TM 9-3431-254-14&P
CENTER MAIN BEARING (V-465D)
3/16 Allen wrench, remove the outer lock screw. With
the same wrench, adjust spring tension by means of
Beginning with serial No. 4904657, a shell type cen-
the adjusting screw; turn clockwise to increase gauge
ter main bearing replaces the roller bearing, and lub-
pressure, counter-clockwise to reduce pressure.
rication to the connecting rod bearings is modified as
follows: Oil pressure to the rods is channeled thru
NOTE: With engine running at 1800 R.P.M. and engine
oil hot, adjust oil pressure 40 to 45 P.S.I. Idle engine
the crankshaft by means of an oil line correction to
at 1000 R.P.M., and if oil pressure falls below 15
the center main bearing instead of thru a collet on the
P.S.I., check for irregularities in the oil pump, bear-
crankshaft gear. See Fig- B-7.
ings and oil connections.
AIR CLEANER
After adjustment is made, mount outer lock screw
The oil bath air cleaner, illustrated in Fig. B-8, must
firmly in place. Use a new 3/4 inch expansion plug to
be serviced frequently, depending on the dust condi-
seal off any oil which may by-pass the screw threads.
tions in which the engine is operated.
LOW PRESSURE SYSTEM
Service daily or twice a day if engine is operating in
very dusty conditions. Once each week; in compara-
The upper, or low pressure oil header, supplies oil to
the camshaft bearings, tappets, valve train and gover-
tively clean conditions.
nor-gear train nozzle at 3 to 4 P.S.I., thru a pressure
Remove oil cup from bottom of air cleaner and clean
reducing valve from the main or high pressure oil
thoroughly. Add the same grade of oil as used in the
header. This pressure is not registered on a gauge,
crankcase, to the level line indicated on the oil cap.
but can be checked by connecting a low pressure
Detailed instructions are printed on the air cleaner.
gauge to the 1/8" pipe tap located at the take-off end
Operating the engine under dusty conditions with-
of the engine above the camshaft plug. Operate the
out oil in the air cleaner or with dirty oil, may
engine at 1800 R.P.M. when making this check.
The pressure reducing valve, mounted on the crank-
a few days time, and result in costly repairs.
case in front of No. 2 cylinder beneath the air duct of
Once a year,oftener if conditions are severe, remove
No. 2-4 bank, is pre-set by the manufacturer (not ad-
air cleaner from engine and soak in solvent to clean
justable). If valve becomes faulty it should be re-
out accumulated dirt from element. Caution: DO not
placed with a completely new unit.
clean with gasoline, naptha or benzine.
