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

  TM-9-2320-272-24-3 - Page 36 of 799

TM 9-2320-272-24-3
4-46. FRONT GEARCASE HOUSING AND TIMING PIN MAINTENANCE
THIS TASK COVERS:
a. Front Gearcase Housing Removal
b. Timing Pin Removal
c. Cleaning and Inspection
d. Timing Pin Installation
e. Front Gearcase Housing Installation
INITIAL SETUP:
APPLICABLE MODELS
REFERENCES (TM)
M939A2
TM 9-2320-272-24P
SPECIAL TOOLS
EQUIPMENT CONDITION
Engine barring tool (Appendix E, Item 43)
Engine mounted on repair stand (para. 4-9).
TOOLS
Rocker levers and pushrods removed (para. 4-41).
General mechanic’s tool kit (Appendix E, Item 1)
Vibration damper removed (para. 4-42).
Front gearcase cover removed (para. 4-48).
Torque wrench (Appendix E, Item 144)
Fuel injection pump removed (para. 4-57).
MATERIALS/PARTS
O-ring (Appendix D, Item 445)
Gasket (Appendix D, Item 191)
Gasket (Appendix D, Item 192)
Sealing compound (Appendix C, Item 68)
Antiseize compound (Appendix C, Item 10)
Gasket compound (Appendix C, Item 29)
a. Front Gearcase Housing Removal
NOTE
Assistant will help with step 1.
1.
Locate Top Dead Center (TDC) for cylinder No. 1. While turning engine, push down on timing
pin (2) until timing pin (2) enters hole (3) in camshaft (1).
2.
Remove four screws (13), washers (14), and front engine mount (15) from gearcase housing (5).
3.
Remove four front oil pan screws (11), washers (10), and washers (9) from gearcase housing (5) and
oil pan (12).
4.
Remove twenty-four screws (4), gear housing (5), and gasket (6) from engine block (7). Discard
gasket (6).
b. Timing Pin Removal
1.
Remove ring (19), timing pin (2), and O-ring (18) from timing pin housing (17). Discard O-ring (18).
2.
Remove two torx screws (20), timing pin housing (17), and gasket (16) from gearcase housing (5).
Discard gasket (16).
c. Cleaning and Inspection
1.
For general cleaning instructions, refer to para. 2-14.
2.
For general inspection instructions, refer to para 2-15.
3.
Repair or replace all parts failing inspection.
4.
Inspect oil pan gasket (8) for tears. If torn, replace oil pan gasket (8) (para. 4-47).
4-300


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