Section 15.10 Defective Crankshaft Main Bearing Shells

Section 15.10
Defective Crankshaft Main Bearing Shells

To determine if defective crankshaft main bearing shells are causing low oil pressure, check main bearing to crankshaft journal clearances.‪

1. If main bearing shell-to-journal clearance is within 0.051-0.127 mm (0.002-0.005 in.), check for defective oil pump assembly; refer to "15.11 Defective Oil Pump Assembly" .
2. If main bearing shell-to-journal clearance is not within 0.051-0.127 mm (0.002-0.005 in.), refer to "15.10.1 Crankshaft Main Bearing Shell Repair" .

Section 15.10.1
Crankshaft Main Bearing Shell Repair

Perform the following steps to repair crankshaft main bearing shells:‪

1. Remove and replace defective crankshaft main bearing shells.
2. Verify crankshaft main bearing shells repair; refer to "15.10.1.1 Test Engine with New Crankshaft Main Bearing Shells" .

Section 15.10.1.1
Test Engine with New Crankshaft Main Bearing Shells

Perform the following steps to determine if new crankshaft main bearing shells have resolved low oil pressure:‪

PERSONAL INJURY ‪
To avoid injury before starting and running the engine, ensure the vehicle is parked on a level surface, parking brake is set, and the wheels are blocked.‪

1. Start and run engine at rated speed.
2. Visually examine the oil pressure reading.
   1. If the oil pressure at rated speed is 241 kPa (35 psi) or more, no further troubleshooting is required. Shut down the engine.
   2. If the oil pressure at rated speed is less than 241 kPa (35 psi), shut down the engine. Check the oil pump assembly; refer to "15.11 Defective Oil Pump Assembly" .