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7-84
GROUP 7-AUTOMATIC TRANSMISSION
leakage. Raise the vehicle on a hoist
and run the engine at fast idle, then at
engine idle, occasionally shifting to
the drive and reverse ranges to in-
crease pressure within the transmis-
sion. Observe the front of the fly-
wheel, back of the block (in as far
as possible), 3nd inside the converter
housing and front of the transmission
case. Run the engine until fluid leak-
age is evident and the probable source
of leakage can be determined
.
CONVERTER LEAKAGE
CHECK
During the above fluid leakage
checks, if there are indications that
the welds on the torque converter are
leaking, the converter will have to be
removed and
the following check
made before the unit is replaced.
A leak checking tool (Fig. 2) can
be made from standard parts. The
tool can be used to check all con-
verters
.
I. Install the plug in the converter
(Fig
.
3)
and expand it by tightening
the
wing
nut.
Attach
the safety
chains.
2. Install the air valve in one of the
drain plug
holes.
3. Introduce air pressure into the
converter.
Check the pressure with a
tire gauge and adjust it to 20 psi.
4. Place the converter in a tank
of water. Observe the weld areas for
bubbles
.
If no bubbles are observed,
it may be assumed that the welds are
not leaking.
ENGINE IDLE SPEED CHECK
Check and, if necessary, adjust the
engine idle speed, using the proce-
dure given in Group
10.
If the idle speed is too low, the en-
gine will run roughly
.
An idle speed
that is too high will cause the vehicle
to creep when the transmission is
shifted
into gear and
will cause
rough transmission
engagement.
MANUAL LINKAGE CHECKS
Correct
manual
linkage
adjust-
ment is necessary to position the
manual valve for proper fluid pressure
direction to the different transmission
components.
Improperly
adjusted
manual
linkage may cause cross-
leakage and subsequent transmission
failure. Refer to Linkage Adjust-
ments in
7-22 for detailed
manual linkage adjustment proce-
dures.
~·
STEEL PLATE
o/a•
X 1
¥.•;
DRILL TO SUIT
SPACER-
82Q-9438-A
PLUG
RUBBER PLUG
1
Y2•
DIA.
X 2•
LONG
Y2·
HOLE THRU
APPROXIMATELY
40 DUROMETER
STANDARD BOLT
Y2·-13 X
-4
1
/2•
LONG SQUARE
CHAIN, 1
0'
LONG
ST ANOARD
THREAD END
WELD TOGETHER
REMOVE HEAD
VAL VI
FIG. 2- Converter Leak Checking Tool
~
............. Tire Preuure Gauge
D106--A
FIG. 3 - Typical Converter Leak
Checking Tool
CONTROL PRESSURE AND
VACUUM DIAPHRAGM UNIT
CHECK
When the vacuum diaphragm unit
is operating properly and the down-
shift linkage is adjusted properly, all
the transmission shifts (automatic and
kickdown) should occur within the
road speed limits specified in
page 7-126
If the shifts do iiot occur within
limits or the transmission slips during
shift point, the following procedure
is suggested
to determine engine,
transmission, linkage, vacuum dia-
phragm unit or valve body problems.
SECURELY -MUST
AND WELD TO
NOT LEAK
WASHER
STANDARD l/8" FITTING-87971 ·S FOR
RETAPPED DRAIN PLUG THREADS·USE
l
/
4" OVERSIZE FITTING-87973·S
D
l067·
B
1. Attach a tachometer to the
engine and a vacuum gauge to the
transmission vacuum line at the
vacuum unit (Fig. 4).
2. Attach the pressure gauge to the
control pressure outlet at the trans-
mission (Fig. 5).
3.
Firmly apply the parking brake
and start the engine
.
4. Adjust the engine idle speed to
the specified rpm. If the engine idle
speed cannot be brought within lim-
its by adjustment at the carburetor
idle
adjustment screw,
check
the
throttle and downshift linkage for a
binding condition. If the linkage is
satisfactory, check for vacuum leaks
in the transmission diaphragm unit
(Fig.
6) and its connecting tubes and
hoses.
Check all other vacuum oper-
ated units (such as the power brake)
for vacuum
leaks.
VACUUM UNIT CHECK
To check the vacuum unit for dia-
phragm
leakage,
remove the unit
from the: transmission
.
Use a distrib-
utor tester equipped with a vacuum
pump
(Fig. 6).
Set the regulator
knob so that the vacuum gauge reads
18 inches with the end of the vacuum
hose blocked off.
Then connect the
~·acuum
hose to
the transmission vacuum unit. If the
gauge sti II reads 18 inches, the vac-
uum unit diaphragm is not leaking.
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