3-169. LUBE OIL PUMP - MAINTENANCE INSTRUCTIONS.
a. The gear-type oil pump is mounted on the first and second main b aring caps and is gear-driven from
the front end of the crankshaft.
b. The oil pump helical gears rotate inside a housing. The drive gear is keyed to the drive shaft which is
supported inside the housing on two bushings with a drive-driven gear keyed to the outer end of the shaft. The
driven gear is supported on the driven gear shaft which is pressed into the pump body.
c. An integral plunger-type relief valve by-passes excess oil to the inlet side of the pump when the pressure
in the oil lines exceeds 105 pounds per square inch (724 kPa).
d. An inlet pipe, attached to the inlet opening in the pump body, leads to the inlet screen which is mounted
with brackets to a main bearing cap.
e. The inlet screen is located below the oil in the pan and serves to strain out any foreign material which
might damage the pump.
f. The oil pump inlet screen should be removed and cleaned periodically in addition to the cleaning it
receives each time the engine is reconditioned.
g. An idler gear is mounted on a support bracket which is attached to the pump body.
h. Pressure lubrication of the idler gear bushing is provided by means of a drilled passage in the pump body
and a connecting passage in the idler gear support bracket.