To determine if defective crankshaft main bearing shells are causing low oil pressure, perform
the following steps:
1.Check main bearing to crankshaft journal clearances; refer to appropriate service manual, engine chapter.
[a] If main bearing shell-to-journal clearance is within 0.040 – 0.151 mm (0.0016 -0.006 in.), check oil pump assembly; refer to section 2.12.
[b] If main bearing shell-to-journal clearance is not within 0.040 – 0.151 mm (0.0016 -0.006 in.), refer to section 2.11.1.
2.11.1
Crankshaft Main Bearing Shell Repair
Perform the following steps to repair crankshaft main bearing shells:
1. Remove and replace defective crankshaft main bearing shells; refer to appropriate service manual, engine chapter.
2. Verify crankshaft main bearing shells repair: refer to section 2.11.1.1.
2.11.1.1
Test Engine with New Crankshaft Main Bearing Shells
Perform the following steps to determine if repaired relief valve resolved low oil pressure:
1. Connect to DDDL 7.0.
2. Start and run engine between 1800 rpm.
3. Visually examine DDDL 7.0 for oil pressure reading.
[a] If DDDL 7.0 indicates 241 kPa (35 psi), at 1800 rpm, shut down the engine and
disconnect DDDL 7.0. No further troubleshooting is required.
[b] If DDDL 7.0 indicates less than 241 kPa (35 psi) at 1800 rpm, shut down the engine
and disconnect DDDL 7.0. Check the oil pump assembly; refer to section 2.11.
