ENGINE OIL FILTER
Oil filter will be changed only when directed by oil analysis laboratory. Remove filter drain
plug, drain oil, and remove filter case assembly (with element) from filter head. Remove
filter element from filter case and inspect for presence of metal particles or water. Discard
element after inspection has been completed. Remove seal ring from filter head and
discard. Clean filter case thoroughly. Check to ensure element end seals are in place and
install new element over spring support assembly. Position new seal ring on filter head with
drain plug pointing down. Tighten center screw 25-35 lb-ft (34-47 N*m). When AOAP
support is not available, change oil filter each 3,000 miles (4,800 kilometers) or 3 months,
whichever occurs first. (Follow procedure outlined in NOTE 2.)
M939A2 series vehicle oil filters will be changed only when directed by oil analysis laboratory. Re-
move spin-on filter head. Drain oil from filter and observe for metal or water contamination. Discard
spin-on filter. Install new spin-on filter. Tighten filter 3/4 turn after seal contacts filter head. When
AOAP support is not available, change oil filter each 3,000 miles (4.800 kilometers) or 3 months,
whichever occurs first. (Follow procedure outlined in NOTE 2). Look under for NOTE 4.
ENGINE FUEL FILTER
Replace every 3,000 miles (4,800 kilometers) or 3 months, whichever occurs first.
Check crankcase breather and tube every 6,000 miles (9,600 kilometers) under normal
operating conditions. When operating under unusual conditions, check crankcase
breather daily. Refer to TM 9-2320-272-20-1.
Change gear lubricant only when required by maintenance repair action, or if con-
taminated by water or other foreign material. Drain only after operation when hot. Place
vehicle in level position. Remove drain and filler plugs from case. If drain plug is magnetic,
check for evidence of metal particles. If bits of metal are seen, notify DS maintenance. After
draining reinstall drain plugs. Fill axle differentials and transfer case within 1/2 inch (12.7
millimeters) of filler plug opening, when lubricant is cold, or to plug level when hot. Fill other
gearcases to plug openings at all times, and install filler plugs. Clean vents after operation in
mud or water.
FRONT AXLE UNIVERSAL JOINTS AND STEERING KNUCKLE BEARINGS
Every 6,000 miles (9,600 kilometers) or 6 months, whichever occurs first, disassemble and
lubricate front axle shaft and universal joints. Refer to TM 9-2320-272-20-1.
Every 3.000 miles (4,800 kilometers) or 3 months, whichever occurs first, lubricate using
low pressure lubrication gun until grease is observed coming from all four trunnions. If
operating conditions are severe or abnormal, service at 1,000 miles ( 1,600 kilometers).
STEERING HYDRAULIC SYSTEM
Do not overfill power steering reservoir. Oil will overflow into
vent system on the M939A1 or thru vent capon the M939A2.
Reservoir level is checked with engine stopped. If engine is cold, fill until oil is visible on
dipstick at mark designated COLD FULL. If engine has been warmed-up, fill until oil is
visible at mark designated HOT FULL. The steering gear receives lubrication from the
power steering pump. If oil in reservoir is contaminated, notify DS maintenance.
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