - 0.060 mm;
- the maximum allowable size is 0.12 mm.
Gap in the lock of the new piston ring:
Model engine «М62В44»:
- upper compression - 0.10 - 0.30 mm;
- lower compression - 0.20 - 0.40 mm;
- oil scraper - 0.20 - 0.90 mm;
Model engine «М62В46»:
- upper compression - 0.10 - 0.30 mm;
- lower compression - 0.20 - 0.40 mm;
- oil scraper - 0.25 - 0.50 mm;
The maximum allowable gap in the lock for all engine models for compression rings is 0.80 mm, for oil scraper rings 1.00 mm.
Connecting rods
The design of the connecting rods is shown in fig. 4.9.
Forged connecting rods with heat-treated steel I-section shank, with thin-walled tri-metal plain bearing shells. A bimetallic, coiled (rolled up) sleeve. According to the diameter of the hole of the lower head, the connecting rods are divided into two size groups, marked with color marks in red and blue.
Connecting rod bore diameter:
- with a red label - 52.000 - 52.006 mm;
- with a blue label - 52.007 - 52.013 mm.
The lower head of the connecting rod undergoes final processing with its cover and is not subject to further dismantling.
Connecting Rod Bushing Diameter:
- outer - 24.060 - 24.100 mm;
- internal - 22.005 - 22.012 mm.
The maximum permissible operating clearance between the connecting rod bearings and the crankshaft journals for all engine models is 0.12 mm.
Permissible difference in weight between connecting rods on the same engine, no more than 3.0 g.
Permissible twisting of the connecting rod for all engine models is no more than 30'.
Tolerance of non-parallelism and misalignment of the axes of the holes over a length of 100 mm, for all engine models, not more than 0.04 mm.
The maximum allowable axial clearance of the connecting rod on the crankshaft journal relative to its web for all engine models is 0.37 mm.