Crankshaft And Main Bearings - Dodge D250 1990 Service Manual

Out-of-Chassis Diagnostic Procedures
Page9H-4
Base Engine Components
DODGE Engine Components
Crankshaft and Main Bearings
Improper maintenance of the lubrication system is the primary
cause of reduced main bearing life.
A malfunction of the crankshaft main bearing will usually be
detected by reduced oil pressure. As with rod bearings,
continued operation with low oil pressure will lead to a rapid
deterioration of the bearings and eventually will produce a
knocking sound.
A damaged or worn thrust bearing flange of the upper main
bearing shell can be detected by measuring the end play of the
crankshaft.