TM 55-2840-241-23
Change 23 5-16.1/(5-16.2 blank)
b.
Use of MIL-L-7808 oil is specified for operation
in ambient temperatures below minus 25 F. This oil may
also be used when MIL-L-23699 oil is not available.
5-20. Oil Change Procedure.
Drain and refill the lubrication system after each
a. Drain the oil tank.
b. Remove the magnetic chip detector from the bot-
tom of the gearbox and drain residual oil. (Refer to para-
graph 5-24.)
c. Remove and clean or replace the oil filter. (Refer
to paragraph 5-25.)
d. Refill the oil tank with engine oil (item 7 or 8, table
2-2).
e. Remove and clean the magnetic chip detector on
the forward side of the gearbox (refer to paragraph 5-24).
While both magnetic plugs are removed, motor the en-
gine with the starter and permit a small amount of oil (1
or 2 ounces) to flow from the openings in the gearbox.
This will assist in rinsing the gearbox of carbon particles.
Reinstall the cleaned magnetic plugs.
f. Refer to figure 5-10.1. Loosen clamp nut, then fit-
tings and remove the line going to the ºTº fittings that
feeds oil to the number six and seven bearing. Pressure
Oil Tube 6871470. Remove the small oil screen,
6840476 (Pressure Oil Fittings Screen Assembly). Motor
the engine with the starter and permit a small amount of
oil (1 or 2 ounces) to come out the end of the oil tube.
Clean and reinstall the screen and tube assembly. Tight-
en pressure oil tube coupling nuts to the applicable
torgue identified in table 5-1.2. Tighten clamp nuts
g. Motor the engine with the starter until positive oil
pressure indication is obtained. Do not exceed starter
limitations.
h. After all work is completed make a ground run,
check for leaks and monitor oil pressure for the first five
minutes of engine operation. Check and reservice the oil
tank to the proper level.
i. To prime the pumps, perform the following steps:
(1)
Disconnect the engine oil pump inlet hose
assembly from the elbow fitting.
(2)
Loosen the elbow locknut and rotate the el-
bow to an upright position.
(3)
Fill the elbow to spillover with engine oil.
(4)
Fill engine inlet hose with engine oil.
(5)
Reposition elbow and connect the engine oil
pump inlet hose assembly and tighten appropriate com-
ponents.
5-21. Oil Changeover Procedure.
When changing over from MIL-L-7808 oil to
MIL-L-23699 oil or vice versa, proceed as follows:
a. Drain the oil tank, system components and piping,
and engine gearbox as completely as possible.
b. Remove and clean or replace the oil filter. (Refer
to paragraph 5-25.)
c. Remove, inspect, and clean the magnetic chip de-
tectors.
d. Fill the oil tank with the desired lubricating oil (item
7 or 8, table 2-2) .
e. Motor the engine to pump oil through the system.
Check the tank oil level and add oil as required. Repeat
the motoring cycle until the tank oil level does not
change.
f. Run the engine for 30 minutes to one hour and shut
down.
g. Inspect and clean or replace the oil filter.
(1)
If the filter was heavily contaminated, accom-
plish steps h through l.
to 35 to 40 in. lb.
300 hours of engine operations as follows:
