TM 9-2320-272-24-3
4-53. VALVE ADJUSTMENT
THIS TASK COVERS:
Adjustment
INITIAL SETUP:
PERSONNEL REQUIRED
APPLICABLE MODELS
TWO
M939A2
REFERENCES (TM)
SPECIAL TOOLS
TM 9-2320-272-24P
Engine barring tool (Appendix E, Item 43)
EQUIPMENT CONDITION
TOOLS
Valve cover removed (para. 3-6).
General mechanic's tool kit (Appendix E, Item 1)
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.
STEP B
STEP A
CYLINDER
1
I and E
Valve clearance setting:
I
E
2
I = Intake valve gap
I
E
3
0.012 in. (0.30 mm)
E
I
4
E = Exhaust valve gap
E
I
0.024 in. (0.61 mm)
5
I and E
6
4-326
