Crankshaft and Bearings Removal

WARNING: This page is about a different car, the 2003 GMC Sonoma and 2003 Chevrolet S10 Pickup. However, it is still accessible from the selected car via links, so may be relevant.

Remove the main bearing caps and the main bearings. Mark the main bearing caps in order to ensure that they are installed in the same place from which they were removed.

Fig 1: Removing Main Bearing Caps And Main Bearings
Courtesy of GENERAL MOTORS CORP.
Remove the crankshaft.
Clean the crankshaft.
Clean any obstructions from the oil passages on the crankshaft.
Inspect the keyway and the threads in the front of the crankshaft, and the threads in the flywheel bolt holes.
Inspect the bearing journals and the thrust surfaces for the following items:
- Wear
- Cracks
- Chips
  Replace the crankshaft if the crankshaft is chipped.
- Gouges
  Replace the crankshaft if the crankshaft is gouged.
  
  Fig 2: Removing Crankshaft
  Courtesy of GENERAL MOTORS CORP.
- Roughness
- Grooves
- Discoloration due to overheating
  Replace the crankshaft if the crankshaft is discolored.
Use a micrometer in order to measure the crankshaft taper. If the crankshaft taper is not within specifications, replace the crankshaft. Refer to ENGINE MECHANICAL SPECIFICATIONS .
Measure the crankshaft runout. If the crankshaft runout is not within specifications, replace the crankshaft. Refer to ENGINE MECHANICAL SPECIFICATIONS .