Advertisement
MAIN
BEARING PLATE
'
SHIMS
Fig. 35
71682C
keep
shims in place. See Fig. 35.
The
shims
are used
to give the proper end
play
to the Ti mken main bear-
ings
or. :.he crankshaft.
This
end
play
should
be .002
to
.004
inch when engine is
cold.
There is practical-
ly
no wear in these Timken
bearings so that read-
justment is seldom
necessary
after proper assembly.
When
rea~sembling
crankshaft, the punch marks on
the
crankshaft gear and the camshaft gear must be
matched,
otherwise engine
will not
operate
properly
or
if timing
is off considerably, engine will
not run
at all. Sec Fig. 34.
Tighten rna
in
bearing plate capscrews 25
to
32
foot
pounds torque.
CAMSHAFT
AND
VALVE TAPPETS
The camshaft is held
in
the
crankcase
and
revolves
on
a
stationary pin which
is known as the
camshaft
support pin.
In
order
to
remove
the
camshaft,
the
pin
should be driven out of the crankcase,
from the
take-
off end of the engine. This
is
accomplished
by the
Fig.
36
71G83C
21
INNElt
r
OY. LEVER
?-
OUTER
I
GOY lEVER
0
IHRUST WASHER
I
..
'
GOV. GEAR
STOP PIN
Fig.
37
~
CAMSHAFT
SUPPORT PIN
71672C
use
of
a large drift punch
or similar
tool.
As soon as
the
support
pin
is removed,
the camshaft assembly,
together with the tappets
will drop out of the case.
See Fig's. 36 and 37.
In reassembly, the ta ppcts
are fitted to the guides in
the
cylinder
with a
clearance .0005
lo
.
0025 inch. The
tappets
s hould
be
held in
place and the camshaft and
gear assembly
re-installed.
The camshaft support pin
must be
driven
through the case
from
the flywheel
end of the ·engine
and
tapped flush with the pad on
which
the
main bearing plate mounts. The
support pin
is fitted
to
the camshaft with a clearance
of
.
001 to
.0025 inch. The
camshaft
plug on the
flywheel
end
should
be replaced to
seal
in the support
pin.
Adjust
tappets
as expla1ned
tn
'Valve 1 appct 4djuSt-
ment',
Page 19.
OIL PUMP
Remove the 2 remaining capscrews
and
lockwashers
and
lift the crankcase
off
the engine
base.
The oil
trough
is
secured
to
the engine base by 2
capscrews
and lockwashers. These
should be
remov-
ed and the trough
can
be pulled
free of
the
base.
The
oil
trough
can
be
tipped to the
side and the oil
pump plWlger, spring, retainer and
check balls
will
fall
out
of
the pump.
All parts
of
the pump
should be thorough Jy washed
in
solvent
to remove
all
traces
of
th1ckcned
oil and
sludge.
The
oil pump
plunger
should
be
fitted
to the
bore with a clearance
of .003
to .004 inch.
If the
clearance
is
greater
than .008
inch,
the
plunger and
oil pump body should be replaced. Inspect the
check
ball seat in the bottom
of
the
pump cylinder. This
seat must be cleaned perfectly,
and must
not
be worn
or
pitted. The
check
ball
should
then
be dropped
1nto
the
cylinder
and tapped
into
the seat lightly
with
a
punch and
hammer.
The retainer
should then be put
in place
a
nd
the
spring
lowered intothc
cylinder bore.
Ml-226
4
Advertisement
