Crankshaft and Bearing Cleaning and Inspection
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Crankshaft and Bearing Cleaning and Inspection
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1.
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Clean the following components in solvent:
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Connecting rod bearings
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Crankshaft oil passages
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Crankshaft threaded holes
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Connecting rod bearings
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Crankshaft oil passages
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Crankshaft threaded holes
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1.
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Perform the following visual inspections:
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Inspect the crankshaft balancer bolt hole (1) for thread damage.
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Inspect the crankshaft balancer mounting area (2) for damage.
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Inspect the crankshaft keyway (3) for damage.
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Inspect the oil pump drive flats (4) for damage.
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Inspect the crankshaft main journals (5) for damage.
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Inspect the crankshaft connecting rod journals (6) for damage.
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Inspect the crankshaft oil passages (7) for obstructions.
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Inspect the crankshaft main bearing thrust wall surfaces (8) for damage.
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Inspect the crankshaft counterweights (9) for damage.
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Inspect the crankshaft reluctor ring teeth (10) for damage.
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Inspect the crankshaft rear main oil seal surface (11) for damage.
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Inspect the crankshaft engine flywheel mounting surface (12) for damage.
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Inspect the crankshaft pilot hole (13) for damage.
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Inspect the crankshaft engine flywheel bolt holes (14) for thread damage.
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2.
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Repair or replace the crankshaft as necessary.
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Crankshaft Bearing Inspection
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1.
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Note
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All connecting rod and main journal bearings that have been used in a running engine must be replaced. Never re-use the crankshaft or connecting rod bearings.
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The following bearing wear conditions should be used to diagnose engine operating conditions or root cause of a condition.
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Inspect for fatigue indicated by craters or pockets. Flattened sections on the bearing halves also indicate fatigue.
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2.
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Inspect for excessive scoring or discoloration on both front and back of the bearing halves.
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3.
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Inspect the main bearings for dirt embedded into the bearing material.
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4.
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Inspect for improper seating indicated by bright, polished sections.
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Special Tools
GE 7872
Magnetic Base Dial Indicator
For equivalent regional tools, refer to
Special Tools
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1.
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Using a suitable fixture, support the crankshaft.
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2.
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Install the
GE 7872
indicator .
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6.
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If the crankshaft journals are damaged or worn beyond specifications, the crankshaft may be ground 0.25 mm (0.010 in). There is only 1 size of oversized main bearings available for service.
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7.
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Inspect the crankshaft main journals for undersize, using an outside micrometer.
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8.
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Inspect the crankpins for undersize using an outside micrometer.
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10.
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Measure the main bearing and crankpin journals for out-of-round using the following procedure:
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10.1.
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Using an outside micrometer, measure the journal at the extreme front and rear locations on the journal. Call these points A and B.
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10.2.
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Measure the journal in 2 new locations exactly 90 degrees from the first points. Call these points C and D.
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10.3.
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Subtract A from C and B from D. The differences will indicate journal out-of-round.
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10.4.
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The out-of-round should not exceed 0.004 mm (0.00016 in) maximum.
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10.5.
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If the journals are worn beyond the specifications, the crankshaft may be ground 0.25 mm (0.010 in). There is only 1 size of oversized crankshaft and connecting rod bearings available for service.
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11.
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Measure the main bearing and crankpin journals for taper using the following procedure:
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11.1.
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Using an outside micrometer, measure the journal at the extreme front (A) and rear (B) of the journal parallel to the crankshaft centerline.
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11.2.
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Subtract the smallest from the largest measurement. The result will be the journal taper.
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11.3.
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If the main bearing journal taper exceeds 0.004 mm (0.00016 in), replace the crankshaft.
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11.4.
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If the journals are worn beyond the specifications, the crankshaft may be ground 0.25 mm (0.010 in). There is only 1 size of oversized crankshaft and connecting rod bearings available for service.
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