LO-9-2320-279-12
M977 SERIES, 8X8 HEAVY EXPANDED MOBILITY TACTICAL TRUCKS (HEMTT)
LUBRICATION ORDER
DECEMBER 1998
LO-9-2320-279-12 - Page 33 of 37
NOTES
WARNINGNING
DO NOT START ENGINE OR MOVE VE-
HICLE WHEN ANYONE IS UNDER VE-
HICLE OR WORKING ON BRAKE LINES.
SEVERE INJURY OR DEATH COULD RE-
SULT.
b. Universal
Joints.
Use the proper lubricant
to purge all four bearing seals of each universal
joint. This flushes abrasive contaminants from each
bearing and assures all four bearings are filled prop-
erly. Pop the seals, these seals are made to be
popped.
If any seals fail to purge, move propeller shaft
from side-to-side while applying gun pressure. This
allows greater clearance on thrust end of bearing
that is not purging. If seals still do not purge, rock
vehicle by releasing the parking brake, start engine,
put transmission in D or R, and allow vehicle to roll.
This removes the windup in the drive line and allows
for a greater clearance on the thrust end of the uni-
versal joint. Because of the design of the universal
joint seal, there will occasionally be one or more
bearing seals of a joint that may not purge. Seal ten-
sion then has to be released. The procedure for re-
leasing seal tension is as follows.
NOTE
Universal joint may have one or two grease fit-
tings. If there are two grease fittings, either fit-
ting can be greased. It is not necessary to
grease both fittings.
Loosen bolts holding bearing assembly that does
not purge to release seal tension. It may be neces-
sary to loosen bearing assembly approximately
1/16-inch minimum. If loosening does not result in
purging, remove bearing assembly to determine
cause of blockage.
NOTE
When sure of proper lubrication, run bolts
down until bearing plates are flush to yoke
races, then back off slightly. Retighten to
torque specifications. Bend tabs against sides
of bolt heads to lock bolts in place.
c.
Drive Shaft Slip Joints.
When lubricating
spline end of propeller shafts, apply grease to spline
fitting until lubricant appears at pressure relief hole.
Cover hole with finger and continue adding grease
until it appears at sleeve yoke seal.
d. Severe Operating Conditions.
When ve-
hicle is operating under severe conditions, lubricate
propeller shafts and universal joints every 50 hours.
e. Front Wheel Bearings.
See
TM 9-2320-279-20 for bearing removal and installa-
tion.
f. Pint/e Hook P/ate Lubrication Fitting.
Can
be on any side.
g.
Spring
Hangers.
If spring hanger pin does
not accept grease, relieve load on spring pin by
jacking vehicle up by frame rails as close to spring
pin as possible. If spring pin still fails to take grease,
notify Direct Support Maintenance to remove spring
pin and/or bushing and replace if necessary.
3. ENGINE, TRANSMISSION, HYDRAULIC
SYSTEM.
a. Cooling System Service.
See TM 9-2320-279-10. Coolant level should be up
to bottom of filler neck. Add 3% ratio by volume of
corrosion inhibitor to cooling system.
b. Transmissions.
Operate engine 1 minute at
1000 RPM, then idle until engine temperature
reaches 60-120°F (16-49°C). With engine idling,
check transmission dipstick. If oil level is on or be-
low COLD RUN line, add oil. Approximately 1 Qt
(0.9L) of oil is required to bring oil level from bottom
of COLD RUN band to middle of COLD RUN band.
See TM 9-2320-279-20.
c.
Crankcase.
Check oil level with vehicle
parked on level ground and the engine off and cool.
Do not over fill. Drain crankcase when hot.
d.
Engine
Oil Filter.
Oil filter(s) shall be ser-
viced/cleaned/changed, as applicable, when they
are known to be contaminated, clogged or service
is recommended by AOAP laboratory analysis or at
prescribed hardtime intervals of 3,000 miles (4800
kilometers) or 6 months, whichever occurs first.
When oil samples are rejected and the AOAP rec-
ommends changing lubricant and filter(s), hardtime
filter service clock restarts at “0”. After installing
new filter elements, fill crankcase; operate engine
5 minutes and check housing for leaks. Shut down
engine; check crankcase oil level and bring to full
mark.
e. Army Oil
Analysis
Program (AOAP).
Refer
to TB 43-0210 for sampling requirements.
LO 9-2320-279-12
CARD 33 OF 35
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