TM 9-2320-272-24-4
5-9. CAMSHAFT AND GEAR MAINTENANCE
THIS TASK COVERS:
d. Cleaning and Inspection
a. Check Backlash
b. R e m o v a l
e. Assembly
c . Disassembly
f. I n s t a l l a t i o n
INITIAL SETUP:
APPLICABLE MODELS
MATERIALS/PARTS
M939/A1
Seven cam bushings (Appendix D, Item 34)
Camshaft bushing (Appendix D, item 33)
SPECIAL TOOLS
Lubricating oil (Appendix C, Item 50)
Drycleaning solvent (Appendix C, Item 71)
Telescoping gauge (Appendix E, Item 136)
Cam bushing replacement tool (Appendix E,
REFERENCES (TM)
Item 26)
TM 9-2320-272-24P
TOOLS
EQUIPMENT CONDITION
General mechanic's tool kit (Appendix E, Item 1)
l Engine oil pan removed (para. 4-22).
Dial indicator (Appendix E, Item 36)
l Piston and connecting rod installed (para. 5-10).
Puller kit (Appendix E, Item 102)
Outside micrometer (Appendix E, Item 80)
GENERAL SAFETY INSTRUCTIONS
Vernier caliper (Appendix E, Item 159)
Brass rod
l Keep tire extinguisher nearby when using
drycleaning solvent.
l Drycleaning solvent is flammable and toxic. Do
not use near an open flame.
a. Check Backlash
1.
Attach dial indicator to engine block (3) and rotate camshaft gear (2) as far as it will freely move
and hold it in place. Ensure crankshaft gear (1) does not move.
2.
Position dial indicator arm to camshaft gear (2) tooth and set dial indicator to zero.
3.
Rotate camshaft gear (2) in opposite direction and read backlash measurement as rotation stops. If
backlash is not 0.002-0.020 in. (0.05-0.51 mm), replace camshaft gear (2).
NOTE
Normal backlash is 0.0045-0.0105 in. (0.114-0.267 mm) on new
gear with a minimum of 0.002 in. (0.05 mm).
b. Removal
Rotate camshaft gear (2) and camshaft (4) slightly and remove from engine block (3).
CAUTION
Use care when removing camshaft to avoid damaging bearings.
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