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PART 7-2-· C4 AUTOMATIC TRANSMISSION
7-43
control valve body assembly. The
inoperative units can be located by
introducing air pressure into the
transmission case passages leading
to
the
clutches,
servos,
and
governor.
FORWARD CLUTCH
Apply air pressure to the transmis-
sion case forward 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 forward
clutch passage. Movement of the
piston can be felt as the clutch is
applied.
GOVERNOR
Apply air pressure to the control
pressure to governor passage and
listen for a sharp clicking or whist-
ling noise. The noise indicates secon-
dary governor valve movement.
REVERSE-HIGH CLUTCH
Apply air pressure to the reverse-
high clutch passage (Fig. 9). A dull
thud indicates that the reverse-high
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.
INTERMEDIATE SERVO
Hold the air nozzle in the inter-
mediate servo apply passage (Fig.
9). Operation of the servo is in-
dicated by a tightening of the inter-
mediate band around the drum.
Continue to apply air pressure into
the intermediate servo apply pass-
age, and introduce air pressure into
the intermediate servo release pass-
age. The intermediate servo should
release the band against the apply
pressure.
CONTROL
PRE SSURE
TO PRIMAR
Y
THR OTTLE VALVE
PRIMARY THROTTLE
PRE SSURE TO VALVE
BODY
PRIMAR
Y
THROTTLE
VALVE EXHAUST
FIG. 9- Oil Pressure Passage Holes
LOW-REVERSE SERVO
Apply air pressure to the low-
reverse apply passage
(Fig.
9). The
low-reverse band should tighten
around the drum if the servo is
operating properly.
If the servos do not operate, dis-
assemble, clean and inspect them to
locate the source of the trouble.
If air pressure applied to any
clutch passage fails to operate the
clutch or operates more than one
clutch at once, remove and, with
air pressure, check the fluid pass-
ages in the case and front pump to
detect obstructions.
If the passages are clear, remove
the clutch assemblies, and clean and
inspect the malfunctioning clutch to
locate the trouble.
COMMON ADJUSTMENTS AND REPAIRS
TRANSMISSION FLUID DRAIN,
AND REFILL
.
Normal maintenance and lubri-
cation requirements do not neces-
sitate periodic automatic transmis-
sion fluid
changes.
If a major failure, such as a
clutch, band, bearing, etc., has
occurred within the transmission,
it will have to be removed for ser-
vice. At this time the converter
must be thoroughly flushed to
remove all dirt.
When filling a dry transmission
and converter, install 5 quarts of
fluid. Start the engine, shift the
selector lever as in Step 5 below,
and
check
and
add
fluid
as
necessary.
Following is the procedure for
CON
V
ER
TER
IN
0217 1-A
DIAGNOSIS GUIDE
The Transmission Diagnosis
Guide page 7-44 lists the most com-
mon trouble symptoms that may be
found in the transmission, and gives
the items that should be checked to
find the cause of the
trouble.
The items to check for each
trouble symptom 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 to the Diagnosis
Guide.
If items
A,
B. C, D, E, and the
stall test have already been checked
during the preliminary checks and
adjustments, they need not be re-
peated when following the
Diagnosis
Guide.
partial drain and refill due to minor
repairs.
1. Place a drain pan under the
transmission. Loosen and remove
all but two of the oil pan bolts,
from the front of the case and drop
the rear edge of the oil pan to drain
the fluid. Remove and thoroughly
clean the oil pan and screen. Dis-
card the oil pan gasket.
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