TM-9-2320-361-24-1
2-1/2 TON, 6X6, M44A2 SERIES TRUCKS
TECHNICAL MANUAL; FIELD AND SUSTAINMENT MAINTENANCE PART 1 OF 2
AUGUST 2006
TM-9-2320-361-24-1 - Page 140 of 1176
TM 9-2320-361-24-1
0008 00
0008 00-12
MECHANICAL SYSTEMS TROUBLESHOOTING - DIRECT SUPPORT (Contd)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
16. ENGINE NOISE
ABNORMAL
NOTE
When abnormal engine noise is
evident, engine should be checked
and location of noise determined to
ensure engine will not be
permanently damaged.
1. When a knocking noise is located
at front of engine, check camshaft
gear, crankshaft gear, or fuel
injection pump gear for damage,
excessive backlash, or loose fit.
Check excessive camshaft end
play. Remove timing gear cover
(WP 0032 00).
2. When a knocking noise is located
at top of engine, remove rocker
arm covers (WP 0030 00) and
check valve train components
mounted on cylinder heads for
wear, defects, or incorrect
adjustment (WP 0031 00).
3. When knocking noise is located at
side of engine, remove side tappet
chamber covers, valve covers,
valve train components and
tappets. Check for defects.
4. When a knocking noise is located
at bottom or rear of engine, check
flywheel screws for loose
conditions. Position in neutral,
start engine, and press and
release clutch a number of times.
5. When a knocking noise is located
at bottom of engine, remove oil
pan, (WP 0035 00) and check
condition of bearings, crankshaft
and rods for wear and defects.
6. Disassemble engine and check
connecting rod wrist pins and
pistons for wear and defects.
1. If gears are loose on shafts,
tighten or replace gears
(TM 9-2815-210-34-2-1).
2. If gears are worn, defective, or
have excessive backlash, replace
engine (WP 0046 00).
3. If camshaft end play is excessive,
replace engine (WP 0046 00).
1. If valve train components are
worn or are defective, replace
(WP 0031 00, and WP 0034 00).
2. If valve train components are out
of adjustment, adjust
(WP 0031 00).
If valve train components are
excessively worn or defective, replace
(WP 0031 00, and WP 0034 00).
If noise changes, remove
transmission (WP 0131 00) and
clutch (WP 0050 00) and check
flywheel screws for loose condition.
Tighten loose screws or replace
damaged or defective flywheel
components (WP 0029 00).
1. If bearings are worn or defective,
replace engine (WP 0046 00).
2. If crankshaft or connecting rods
are defective or damaged, replace
engine (WP 0046 00).
3. If worn or defective, replace
engine (WP 0046 00).
Table 1. Engine Troubleshooting Procedures (Contd).
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