GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

  1. Remove the engine oil pan and the oil pump strainer from the cylinder block (1). Refer to Oil Pan Replacement .
  2. Start at the front of the engine and service the main bearings one at a time.
  3. Remove the two main bearing cap bolts.
  4. Carefully remove the main bearing cap.
  5. Carefully rotate the crankshaft and remove the upper bearing half.

  6. Object Number: 166744  Size: SH

    Important: Any time the main bearings must be replaced, both the upper and lower halves should be replaced as a set. Never replace only one of the halves.

  7. Inspect the main bearings. Refer to Crankshaft and Bearing Cleaning and Inspection .

Installation Procedure


    Object Number: 166744  Size: SH

    Important: The main bearing upper half has an oil groove, insure the upper bearing is installed correctly.

  1. Install the main bearing upper half (3) with the oil groove to the cylinder block (1).
  2. Lightly oil the bearing surfaces.

  3. Object Number: 166742  Size: SH

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

    Important: Gradual and uniform tightening is important for the main bearing cap bolts.

  4. Remove and service each of the remaining main bearing caps one at a time. Service each of the caps in ascending order of numbers 1, 2, 3, 4 and 5. Start from crankshaft pulley side (2) and continue through to the flywheel side (1). Ensure that all of the arrow marks point toward the crankshaft pulley side.
  5. Tighten
    Tighten the main bearing cap bolts to 54 N·m (40 lb ft).

  6. Install the oil pump strainer and the engine oil pan to the cylinder block. Refer to Oil Pan Replacement .