TM-9-2320-260-34-1

TRUCK, 5-TON, 6X6, M809 SERIES (DIESEL)

TECHNICAL MANUAL; DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE; VOLUME 1 OF 2

JULY 1994
TM-9-2320-260-34-1

  TM-9-2320-260-34-1 - Page 25 of 657

TM 9-2320-260-34-1
Table 2-1. Mechanical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
19.
NOTE
When flywheel is loose on crankshaft., damage to flywheel/crank-
shaft mating surfaces can occur. Inspection of mating surfaces
should be performed prior to tightening flywheel screws.
Step 4. If a knocking noise is located at bottom or rear of engine, check flywheel for loose condition.
Place transmission in neutral, start engine, and press and release clutch a number of times
(TM 9-2320-260-10).
a. If noise changes, remove transmission and clutch (paras. 8-4 or 8-5 and 4-2) and check
flywheel screws and pilot bearing for damage and loose condition.
b. Tighten loose screws or replace flywheel parts if worn or defective (para. 3-21).
c. Replace pilot bearing if damaged (para. 4-2).
Step 5. If a knocking noise is located at bottom of engine, remove oil pan (para. 3-20) and check
condition of main bearings, crankshaft, and connecting rods for wear and defects.
a. Replace main bearings and crankshaft if worn or defective (para. 3-48).
b. Replace connecting rods if worn or defective (para 3-47).
c. If no defects are found, remove pistons and connecting rods and check connecting rod
wrist pins and pistons for wear and defects. Replace defective components (para. 3-47).
END OF TESTING!
ENGINE VIBRATION ABNORMAL
Step 1. Check for loose or defective crankshaft vibration damper.
a. If vibration damper is loose, check woodruff key and crankshaft and vibration damper
mating surfaces for damage. Replace damaged components (paras. 3-5 and 3-48).
b. Replace vibration dampener if defective (para. 3-5).
Step 2. Check engine cylinders compression readings (malfunction 12).
Step 3. Complete troubleshooting malfunction 9.
END OF TESTING!
FUEL SYSTEM
WARNIN G
Diesel fuel is flammable. Do not perform troubleshooting checks
near open flame, sparks, or electricity. Injury to personnel may
result.
Eye protection is required when performing fuel system trouble-
shooting checks. Failure to wear eye protection may result in
injury to personnel.
Ignition switch must remain off during fuel system trouble-
shooting checks except when necessary to perform malfunction
check. Failure to turn ignition system off may result in injury to
personnel.
2-11


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