Doosan G643, Руководство по обслуживанию

Страница: 107 / 260

G643 (E) Service Manual Chapter 3. Engine Mechanical System 105
Install or Connect
1 . Valve lifters to the block.
2 . Valve lifter guide and bolts. Note previously
made mark on the valve lifter guide. Reference
mark should be pointing toward front of engine.
Tighten
• Guide bolts to 16 N·m (12 lb· ft.).
3 . Valve pushrods.
A . Seat the valve pushrods into the socket of the
valve lifters.
B . Coat the mating surfaces of the valve rocker
arms and balls with Engine Oil Supplement
GM P/N 1052367 (or equivalent).
4 . Valve rocker arms with balls on to the proper
stud.
5 . Valve rocker arm nuts onto the studs (figure 12-
88). Align the push rod into the valve rocker arm
while tightening valve rocker arm nut. No lash
adjustment is needed.
Tighten
• Valve rocker arm nuts to 25 N·m (18 lb· ft.).
Valve Adjustment
The 4.3L engine has screw-in rocker arm studs with
positive stop shoulders, no valve adjustment is
necessary. When the valve train requires service,
you simply tighten the rocker arm nuts to 25 N·m (18
lb. ft.).
Intake Manifold Installation
Figures 12-89 and 12-90
Install or Connect
1 . Gaskets to the cylinder head with the port
blocking plates facing the rear of the engine.
2 . RTV to the front and rear sealing surfaces on the
block. Apply a 13 mm (1/2 in.) bead of RTV (GM
P/N 1052366) or equivalent to the front and rear
of the block as shown in figure 12-89. Extend the
bead 4 mm (5/32 in.) up each cylinder head to
seal and retain the gaskets.
3 . Intake manifold to the engine.
4 . Intake manifold bolts.
Tighten
• Intake manifold bolts in three steps using
sequence shown in figure 12-90.
- Bolts in sequence to 3 N·m (27 lb. in.).
- Bolts in sequence to 12 N·m (106 lb. in.).
- Bolts in sequence to 15 N·m (11 lb· ft.).
Rocker Arm Cover Installation
Figure 12-91
Install or Connect
1 . New gasket.
2 . Valve rocker arm cover.
3 . Valve rocker arm cover bolts.
Tighten
• Rocker arm cover bolts to 12 N·m (106 lb. in.).