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Home >> Chevrolet >> 2021 >> Blazer RS, FWD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 2 (Engine Mechanical - 2.5L (LCV)) >> Repair Instructions >> Crankshaft and Bearing Removal

Crankshaft and Bearing Removal

WARNING: This page is about a different variant/trim than selected.

Crankshaft End Play Measurement

  1. Place a dial indicator at the crankshaft nose.
  2. Gently force the crankshaft to the extreme front and rear positions with a pry tool while monitoring the movement of the dial indicator.
  3. The crankshaft end play should not exceed specifications. Refer to Engine Mechanical Specifications .
  4. If the specifications are exceeded inspect the thrust bearing and the crankshaft thrust wall for wear. Refer to Engine Mechanical Specifications .
  5. Replace the thrust bearing or crankshaft as necessary.

Crankshaft and Bearing Removal

  1. GM2726802Courtesy of GENERAL MOTORS COMPANY

    Remove the crankshaft (1) from the block.

  2. Remove the crankshaft rear oil seal (2) from the block and discard.
  3. GM2742527Courtesy of GENERAL MOTORS COMPANY
    NOTE:

    Crankshaft bearings MUST be separated, marked, or organized in a way to ensure installation to their original location and position, when suitable for use.

    Remove the crankshaft upper bearings (1) and the crankshaft upper thrust bearing (2) from the block.

  4. GM2742531Courtesy of GENERAL MOTORS COMPANY

    Remove the crankshaft lower bearings (2) from the lower crankcase (1).

  5. Clean the oil, sludge, and carbon.
  6. Inspect the oil passages for obstructions.
  7. Inspect the threads.
  8. Inspect the bearing journals and the thrust surfaces for the following conditions:
    • Cracks
    • Chips
    • Gouges
    • Roughness
    • Grooves
    • Overheating (discoloration)
  9. Inspect the corresponding bearing inserts for imbedded foreign material. If foreign material exists find the cause and repair it.
  10. NOTE:

    Replace the crankshaft if cracks, severe gouges or burned spots are found. Slight roughness may be removed with a fine polishing cloth soaked in clean engine oil. Burrs may be removed with a fine oil stone.

  11. Measure the crankshaft journals. Use a micrometer or dial indicator to measure the taper and runout. Note the result for the later selection of bearing inserts. If not within limits the crankshaft must be replaced.

    Note the location of the main bearing high spots. If they are not in line, the crankshaft is bent and must be replaced.