SERVICE MANUAL
LUBRICATING OIL PUMP, OIL FILTERS & COOLER
Section 8
GENERAL
The lube oil system is unique in that with the exception of
the injection pump and Turbocharger oil supply (1 5, Fig.
1), there Is NO EXTERNAL PIPING to direct oil from one
component to the next. The system is a full- flow type
with a by-pass valve.
The lubrication system supplies filtered lubricating oil at
optimum temperatures throughout the engine to reduce
friction, minimize wear and operate engine controls. Oil
pressure is used to end starting fuel delivery when the
engine starts, and is an actuating force in the injection
pump advance unit. Lubricating oil transfers heat from
the turbocharger, piston sleeves, valves and other
components to the cooling system and surrounding air.
Because the lubricating oil contacts most moving parts in
the engine, keeping the lubricating oil free of abrasive
materials is necessary to obtain long engine life.
Lubricating Oil Pump:
The pump (4, Fig. 1) is a "GEROTOR" type mounted on
and driven directly by the crankshaft (7) at engine speed.
Oil from the sump in the oil pan flows through a tube (8)
and to the front cover opening (3, Fig. 2) where it enters
the pump.
Figure 2. - Lube 011 Passage Locations in Front Cover
& Crankcase
1. Lower oil gallery
2. Pressure outlet
3. Front cover opening
After passing through the pump, the oil re- enters the
cover and is channeled through the pressure outlet (2,
Fig. 2) of the cover Into the forward end of the lower oil
gallery (1, Fig. 2) of the crankcase.
Leaving the gallery, the oil passes through the externally
mounted oil cooler (6, Fig. 1). Upon leaving the cooler,
the oil re-enters the crankcase passage and flows past
the main regulator valve assembly (10, Fig. 1). The oil,
under regulated pressure, again leaves the crankcase,
and through two passageways, enters the externally
mounted filter base (11).
Depending upon the immediate conditions, the oil can
continue on in one of two directions, or in some
instances, divide and travel in both. During normal
operation, the flow of oil continues on through both filter
elements (14, Fig. 1) on its way back into the crankcase
main oil gallery. However, if the filters are not changed
as per Operator’s Manual recommendations, excessive
filter contamination and pressure drop will result. When
such conditions occur, the pressure differential type of
by-pass valve will open allowing the oil to by- pass the
filters and flow directly into the crankcase main oil gallery
where it Is distributed to all parts of the engine. Oil fed to
the main bearings also reaches the connecting rod
bearings and the piston cooling jets (5, Fig. 1). The
same drilled holes that feed oil down to the mains direct
oil up to the camshaft bushings. The annulus cut in the
rear camshaft bearing allows some of the oil fed to
continue up to the rear valve lever shaft bracket (16, Fig.
1) where it is transferred to the hollow shaft (1, Fig. 16)
and distributed to all valve levers. Push rod ball sockets,
tap- pets, valve stems, cam on the camshaft and the
gears are all SPLASH-LUBRICATED.
The "GEROTOR" pump draws oil from the pan through a
stationary pickup tube .(1, Fig. 3) bolted to the crankcase
front cover (2, Fig. 3).
CGES-185-3
PRINTED IN UNITED STATES OF AMERICA
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