Crankshaft and Bearings Installation

Tool Required 

J 36660-A  Torque Angle Meter

Important:  The upper main bearings have an oil groove and oil holes, the lower bearings do not have oil grooves or oil holes.

1. Install the upper main bearings into the cylinder block and lubricate with engine oil.
   Fig 1: Installing Upper Main Bearings

   Courtesy of GENERAL MOTORS CORP.
2. Install the lower main bearings into the lower crankcase and lubricate with engine oil.
   Fig 2: Installing Lower Main Bearings

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3. Install the 2 upper thrust bearing washers into the cylinder block and lubricate with engine oil.

   Important:  Install the upper thrust bearing washers with the oil groove facing outward.

4. Carefully place the crankshaft on to the main bearings in the cylinder block.
   Fig 3: Installing Upper Thrust Bearing Washers

   Courtesy of GENERAL MOTORS CORP.
5. Thoroughly clean and remove any oil residue from the cylinder block mating surfaces.

   Important:  Try to avoid applying an excessive amount of sealant to the surface.

6. Apply a continuous bead of GM P/N 12346240 (Canadian P/N 10953493) or equivalent sealant to the cylinder block mating rails.
   Fig 4: Applying Sealant

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   NOTE: In order to prevent the possibility of cylinder block or crankshaft bearing cap damage, the crankshaft bearing caps are tapped into the cylinder block cavity using a brass, lead, or a leather mallet before the attaching bolts are installed. Do not use attaching bolts to pull the crankshaft bearing caps into the seats. Failure to use this process may damage a cylinder block or a bearing cap.
7. Carefully place the lower crankcase assembly on to the cylinder block.
8. Gently tap the lower crankcase into place with a suitable tool.
   NOTE: This bolt is designed to permanently stretch when tightened. The correct part number fastener must be used to replace this type of fastener. Do not use a bolt that is stronger in this application. If the correct bolt is not used, the parts will not be tightened correctly. The system or the components may be damaged.
9. Install the 10 main bearing cap bolts. Finger tighten.
   Fig 5: Tapping Lower Crankshaft Into Place

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   NOTE: Refer to FASTENER NOTICE .
10. Progressively torque the main bearing cap bolts using 3 steps in the sequence shown.
    Fig 6: Identifying Main Bearing Cap Bolts Tightening Sequence

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    1. 10.1. 1st Pass 

       Tighten the main bearing cap bolts to 22 N.m (16 Ib. ft).

    2. 10.2. 2nd Pass 

       Tighten the main bearing cap bolts to 44 N.m (32 Ib. ft).

    3. 10.3. 3rd Pass 

       After reaching the torque of 44 N.m (32 Ib. ft). Use a J 36660-A  and tighten the main bearing cap bolts an additional 90 degrees.

11. Install the 10 lower crankcase bolts.

    Tighten 

    Tighten the 10 lower crankcase bolts to 18 N.m (13 Ib. ft).