Yanmar 4TNV98, Service Manual

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4TNV98 & 4TNE98 Diesel Engine Section 3. Engine 84
Removal of Rocker Arm Assembly
1. Remove the fuel injectors from the cylinder head.
See Removal of Fuel Injectors on page 163.
2. Remove the bolts (Figure 6-41, (1)) that retain the
rocker arm shaft supports to the cylinder head.
3. Remove the rocker arm and shaft assembly from
the cylinder head.
NOTE : Identify the push rods and valve bridges so
they can be installed in their original locations.
4. Remove the push rods (Figure 6-41, (2)) .
5. Remove the valve bridge assemblies (Figure 6-
41, (3)) . Remove the seat (Figure 6-41, (4)) from
each valve bridge.
6. Identify all parts so that they will be reinstalled in
their original locations.
Figure 6-41
Disassembly of Rocker Arm Assembly
NOTE : Identify the rocker arms so they can be
reinstalled with the original matching valve and
pushrod.
1. Remove the rocker arm shaft alignment studs
(Figure 6-42, (5)) from the rocker arm shaft
supports (Figure 6-42, (6)) .
2. Slide the supports, wave washers (Figure 6-42,
(7)) , rocker arms (Figure 6-42, (8)) , and fuel
injector retainers (Figure 6-42, (4)) off the rocker
shaft (Figure 6-42, (1)) , leaving these parts in
order on the bench surface.
Figure 6-42
NOTE : Figure 6-42 shows components for one
cylinder. Components for all remaining cylinders are
assembled in the same order.
3. Remove the valve adjusting screw (Figure 6-42,
(2)) and the lock nut (Figure 6-42, (3)) from the
rocker arms.