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Home >> Chevrolet >> 2000 >> Astro Van Passenger, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 1189 (Engine Mechanical (Repair Instructions 3 Of 5) - 3.6L (Ly7)) >> Repair Instructions (Off-Vehicle Repair Instructions - Part 2) >> Crankshaft and Bearings Cleaning and Inspection >> Measurement Procedure

Measurement Procedure

WARNING: This page is about a different car, the 2004 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.
    Fig 1: View Of Crankshaft In Fixture
    GM1210780Courtesy of GENERAL MOTORS CORP.
  1. Using a suitable fixture, support the crankshaft.
    2. Fig 2: Identifying J 7872
    GM1210784Courtesy of GENERAL MOTORS CORP.
  2. Install the J 7872  .
  3. Measure the crankshaft runout using the J 7872  . Refer to Engine Mechanical Specifications .
    4. Fig 3: Measuring Crankshaft Thrust Wall Width For Wear
    GM1210786Courtesy of GENERAL MOTORS CORP.
  4. Measure the crankshaft thrust wall width (1) for wear using an inside micrometer. Refer to Engine Mechanical Specifications .
  5. Measure the crankshaft thrust wall surface (2) for runout using the J 7872  . Refer to Engine Mechanical Specifications .
  6. 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.
    7. Fig 4: Inspecting Crankshaft Main Journals For Undersize
    GM1316462Courtesy of GENERAL MOTORS CORP.
  7. Inspect the crankshaft main journals for undersize, using an outside micrometer.
    8. Fig 5: Using An Outside Micrometer To Inspect Crankpins For Undersize
    GM1210787Courtesy of GENERAL MOTORS CORP.
  8. Inspect the crankpins for undersize using an outside micrometer.
  9. Compare your measurements with those listed in the Engine Mechanical Specifications . If the crankpin journals are worn beyond the specifications, the crankshaft may be ground 0.25 mm (0.010 in). There is only 1 size of oversized connecting rod bearings available for service.
    10. Fig 6: Identifying Out-Of-Round Measurements
    GM53224Courtesy of GENERAL MOTORS CORP.
  10. Measure the main bearing and crankpin journals for out-of-round using the following procedure:
    1. Using an outside micrometer, measure the journal at the extreme front and rear locations on the journal. Call these points A and B.
    2. Measure the journal in 2 new locations exactly 90 degrees from the first points. Call these points C and D.
    3. Subtract A from C and B from D. The differences will indicate journal out-of-round.
    4. The out-of-round should not exceed 0.004 mm (0.00016 in) maximum.
    5. 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.
  11. Measure the main bearing and crankpin journals for taper using the following procedure:
    1. Using an outside micrometer, measure the journal at the extreme front (A) and rear (B) of the journal parallel to the crankshaft centerline.
    2. Subtract the smallest from the largest measurement. The result will be the journal taper.
    3. If the main bearing journal taper exceeds 0.004 mm (0.00016 in), replace the crankshaft.
    4. 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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