TM-9-2320-272-24-1
TRUCK, 5-TON, 6X6, M939, M939A1, AND M939A2 SERIES TRUCKS (DIESEL)
TECHNICAL MANUAL; UNIT, DIRECT SUPPORT, AND GENERAL SUPPORT MAINTENANCE MANUAL; VOLUME 1 OF 4
JUNE 1998
TM-9-2320-272-24-1 - Page 586 of 1015
3-78. ALTERNATOR
TM 9-2320-272-24-1
THIS TASK COVERS:
a. Removal
b. Inspection
c. Installation and Adjustment
APPLICABLE MODELS
REFERENCES (TM)
M939/A1
TM 9-2320-272-10
TOOLS
TM 9-2320-272-24P
General mechanic’s tool kit (Appendix E, Item 1)
EQUIPMENT CONDITION
Belt tension gauge (Appendix E, Item 16)
Parking brake set (TM 9-2320-272-10).
Torque wrench (Appendix E, Item 144)
Right splash shield removed (TM 9-2320-272-10).
Prybar
Hood raised and secured (TM 9-2320-272-10).
NOTE
For replacement of alternator/fan drivebelt on M939A2 series
vehicles, refer to paragraph 3-71.
1.
Loosen screws (3) and (6) at adjusting link (2). Do not remove screws (3) and (6).
2.
Loosen two screws (9) at alternator mounting bracket (10). Do not remove screws (9).
3.
Push alternator (1) toward engine (5) until slack exists in two alternator belts (8). Remove two
alternator belts (8) from alternator pulley (4) and vibration damper (7).
Inspect two alternator belts (8) for breaks, cracks, or splits. Replace if broken, cracked, or split.
1.
2.
3.
4.
5.
Alternator belts must be replaced as matched sets.
Position two alternator belts (8) over vibration damper (7) and alternator pulley (4).
Insert prybar between engine (5) and alternator (1) and pull prybar down until alternator belts (8)
appear tight.
Tighten screw (3) on adjusting link (2) 15-20 lb-ft (20-27 N•m).
Tighten screw (6) on adjusting link (2125-31 lb-ft (34-42 N•m).
Using belt tension gauge, check for proper belt tension. Tension of new belts (8) should be 95-105 lb
(423-467 N). Tension of used belts (8) should be 85-95 lb (378-422 N). Replace belts (8) if they cannot
be adjusted.
6.
Tighten two screws (9) on mounting bracket (10) 39-49 lb-ft (53-66 N•m).
NOTE
3-222
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