Crankshaft Main Bearing: Service and Repair

Removal Procedure

CAUTION: Refer to Battery Disconnect Caution in Service Precautions.

1. Disconnect the negative battery cable.
2. Raise and support the vehicle. Refer to Vehicle Lifting.
3. Place a drain pan or suitable container underneath the engine oil pan.
4. Remove the engine oil drain plug and gasket. Allow the engine oil to drain.





5. Remove the following components from the vehicle:
^ Fourteen bolts
^ Two nuts
^ Crankshaft position sensor
^ The engine oil pan
6. Remove the following components from the vehicle:
^ Eight main bearing bolts
^ Four main bearing caps with lower inserts
7. Remove the four upper inserts from the cylinder block.
8. Inspect the main bearings for pitting, scratches, wear or damage. Replace both of the upper and lower halves of the main bearings if any of these conditions are found. Any time the main bearings must be replaced, both the upper and lower half should be replaced as a set. Do not replace only one of the halves.

Installation Procedure

IMPORTANT: The upper insert has an engine oil groove. Install the insert with the engine oil groove to the cylinder.





1. Install the upper inserts (2) to the cylinder block (1).

NOTICE: Refer to Fastener Notice in Service Precautions.

IMPORTANT: Lightly oil the main bearing cap bolts prior to installation. Gradual and uniform tightening is important for main bearing bolts. After tightening the main bearing cap bolts, inspect in order to check that the crankshaft rolls smoothly when turned by hand.

2. Install the main bearing caps with the lower inserts and secure with the eight main bearing cap bolts. Each main bearing cap is embossed with an arrow mark and a number. When installing each bearing cap to the cylinder block, point the arrow mark toward the crankshaft timing pulley side and in order 1, 2, 3 and 4. Tighten the main bearing caps.
Tighten the main bearing cap bolts to 54 Nm (40 ft. lbs.)
3. Install the oil pump strainer and the oil pump strainer seal to the cylinder block and secure with the oil pump strainer bolt first and then the oil pump strainer bracket bolt.
Tighten the oil pump strainer bolt first and then the oil pump strainer bracket bolt to 11 Nm (8 ft. lbs.).
4. Apply a continuous bead of GM P/N 12346240 or equivalent, to the engine oil pan mating surface.
5. Install the engine oil pan to the cylinder block and secure the engine oil pan with fourteen bolts and two nuts starting at the center and working outward.
Tighten the engine oil pan bolts and nuts to 11 Nm (97 inch lbs.)
6. Install the gasket and the engine oil pan drain plug.
Tighten the engine oil drain plug to 35 Nm (26 ft. lbs.)
7. Install the crankshaft position sensor.
Tighten the crankshaft position sensor bolt to 11 Nm (97 inch lbs.)
8. Lower the vehicle.
9. Fill the engine oil to specifications.
10. Connect the negative battery cable.
11. Inspect coolant system for leaks.
12. Start the engine. Inspect the exhaust system for exhaust leaks.
13. Run the engine in order to inspect the engine oil pressure.