TM 55-1930-209-14&P-21
Section VI. Rocker Arms and Cylinder Head
6-14 General
a. Rocker arms
(1) Three rocker arms are provided for each of four cylinders; two outer arms operate exhaust valves and
center arm operates fuel injector.
(2) Each set of three rocker arm assemblies pivots on a separate shaft supported by two brackets. A single
bolt secures each bracket to top of cylinder.
(3) The rocker arms are operated by camshaft through cam followers and short push rods extending through
cylinder head as illustrated in Figure 6-11.
(4) The valve and Injector mechanism Is lubricated by oil from a longitudinal oil passage on camshaft side of
cylinder head, which connects with oil passages in cylinder block. Oil from this passage enters drilled rocker arm shafts
through lower end of drilled rocker shaft bracket bolts.
b. Cylinder Head. Cylinder head is a one piece casting. It can be removed from cylinder block as an
assembly consisting of cam followers, cam follower guides, rocker arms, exhaust valves, and fuel Injectors.
6-15 Cylinder head maintenance
a. Disassembly of cylinder head
NOTE
When removing cam followers and associated parts, tag them so they may be reinstalled In their
original location.
(1) Rest cylinder head on its side and remove cam follower guide.
(2) Pull cam follower out of cylinder head.
(3) Loosen push rod locknut and unscrew push rod from rocker arm clevis.
(4) Pull push rod and spring assembly from bottom of cylinder head.
(5) Remove push rod locknut, spring, and spring seats from pushrod.
(6) Remove rocker arms and pushrods.
(7) Remove fuel injectors if they have not already been removed.
(8) Disassemble fuel Injector control tube in numerical sequence as illustrated In Figure 6-12.
(9) Remove exhaust valve guides as illustrated In Figure 6-13.
(10) Support cylinder head, bottom side up, on wooden blocks which are at least three Inches thick.
Remove exhaust valve guides using a removal tool and drive guides out of head.
(11) Place cylinder head on Its side and remove exhaust valve seat Insert as Illustrated in Figure 6-14.
(12) Place Injector tube removal tool in injector tube; then thread pilot Into end of removal tool and remove
injector tube.
6-27
