or dirt from entering the valve mech-
4. Install the bolts finger tight, draw
anism. Then loosen the bolts and lift the
them down snug and then tighten to the
cover straight up from the cylinder
specified torque. Draw the bolts down
head. Use a new gasket when reinstal-
in the proper sequence (Figure 11B-68)
ling the cover.
for each of these steps to draw the mat-
ing
parts
together
evenly,
thus
Before the cover is installed on a cylin-
providing a good seal. Tighten the bolts
der head, it is important that the silicone
to 55-60 lb-ft (75-81 Nm) torque.
gasket be properly installed in its groove
in the rocker cover.
5. Install the rear lifter bracket to the
cylinder head and flywheel housing in a
1. Clean and blow out the groove in the
similar manner.
rocker cover with compressed air. Oil in
the groove or on the silicone gasket will
make it difficult to install.
VALVE ROCKER COVER
2. Press the stem side of the new Y
shaped gasket down into the groove at
Description
the four corners of the cover first.
Then press the remainder of the gasket
The valve rocker cover assembly
into
place
in
the
groove
(see
(Figure 11B-69 on page 11B-45) com-
Figure 11B-69 on page 11B-45). Be sure
pletely encloses the valve and injector
the stem of the entire gasket bottoms in
rocker arm compartment at the top of the
the groove.
cylinder head. the top of the cylinder
head is sealed against oil leakage by a
gasket located in the groove of the lower
NOTE
rail of the cover.
When the gasket is completely in-
stalled in the groove it should not
The rocker cover is held in place by
fall out.
3/8"-16 twelve point head shoulder bolts
with a steel washer and silicone isolator.
The bolts have a shoulder which bottoms
3 . B e f o r e i n s t a l l i n g t h e r o c k e r cover,
out against the cylinder head. The iso-
lubricate the cylinder head rail and the
lators
and
gasket
use
low
flat surface of the gasket with a thin film
compression-set materials which provide
of engine oil. This will keep the gasket
long s e a l i n g l i f e a n d m i n i m i z e e n g i n e
from sticking to the cylinder head rail.
noise levels. Tighten the bolts to 15-20
lb-ft (20-27 Nm) torque.
CRANKSHAFT
Description
The shorter rocker cover bolt,
which threads into the throttle de-
The crankshaft is a one-piece steel forg-
lay bracket, can crack the bracket
ing, heat treated to ensure strength and
if overtightened. Also, the rocker
durability. All main and connecting rod
cover bolt is especially designed
for this purpose and must not be
bearing journal surfaces are induction
replaced with an ordinary bolts.
hardened.
Complete static and dynamic balance of
the crankshaft has been achieved by
The valve rocker cover assembly in-
counterweights incorporated in the
cludes: a breather assembly and an oil
crankshaft. The crankshaft end play is
filler.
controlled by thrust washers located at
the rear main bearing cap of the engine.
Full pressure lubrication to all connect-
R e m o v e and Install Valve Rocker Cover
ing rod and main bearings is provided by
drilled passages within the crankshaft
Clean the valve rocker cover before re-
and cylinder block.
moving it from the engine to avoid dust
