TM 5-4310-354-14
Section XVII. MAINTENANCE OF ENGINE ROCKER ARM GROUP
4-49. General. Maintenance of the engine rocker arm
b. Checking Clearance (Cold Engine).
group at Organizational level, is limited to checking and
adjustment of the valve stem-to-rocker arm clearance.
(1) Remove nuts and washers that secure
cylinder head cover, remove cover and
gasket.
4-50. Engine Rocker Arm.
a. Checking Clearance (Warm Engine).
(2) Rotate the engine crankshaft by hand or
with the starting motor until both intake
(1) Start the engine and allow to run until
and exhaust valves of number 1 cylinder
operating temperature is achieved.
are fully closed. The valves are fully
closed when number 1 cylinder is at top
(2) Remove nuts and washers that secure
dead center.
cylinder head cover, remove cover and
gasket.
(3) Use a 0.016 or 0.017-inch feeler gauge
(0.40-0.43 mm) and check clearance as
(3) With engine running at slow idle, check
shown in figure 4-32.
the clearance between each rocker arm
and the end of valve stems using a 0.015-
(4) When properly adjusted, there should be a
inch feeler gauge (0.38 mm) as shown in
slight pull when removing feeler gauge.
(5) Check remaining valve clearances in the
same manner in the cylinder firing order of
1, 2, 4, 3 by rotating crankshaft in normal
rotation direction.
(6) After all valves have been adjusted as
specified in para 4-50.c below, recheck
clearance as instructed for warm engine,
c. Rocker Arm Adjustment.
(1) Adjust setting of adjusting screw so that a
slight drag on feeler gauge is felt while
checking clearance as shown in figure
4-50.b above.
(2) The adjusting screws are self-locking and
require no lock nuts.
TS5-4310-354-14/4-32
(3) Repeat adjustment procedure for all
Figure 4-32. Rocker arm-to-valve stem clearance,
valves, intake and exhaust. All valves
checking and adjustment.
have the same clearance.
(4) After checking and adjustment is
(4) When properly adjusted, there will be a
complete, reinstall cover gasket (new
slight drag on the feeler gauge when the
gasket as necessary), cylinder head
valve is in the unoperated (closed)
cover, and secure with washers and nuts.
position.
4-61
