Ford Thunderbird 1958 User Manual

PART
1-ENGINE
1-35
checked
by
measuring
over
the
top
of
the
lobe
with a
micrometer
and
subtracting
the
measurement of the
base
circle
diameter
(Fig.
72).
Check
the camshaft
journal to
bearing
clearances
by
measuring
the
diameter
of
the journals
and the
I.D.
of
the
bearings. If
the clearance ex
ceeds
the wear
limit,
the
camshaft
journals
should be
ground
for under
size
bearings or
the camshaft re
placed,
and/or the bearings
should
be
replaced. Bearings
are available
prefinished to size for standard and
0.015-inch
undersize
journal diame
ters.
Check the distributor
drive
gear
for broken
or chipped teeth.
Remove
light
scuffs, scores,
or
nicks
from
the
camshaft machined
surfaces
with a smooth oilstone.
CRANKSHAFT
CLEANING
AND INSPECTION
Handle
the
crankshaft with care
to avoid possible fractures or dam
age to
the
finished surfaces. Clean
the crankshaft with
solvent,
then
blow
out
all
oil passages with com
pressed
air.
Inspect
main and
connecting
rod
journals for
cracks, scratches,
grooves,
or
scores. Dress minor
im
perfections
with
an
oilstone. Regrind
severely
marred
journals.
Measure the diameter of
each jour
nal
in
at least four places
to
deter
mine
out-of-round,
taper,
or under
size
condition
(Fig. 73).
If the
journals exceed the
wear
limit,
they
should be
reground to size
for the
next
undersize
bearing.
REFINISHING
JOURNALS
Regrind
the
journal to
give the
proper
clearance
with
the
next
under
size
bearing. If the
journal will not
"clean
up"
to give the
proper
clear
ance
with the
maximum undersize
bearing
available,
replace
the
crank
shaft.
Always
reproduce
the same
jour
nal
shoulder
radius that existed
origi
nally. Too
small a
radius
will
result
in
fatigue
failure of the
crankshaft.
Too large
a
radius will
result in bear
ing
failure
due to
radius ride of
the
bearing.
After
grinding,
chamfer the
oil
holes,
then
polish
the
journal
with a
No.
320
grit
polishing
cloth and en
gine
oil.
Crocus
cloth
may
be
used
also
as a
polishing
agent.
Too/-RC-500
535-A
FIG.
74
Cleaning Ring
Grooves
CONNECTING
RODS
The
connecting
rods and related
parts
should
be
carefully
inspected
and checked for conformance to
specifications. Various forms of en
gine wear caused
by
these
parts
can
be
readily
identified.
A
shiny
surface on the pin
boss
side of the piston
usually
indicates
that a
connecting
rod is bent or the
piston pin hole is not
in
proper rela
tion to
the piston skirt
and
ring
grooves.
Abnormal
connecting
rod
bearing
wear
can be
caused
by
either a bent
connecting
rod,
an
improperly
ma
chined
crankpin,
or a
tapered con
necting
rod
bore.
Twisted
connecting
rods will
not
create
an
easily
identifiable wear pat
tern,
but
badly
twisted rods will dis
turb the action
of the
entire
piston,
rings,
and
connecting
rod
assembly
and
may
be the
cause
of
excessive
oil
consumption.
CLEANING AND
INSPECTION
Clean the
connecting
rod
in
sol
vent,
including
the
connecting
rod
bore and the back of
the inserts. Do
not use a caustic
cleaning
solution.
Blow
out all
passages with
com
pressed air.
Inspect
the
connecting
rods
for
signs
of fractures
and the
bearing
bores for
out-of-round
and taper. If
the bore
exceeds
the recommended
limits and/or
if the
rod
is
fractured,
it
should
be
replaced.
Check
the piston pin to
connecting
rod
bushing
clearance.
Replace the
connecting
rod
if the
bushing
is
so
worn
that
it cannot
be
reamed or
honed for an
oversize pin.
Replace
defective
connecting
rod
nuts and
bolts.
Inspect each
bearing
carefully. Re
place
bearings
that
have
a
scored,
chipped,
or worn
surface. For
the
different types of
bearing
failures
and
their
causes refer to
Fig.
77.
Check
the
clearance of
bearings
that
appear
to be
satisfactory. Fit
new
bearings
where
necessary,
following
the recommended
procedure.
After
the
connecting
rods
are
as
sembled to the
piston,
check them
for
bend or twist on a suitable
align
ment
fixture.
Follow
the
instructions
of the
fixture manufacturer.
If
the
bend and/or twist is
excessive,
the
connecting
rod should
be straight
ened
or
replaced.
PISTONS,
PINS,
AND
RINGS
CLEANING
AND
INSPECTION
Remove
carbon
deposits
from the
piston
surfaces
and
from
the
under
side
of
the
piston head.
Clean
gum
or
varnish
from
the
piston
skirt,
pis
ton
pins,
and rings
with
solvent.
Do
not use
a
caustic
cleaning
solution
or
a wire
brush
to
clean
pistons.
Clean
the
ring
grooves
with a
ring
groove
cleaner
(Fig.
74).
Make
sure
the oil
ring
slots
(or
holes)
are
clean.
Carefully
inspect
the
pistons
for
fractures
at
the
ring
lands,
skirt,
and
pin
bosses,
and
for
scuffed,
rough,
or
scored
skirts.
If
the
lower
inner
por
tion
of
the
ring
grooves
have
high
steps,
replace
the
piston.
The
step
will
interfere
with
ring
operation
and
cause
excessive
ring
side
clearance.
Spongy,
eroded
areas
near
the
edge
of
the
top
of
the
piston
are
usually
caused
by
detonation,
or
pre-ignition.

Ford Thunderbird 1958 Specifications

General

Brand	Ford
Model	Thunderbird 1958
Category	Automobile
Language	English