TM 5-3805-260-24
13. LITTLE MOVEMENT OF ROCKER ARM AND TOO MUCH VALVE CLEARANCE
Cause
Correction
Not Enough Lubrication
Check lubrication in valve compartment. There must be a strong flow of oil at
engine rpm, but only a small flow at low rpm. Oil passages must be clean,
especially those sending oil to the cylinder head.
Rocker Arm Parts Worn
If there is too much wear, install new parts or rocker arms. Make adjustment of
valve clearance according to Testing and Adjusting.
End of Valve Stem Worn
If there is too much wear, install new valves. Make adjustment of valve clearance
according to Testing and Adjusting.
Too Much Valve Clearance
Make adjustment according to Testing and Adjusting.
Worn Push Rods
If there is too much wear, install new push rods. Make adjustment of valve
clearance according to Testing and Adjusting.
Cam Followers Worn
If there is too much wear, install new cam followers. Make adjustment of valve
clearance according to Testing and Adjusting.
Worn Cams on Camshaft
Check valve clearance. Check for free movement of valves or bent valve stems.
Check for cam follower wear. Install a new camshaft. Make adjustment of valve
clearance according to Testing and Adjusting.
Loose Bolts Holding Rocker
Tighten to 18 + 5 lb. ft. (24 + 7 N.m).
Arm Assembly
14.
VALVE SPRING LOCK IS FREE
Cause
Correction
Broken Locks
Broken locks can cause the valve to slide into the cylinder. This
will cause much damage.
Broken Valve Spring(s)
Install new valve spring(s).
15. OIL AT THE EXHAUST
Cause
Correction
Too Much Oil in the Valve
Look at both ends of the rocker arm shaft. Be sure that there is a
Compartment
plug in each end.
Worn Valve Guides
Reconditioning of the cylinder head is needed.
Worn Piston Rings
Inspect and install new parts as needed.
16.
LITTLE OR NO VALVE CLEARANCE
Cause
Correction
Worn Valve Seat or Face of
Reconditioning of cylinder head is needed. Make adjustment of
Valve
valve clearance according to Testing and Adjusting.
(Cont. next page) 2-29
