Forward Clutch - Buick LeSabre 1965 Service Manual

SUPER TURBINE " 4 0 0 "
TROUBLE DIAGNOSIS 5 - 1 4 9
tube connected for normal modu-
and with the_
RPM. NOTE:
lator operation,
engine at 1200
Pressures are not significantly
affected by altitude or barometric
pressure when the vacuum tube
is connected.
Drive,
Neutral,
Park
70
5-43
or
150
Reverse
107
TRANSMISSION
OIL LEAKS
Before attempting to correct an
oil leak, the actual source of the
leak must be determined. In many
cases the source of the leak can
be deceiving due to "wind flow"
around the e n g i n e and
transmission.
The suspected area should be
wiped clean of all oil before in-
specting for the source of the
leak. Red dye is used in the
transmission oil at the assembly
plant and will indicate if the oil
leak is from the transmission.
The use of a "black Light" to
identify the oil at the source of
leak is also helpful. Comparing
the oil from the leak to that on
the engine or transmission dip-
stick (when viewed by black light)
will determine the source of the
leak.
Oil leaks around the engine and
transmission are generally car-
ried toward the rear of the car
by the air stream. For example,
a transmission "oil filler tube to
case leak" will sometimes appear
as a leak at the rear of the trans-
mission. In d e t e r m i n i n g the
source of an oil leak it is most
helpful to keep the engine running.
5 - 4 4 POSSIBLE POINTS
OF TRANSMISSION
OIL LEAKS
1. Transmission Oil Pan Leak
a. Attaching bolts not correctly
torqued.
b. Improperly installed or dam-
aged pan gasket.
c. Oil pan gasket mounting face
not flat.
2. Rear Extension Leak
a. Attaching bolts not correctly
torqued.
b. Rear Seal Assembly - damaged
or improperly installed.
c. Square Seal - (Extension to
Case) damaged or improperly
installed.
d. Porous casting.
3. Case Leak
a. Filler pipe "O" ring seal
damaged or missing; misposition
of filler pipe bracket to engine -
"loading" one side of "O" ring.
b. Modulator assembly "O" ring
seal - damaged or improperly
installed.
c. Governor cover, gasket and
bolts - damaged, loose; case face
leak.
d. Speedo g e a r - "O" ring
damaged.
e. Manual shaft seal - damaged,
improperly installed.
f. Line p r e s s u r e tap plug -
stripped, shy sealer compound.
g. Vent pipe (refer to Item 5
below)
h. Porous case.
4. Front End Leak
a. Front Seal - damaged (Check
converter neck for nicks, etc.,
also for pump bushing moved for-
ward); garter spring missing.
b. Pump attaching bolts and seals
- damaged, missing, bolts loose.
c. Converter - leak in weld.
d. Pump "O" ring seal-damaged.
(Also check pump groove and case
bore.)
e. Porous casting (pump or case).
5. Oil Comes Out Vent Pipe
a. Transmission over-filled.
b. Water in oil.
c. Pump to c a s e g a s k e t
mispositioned.
d. Foreign material between pump
and case, or between pump cover
and body.
e. Case - Porous, pump face im-
properly machined.
f. Pump - Shy of stock, porous.
5 - 4 5 SUPER TURBINE 4 0 0
DIAGNOSIS GUIDE
TRANSMISSION
PROBLEMS AND
RELATED CAUSES
L No Drive In Drive Range -
(Install Pressure Gauge)
A. Low oil level
1. Correct level - check for ex-
ternal leaks or defective vacuum
modulator (leaking diaphragm will
evacuate oil from unit).
B. Manual linkage
1. Maladjusted; correct alignment
in manual lever shift quadrant
essential.
C. Low oil pressure - (Refer
to oil p r e s s u r e t a b l e for
specifications)
1. Strainer Assembly - "O" ring
missing or damaged, neck weld
leaking, strainer blocked.
2. Pump Assembly - Pressure
Regulator; pump drive gear -
tangs damaged by converter.
3. Case - porosity in intake bore.
D. Control valve assembly
1. Manual v a l v e disconnected
from manual lever pin.
E. Forward clutch
1. Forward clutch does not apply-
piston cracked; seals missing,
damaged; clutch plates burnt.
2. Pump feed circuit to forward
clutch oil seal rings missing,