clamps and remove the clamps. Remove
If rocker arms are not marked as
rocker shaft bracket stud nuts and
described, it is imperative that extra
rocker shaft brackets to the cylinder head.
disassembling or assembling rocker
attaching the left side of brackets to the
arms to their shafts to be sure they
cylinder head and remove rocker shaft
are installed in their correct
brackets, shaft, and rocker arms as an
locations. Since there is very little
visual difference in the rocker arms
c. Disassembly. Remove snap ring at each end of
and to prevent the possibility of the
rocker shaft. After loosening the 5/16 inch capscrews in
rocker arms being mixed and
rocker shaft brackets, and the 1/4 inch centering
improperly reinstalled, each rocker
capscrew in the middle bracket, slide rocker arms,
shaft assembly should be kept
brackets, rocker arm retainers, and spring retainers from
separate and rocker arms punched or
marked in some way before removal
d. Cleaning and Inspection.
from their relative shafts so they may
(1) Steel inserts are provided on ends of
be assembled in the same position.
rocker arms and contact the valve bridges
Failure to correctly locate rocker
during opening and closing of the valves.
The inserts are designed so that a
rocker arms with the fuel injection
minimum of side thrust is exerted on the
lines and will not allow centralized
valve mechanism during operation.
contact with the valve bridge
Normally, the inserts will wear very little;
however, if they become worn, the rocker
arms must be replaced since inserts
(1) Remove the valve rocker cover.
cannot be serviced separately.
(2) Disconnect and remove fuel return
(2) Inspect rocker arm bushings for wear.
The specified clearance between shaft
Remove the valve rocker housing if
and bushings is .001 inch-.0025 inch and
must not exceed .005 inch. If bushings
(3) Remove nuts and plain washers securing
are excessively worn, remove bushings
fuel injection nozzle holder
and install new bushings using tools as
installed an oil hole must be drilled in the
bushing in line with oil hole in rocker arm.
pressed through the bushing to establish
the specified .001 inch-.0025 inch
clearance with the shaft. After burnishing,
file bushing so that it is flush with sides of
the rocker arm and remove all burrs with
(3) Inspect rocker arm shaft for wear and
replace if necessary. Clean oil holes in
rocker arms and rocker arm
Figure 49. Rocker arms, shafts, and brackets.