Inspection Procedure

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Fig 1: CKP Reluctor Ring Teeth

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NOTE:

The reluctor ring teeth should not have imperfections on the rising or falling edges. Imperfections of the reluctor ring teeth may affect OBD II system performance.

Inspect the CKP reluctor ring teeth (1) for damage.

Fig 2: Crankshaft Journals

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Inspect the crankshaft journals for wear.
Journals should be smooth (1) with no signs of scoring, wear, or damage.
Inspect the crankshaft journals for grooves or scoring (2).
Inspect the crankshaft journals for scratches or wear (3).
Inspect the crankshaft journals for pitting or imbedded bearing material (4).
Inspect the crankshaft rear oil seal surface (5) for grooves or scoring.

Fig 3: Crankshaft Key, Keyway And Threaded Hole

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Inspect the crankshaft key (122), keyway (1), and threaded hole (2) for damage.

Fig 4: Measuring Connecting Rod Journals For Out-Of-Round And Taper

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Measure the connecting rod journals for out-of-round and taper.

Fig 5: Measuring The Crankshaft Thrust Wall Width

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Measure the crankshaft thrust wall width.
A crankshaft with a thrust wall width in excess of 26.2 mm (1.0315 in) (a) must be replaced.

Fig 6: Measuring Crankshaft Runout

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Measure the crankshaft runout.
Use wooden V-blocks or a fixture to support the crankshaft on the front and rear journals.
Use the J 7872 set in order to measure the crankshaft runout at the front and rear intermediate journals.
Use the J 7872 set in order to measure the runout of the crankshaft rear flange.
Use the J 7872 set in order to measure the runout of the crankshaft position reluctor ring. Reluctor ring runout should be measured 1.0 mm (0.04 in) below the ring teeth.
If the front and rear intermediate journals, crankshaft rear flange, or reluctor ring runout exceeds specification, replace the crankshaft. Refer to Engine Mechanical Specifications (RPO LC9 VIN 3) , Engine Mechanical Specifications (RPO LMG VIN 0) , Engine Mechanical Specifications (RPO L9H) , Engine Mechanical Specifications (RPO L94 VIN F) , Engine Mechanical Specifications (RPO L96 VIN G) .

Fig 7: Inspecting Bearings For Craters Or Pockets

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Inspect crankshaft bearings for craters or pockets. Flattened sections on the bearing halves also indicate fatigue.

Fig 8: Connecting Rod Bearing Scoring Or Discoloration

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Inspect the crankshaft bearings for excessive scoring or discoloration.
Inspect the crankshaft bearings for dirt or debris imbedded into the bearing material.

Fig 9: Inspecting Bearings For Improper Seating

Courtesy of GENERAL MOTORS CORP.

Inspect the crankshaft bearings for improper seating, indicated by bright, polished sections of the bearing.
If the lower half of the bearing is worn or damaged, both upper and lower halves should be replaced.

Generally, if the lower half is suitable for use, the upper half should also be suitable for use.