GM Service Manual Online
For 1990-2009 cars only
  1. Clean the crankshaft bearings and the crankshaft journals with solvent and compressed air.
  2. Inspect each bearing journal and bearing for damage.
  3. Inspect the reluctor ring for any damage to the sensor ring teeth.
  4. Support the crankshaft on wooden v-blocks at the front (1) and rear (5) journals.

  5. Object Number: 35207  Size: SH
  6. Check the crankpins for undersize using an outside micrometer.

  7. Object Number: 53224  Size: SH
  8. Check crankshaft main bearing and crankpin journals for out-of-round using the following procedure:
  9. 6.1. Using an outside micrometer, measure the journal at the extreme front and rear locations on the journal. Call these points A and B.
    6.2. Measure the journal in two new locations exactly 90 degrees from the first points. Call these points C and D.
    6.3. Subtract A from C and B from D. The differences will indicate journal out-of-round.
    6.4. The out-of-round should not exceed 0.004 mm (0.00016 in.) maximum.
    6.5. If the specifications are exceeded, replace the crankshaft.
  10. Measure the crankshaft bearing journals for taper using the following procedure:
  11. 7.1. Using an outside micrometer, measure the journal at the extreme front and rear of the journal parallel to the crankshaft centerline.
    7.2. Subtract the smallest from the largest measurement. The result will be the journal taper.
    7.3. If the crankshaft bearing journal taper exceeds 0.004 mm (0.00016 in), replace the crankshaft.
    7.4. If the crankpin journal taper exceeds 0.005 mm (0.0002 in), replace the crankshaft.
  12. If the crankshaft journals are damaged or worn beyond dimensions, replace the crankshaft. No machining of the crankshaft journals is allowed.