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8-10
3. Place a 5116-inch steel ball
in the plunger cup
(Fig.
4).
4. Adjust the length of the ram
so that the pointer is l/16-inch
below the starting mark when the
ram contacts the valve lifter plung-
er (Fig. 5) to facilitate timing as
the pointer passes the Start Timing
Mark.
Use the center mark on the point-
er
scale as the Stop Timing point
instead of the original Stop Timing
mark at the top of the scale.
5.
Work the valve lifter plunger
up and down until the lifter fills
with fluid and all traces of air bub-
bles have disappeared.
6. Allow the ram and weight to
force the valve lifter plunger down-
ward. Measure the exact time it
takes for the. pointer to travel from
the Start Timing to the Stop Tim-
ing marks of the
tester.
7. A valve lifter that is satisfac-
tory must have a leak-down rate
(time in seconds) within the mini-
mum and maximum limits
specified.
8. If the valve lifter is not within
specifications, replace it with a new
lifter.
Always test a new lifter be-
fore installing It in the engine. It is
not necessary to disassemble and
clean new valve lifters before test-
ing, because the oil contained in
new lifters is test
fluid.
9. Remove the fluid from the cup
and bleed the fluid from the lifter
by depressing the plunger up and
down. This step will aid in de-
pressing the lifter plungen when
checking the valve clearance.
POSITIVE CRANKCASE
VENTILATION SYSTEM TEST
A malfunctioning positive crank-
FIG. 6- Crankcase Ventilation
System Tester -Typical
GROUP 8-
ENGINE
case ventilation system may be in-
dicated by loping or rough engine
idle. Do not attempt to compensate
for this poor idle condition by dis-
connecting the crankcase ventilation
system and/or making carburettor
adjustments. The removal of the
crankcase ventilation system from
the engine will adversely affect the
fuel economy and engine ventilation
with resultant shortening of engine
life.
To determine whether the loping
or rough idle condition is caused
by a malfunctioning crankcase ven-
tilation system, perform
either
of
the following tests.
- -
Regulator
Valve
Test.
Install a known good regulator
valve in the crankcase ventilation sys-
tem.
Start the engine and compare the
engine idle condition to the prior idle
condition.
If the idle condition is found
to
be
satisfactory,
replace
the
regulator
valve and clean the hoses, fittings.
etc.
If the loping or rough idle condi-
tion remains when the good regulator
valve is installed, the crankcase venti-
lation regulator valve is not at fault.
Check the crankcase ventilation sys-
tem for restriction at the intake mani-
fold or carburetor
spacer.
If the sys-
tem is not restricted, further engine
component diagnosis will have to be
conducted to find the malfunction.
Air Intake Test.
I.
With the engine at normal oper-
ating temperature, remove the oil fill-
er cap
.
2. Hold the tester C8AZ-6B627-A
over the opening in the valve
cover.
Make sure that the surface is flat to
form a seal between the cover and
tester. If the cover is distorted, shape
it as required to make an air tight
seal. An air leak between the cover
and tester will render the tester ino-
perative.
3. Start the engine and allow it to
operate at the
recommended idle
speed.
4. Hold the tester over the oi I filler
cap opening making sure that there is
a positive seal between the tester and
cover.
5.
If the ball settles in the Good
(green) area, the system is functioning
properly.
If the ball settles in the Re-
pair (red) area, clean or replace the
malfunctioning
components as
re.
quired.
6. Repeat the test after repairs are
made to make sure that the crankcase
ventilation system is operating satis-
factorily.
CRANKSHAFT END PLAY
1.
Force the crankshaft toward
the rear of the engine.
2. Install a dial indicator so that
the contact point rests against the
crankshaft flange and the indicator
axis is parallel to the crankshaft axis
(Fig.
7).
3. Zero the dial indicator. Push
the crankshaft forward and note the
reading on the dial.
4. If the end play exceeds the
wear limit, replace the thrust bear-
ing. If the end play is less than
the
minimum limit, inspect the
thrust bearing faces for scratches,
burrs, nicks or dirt. If the thrust
faces are not defective or dirty, they
probably were not aligned properly.
Install the thrust bearing and align
the faces following the procedure
recommended under Main Bearing
Replacement in the pertinent en-
gine
section.
Check the crankshaft
end play.
FLYWHEEL FACE RUNOUT-
MANUAL-SHIFT
TRANSMISSIONS
Install a dial indicator
so
that the
indicator point bears against the
fly-
wheel face (Fig.
8).
Turn the
fly-
wheel making sure that it is full for-
ward or rearward so that crankshaft
end play will not be indicated as tly-
wheel runout.
If the clutch face runout exceeds
the specifications, remove the fly-
wheel and check for burrs between
the flywheel and the face of the
crankshaft mounting flange. If no
burn exist, check the runout of the
FIG. 7 -Typical Crankshaft End
Play
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