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7-88
GROUP 7-AUTOMATIC TRANSMISSION
(Fig. 9).
FRONT CLUTCH
Apply air pressure to the transmis-
sion case forward clutch or front
clutch passage
(Fig.
9
).
A dull thud
can be heard when the clutch piston
is applied. If no noise is heard, place
the finger tips on the
input shell
and
again apply air pressure to the for-
ward or front clutch passage. Move-
ment of the piston can be felt as the
clutch is applied.
REAR SERVO
Apply air pressure to the rear
servo apply passage
(Fig.
9), move-
ment of the servo piston stem indi-
cates correct operation.
If the servo does not operate, dis-
assemble, clean, and
inspect
to locate
the source of the trouble.
If
air
pressure
applied
to either of
the clutch passages
fails
to operate
a clutch or operates both clutches at
once, remove and, with
air
pressure,
check the fluid passages
in
the
case
and front pump to detect obstruc-
tions.
GOVERNOR
Apply air pressure to the control
pressure to governor passage
(Fig.
9)
and listen for a sharp clicking or
whistling noise. The noise indicates
governor
valve
movement.
REAR CLUTCH
Apply air pressure to the reverse-
high clutch or rear clutch passage
(Fig. 9). A dull thud indicates that
the reverse-high or rear clutch piston
has moved to the applied position. If
no noise is heard, place the finger tips
on the clutch drum and again apply
air pressure to detect movement of
the piston.
FRONT SERVO
Hold the air nozzle
in
the front
servo apply tube or the intermediate
servo apply passage. Operation of the
servo is indicated by movement of
the servo piston stem. Continue to
apply air pressure to the servo apply
tube or passage, and introduce air
pressure into the front release tube
or the intermediate servo release
pressure. The front or intermediate
servo should release the band against
the apply pressure.
HYDRAULIC SYSTEM BENCH
TESTS
After the transmission has been as-
sembled and is ready for installation
in the vehicle, check the hydraulic
system to make sure it is operating
properly. These hydraulic tests can
be made on the bench so that most
malfunctions of the system can be
corrected before the transmission is
installed in the
vehicle.
TESTING TOOL
INSTALLATION
1.
Install
a
plug in the filler tube
hole in the
case
or fluid pan, and pour
about four quarts of clean transmission
fluid
into
the transmission through the
Tool-7003
D 1062·C
FIG. 11 -Bench
Testing Tool
Installation- Typical
B
COMMON ADJUSTMENTS
AND REPAIRS
TRANSMISSION FLUID LEVEL
CHECK
The transmission fluid level should
be checked using the following pro-
cedure.
I.
Make sure that the vehicle is
standing level; then firmly apply the
parking brake.
2. Run the engine at normal idle
speed. If the transmission fluid is
cold, run the engine at fast idle
speed (about 1200 rpm) until the
fluid reaches its normal operating
temperature. When the fluid is warm,
slow the engine down to normal idle
speedometer gear opening.
2. Remove the vacuum diaphragm
unit and the diaphragm unit
control
rod, and reinstall the vacuum unit
if
these parts had been previously in-
stalled.
3. Install the bench testing tool
on
the transmission.
4. Remove the 1/8-inch pipe plug
at the transmission
case.
Turn the
front pump in a clockwise direction
at 75-100 rpm until
a
regular flow
of transmission fluid leaves the hole
in the transmission
case.
This
opera-
tion bleeds the
air
from the pump.
5. Install
the
pressure
gauge
(77820 or T57L-77820-A) as
shown in
Fig. 11.
PRESSURE TESTS
Turn the front pump
at
75-100
rpm and note the
gauge
readings.
The pressure readings on
the
bench
test must be within the limits
as
out-
lined
in
Figure 7, for the engine idle
check.
If pressure gauge readings are
within limits in all selector lever po-
sitions,
install
the vacuum diaphragm
control rod unit.
DIAGNOSIS GUIDE
The Diagnosis Guide (Fig.
22)
lists the
most common trouble
symptoms that may be found and
gives the items that should be checked
to find the cause of the trouble.
The items to
check
are arranged
in a logical sequence which
should
be followed for quickest
results.
The
letter symbols for each
item
are ex-
plained in the key. If
items
A, B, C,
K, and the stall tests have
already
been
checked
during
preliminary
checks
and
adjustments, they need
not be repeated.
speed.
3. Shift the selector lever
through
all positions, and place the
lever at
P. Do not turn off the engine during
the fluid level checks.
4. Clean
all
dirt from the trans-
mission fluid dipstick
cap
before re-
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