TM 5-3895-359-14&P
LUBRICATION SYSTEM
CHAPTER 5
CONTENTS
PAGE
Lubrication System..................................................................................... 10-5-1
Lubricating Oil Pump.................................................................................. 10-5-4
Lubricating Oil Pressure Regulator ........................................................... 10-5-12
Lubricating Oil Filter ................................................................................ 10-5-14
Lubricating Oil Cooler .............................................................................. 10-5-16
Oil Level Dipstick ..................................................................................... 10-5-20
Oil Pan..................................................................................................... 10-5-21
Ventilating System ................................................................................... 10-5-22
Shop Notes - Specifications - Service Tools ............................................. 10-5-23
LUBRICATION SYSTEM
Stabilized oil pressure is maintained within the engine at
typical In-line 71 lubricating system including the various
all speeds, regardless of the oil temperature, by means
components such as the oil pump, oil cooler, bypass
of a regulator valve located between the pump outlet
and full-flow filters, the pressure regulator valve and
and the inlet to the cylinder block. When the oil
bypass valve.
pressure at the valve exceeds 50 psi (345 kPa), the
regulator valve opens 'and remains open until the
The lubricating oil is circulated by a gear-type pressure
pressure is less than the opening pressure.
pump mounted on the No. I and No. 2 main bearing
caps and gear driven from the crankshaft.
Oil Distribution
All the oil leaving the pump is forced through the full-
flow oil filter to the cooler and then into the oil gallery in
Oil from the cooler is conducted by a vertical passage to
the cylinder block from where it is distributed to the
a longitudinal main oil gallery on the blower side of the
various engine bearings. The drain from the cylinder
cylinder block. As shown in Fig. I, this gallery
head and other engine parts leads back to the oil pan.
distributes the oil, under pressure, to the main bearings
and to a horizontal, transverse passage at each end of
A spring-loaded integral plunger-type relief valve,
the cylinder block. From each of these two horizontal
located in the oil pump body, bypasses excess oil from
passages, oil flows through two vertical bores (one at
the discharge to the intake side of the pump when the
each end of the cylinder block) to the end bearings of
pressure in the engine oil gallery exceeds approximately
the camshaft and balance shaft. In addition, oil is
105 psi (724 kPa).
forced through an oil passage in the camshaft which
lubricates the camshaft intermediate bearings. Oil for
If the oil cooler should become clogged, the oil will flow
lubricating the connecting rod bearings, piston pins and
from the pump through a spring-loaded bypass valve
for cooling the piston head is provided through the
directly into the oil gallery.
drilled crankshaft from the adjacent forward main
bearings. The gear train is lubricated by the overflow of
Clean engine oil is assured at all times by the use of a
oil from the camshaft pocket through a communicating
replaceable element type full-flow oil filter incorporated
passage into the flywheel housing. Some oil spills into
in the engine lubrication system. With this type filter,
the flywheel housing from the bearings of the camshaft,
which is installed in the lubricating system between the
balancer shaft and idler gear.
pump and the cooler, all of the oil is filtered before
entering the engine.
10-5-1
