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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 429 (Engine Mechanical - 1.8L (LNK)) >> Repair Instructions >> Off-Vehicle Repair Instructions >> Crankshaft and Bearings Cleaning and Inspection (Crankshaft and Bearing Inspect) >> Crankshaft Cleaning and Inspection

Crankshaft Cleaning and Inspection

WARNING: This page is about a different car, the 2003 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.

Important:  Use care when handling the crankshaft. Avoid damage to the bearing surfaces.

    Fig 1: View Of Crankshaft
    G01546498Courtesy of GENERAL MOTORS CORP.
  1. Clean the crankshaft with solvent.
  2. Thoroughly clean all oil passages and inspect for restrictions or burrs.
    CAUTION: Refer to SAFETY GLASSES CAUTION .
  3. Dry the crankshaft with compressed air.
  4. Perform a visual inspection of the crankshaft for damage.
  5. Inspect the crankshaft journals for wear (1).

    Journals should be smooth with no signs of scoring, wear, or damage.

  6. Inspect the crankshaft journals for grooves or scoring (2).
  7. Inspect the crankshaft journals for scratches or wear (3).
  8. Inspect the crankshaft journals for pitting or imbedded bearing material (4).
  9. Measure the crankshaft journals for out-of-round.
    Fig 2: Inspecting Crankshaft Journals
    G01546499Courtesy of GENERAL MOTORS CORP.
  10. Measure the crankshaft journals for taper.
    Fig 3: Measuring Crankshaft Journals
    G01546500Courtesy of GENERAL MOTORS CORP.
  11. Measure the crankshaft runout.

    Using wooden V blocks, support the crankshaft on the front and rear journals.

  12. Use the J 7872  in order to measure the crankshaft runout at the front and rear intermediate journals.
  13. Use the J 7872  in order to measure the runout of the crankshaft rear flange.
  14. Replace or repair the crankshaft if the measurements are not within specifications.
    Fig 4: Measuring Crankshaft Runout
    G01546501Courtesy of GENERAL MOTORS CORP.
  15. Inspect crankshaft bearings for craters or pockets. Flattened sections on the bearing halves also indicate fatigue.
    Fig 5: Inspecting Crankshaft Bearings For Craters, Pockets & Fatigue
    G01546502Courtesy of GENERAL MOTORS CORP.
  16. Inspect the crankshaft bearings for excessive scoring or discoloration.
  17. Inspect the crankshaft bearings for dirt or debris imbedded into the bearing material.
    Fig 6: Inspecting Crankshaft Bearings For Excessive Scoring, Discoloration, Dirt & Debris
    G01546503Courtesy of GENERAL MOTORS CORP.
  18. 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.

Fig 7: Inspecting Crankshaft Bearings For Improper Seating
G01546504Courtesy of GENERAL MOTORS CORP.