TM-9-2320-272-24-3

TRUCK, 5-TON, 6X6, M939, M939A1, AND M939A2 SERIES TRUCKS (DIESEL)

TECHNICAL MANUAL; UNIT, DIRECT SUPPORT, AND GENERAL SUPPORT MAINTENANCE MANUAL; VOLUME 3 OF 4

JUNE 1998

  TM-9-2320-272-24-3 - Page 686 of 799

4-204. BOOM
TM 9-2320-272-24-3
THIS TASK COVERS:
a. Disassembly
b. Cleaning, Inspection, and Repair
INITIAL SETUP:
c. Assembly
d. Vertical Adjustment
APPLICABLE MODELS
M936/A1/A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Arbor press
Mandrel
MATERIALS/PARTS
Cotter pins (Appendix D, Item 68)
Cotter pin (Appendix D, Item 77)
Two locknuts (Appendix D, Item 311)
Twenty-four lockwashers (Appendix D, Item 377)
GAA grease (Appendix C, Item 28)
Drycleaning solvent (Appendix C, Item 71)
REFERENCES (TM)
LO 9-2320-272-12
TM 9-2320-272-24P
TM 9-237
EQUIPMENT CONDITION
Hoist winch removed (para. 4-192).
Inner boom removed (para. 4-195).
Extension cylinder removed (para. 4-196).
Boom rollers removed (para. 4-197).
GENERAL SAFETY INSTRUCTIONS
Keep fire extinguisher nearby when using
drycleaning solvent.
Drycleaning solvent is flammable and toxic. Do
not use near an open flame.
1.
Remove cotter pin (10), crane sheave pin (13), and crane sheave (12) from outer boom (14). Discard
cotter pin (10).
2.
With arbor press and mandrel, remove two bearings (11) from crane sheave (12)
3.
Remove two locknuts (5), screws (17), and spacers (4) from inner boom (9). Discard locknuts (5).
4.
Remove cotter pin (6), cable sheave pin (15), and two cable sheaves (1) from inner boom (9). Discard
cotter pin (6).
5.
Using arbor press and mandrel, remove two sheave bushings (2), thrust washers (3), and spacer (18)
from two cable sheaves (1).
6.
Remove one hundred and four screws (7) and four boom tracks (8) from inner boom (9).
7.
Remove grease fitting (16) from cable sheave pin (15).
WARNING
Drycleaning solvent is flammable and toxic. Do not use near open
flame and always have a fire extinguisher nearby when solvents
are used. Use only in well-ventilated places, wear protective
clothing, and dispose of cleaning rags in approved container.
Failure to do this may result in injury or death to personnel and/or
damage to equipment.
1.
Clean all boom components with drycleaning solvent.
2.
Inspect inner boom (9) and outer boom (14) for bends and cracked or broken welds. If welds are
cracked or broken, refer to TM 9-237. If bent, replace.
3.
Inspect four boom tracks (8) for cracks, breaks, and bends. Replace if cracked, bent, or broken.
4.
Inspect cable sheave pins (13) and (15) for breaks or out-of-round condition. Replace if broken or
out-of-round.
4-950


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