15 - Engine
45 - Oil Sump
00 - General
15 - 173 9823/0000-1 15 - 173
00 - General
Introduction .................................................. 15-173
Component Identification ............................. 15-174
Remove and Install ..................................... 15-175
Introduction
The lubrication system distributes oil around the
engine by a system of galleries and drillings in the
crankcase and cylinder head. The oil lubricates and
seals the moving parts of the engine, reducing friction
and wear. In addition the oil plays an important role in
cooling the engine by carrying heat from the engine
to the cooler. A piston cooling jet sprays oil onto the
underside of the pistons to keep them cool, refer to
(PIL 15-36).
Oil is drawn from the oil sump by the integral oil pump
via the suction strainer. The strainer prevents any
large particles of debris passing through, which may
damage the pump.
The oil passes from the outlet side of the pump
through a relief valve which limits the maximum oil
pressure by venting oil back to the inlet side of the
pump, refer to (PIL 15-36).
From the pump the oil passes through the oil cooler
and filter, refer to (PIL 15-69 and PIL 15-21).
After cooling and filtering, the oil passes into the
main oil gallery. An oil pressure switch senses the
oil pressure. From the main gallery oil is delivered,
via drillings, to the crankshaft main bearings, rocker
assembly, camshaft and timing gears. Note that
drillings are through the crankcase and cylinder
head.
When the high pressure oil has passed through the
bearings it reverts to sump pressure and splash
lubricates the internal components such as rocker
tips, cam lobes and timing gear teeth. Gravity
drains the oil via drains into the cylinder head and
crankcase, back into the oil sump. A drain slot allows
the oil to drain from the timing case back to the oil
sump.