TM 9-2320-272-24-3
4-53. VALVE ADJUSTMENT
THIS TASK COVERS:
Adjustment
INITIAL SETUP:
APPLICABLE MODELS
PERSONNEL REQUIRED
M939A2
TWO
SPECIAL TOOLS
REFERENCES (TM)
Engine barring tool (Appendix E, Item 43)
TM 9-2320-272-24P
TOOLS
EQUIPMENT CONDITION
General mechanic’s tool kit (Appendix E, Item 1)
Valve cover removed (para. 3-6).
MATERIALS/PARTS
O-ring (Appendix D, Item 444)
Chalk (Appendix C, Item 17)
Assistant will help with this procedure.
Adjustment
1.
Remove plug (8) and O-ring (7) from flywheel housing (6). Discard O-ring (7).
Ensure timing pin is pulled out after top dead center is reached.
Failure to do so may damage timing pin.
2.
Using engine barring tool, rotate crankshaft (9) clockwise and engage timing pin (10).
3.
Make aligning chalk marks (12) on vibration damper (13) and front gearcase cover (11).
4.
Loosen twelve locknuts (1), and back off adjusting screws (2) counterclockwise from push rods (5).
Step 5 through 8 are performed for each cylinder.
5.
Place feeler gauge, between rocker lever head (3) and valve stem (4).
6.
Adjust valve clearance to proper limits. Refer to table 4-7, Valve Clearance Adjustment Limits, step A
7.
Tighten adjusting screw (2) until a slight drag is felt on feeler gauge.
8.
Tighten locknut (1) 18 lb-ft (24 N-m).
9.
Rotate crankshaft (9) clockwise one full turn and realign chalk marks (12).
10.
Adjust valve clearance to proper limits using table 4-7
11.
Install new O-ring (7) and plug (8) in flywheel housing (6).
Table 4-7. Valve Clearance Adjustment Limits.
CYLINDER
STEP A
STEP B
1
I and E
2
I
E
3
E
I
4
I
E
5
E
I
6
I and E
Valve clearance setting:
I = Intake valve gap
0.012 in. (0.30 mm)
E = Exhaust valve gap
0.024 in. (0.61 mm)
4-326