Pontiac FIREBIRD 1972 Service Manual page 1047

TURBO HYDRA-MATIC (M-38) TRANSMISSION 7G-9
2. Intermediate Clutch: 3. Inspect for leak with engine running.
a. Intermediate clutch piston seals damaged or
4.
With engine off, check for oil leaks due to the raised
missing.
oil level caused by drain back.
b. Low line pressure (see LOW LINE PRESSURE
above).
POSSIBLE POINTS OF OIL LEAKS
c. Transmission case valve body face not flat or
TRANSMISSION OIL PAN LEAK
porosity between channels.
1. Attaching bolts not correctly torqued.
3. Direct Clutch:
Restricted orifice on vacuum line to modulator
(poor vacuum response).
Check ball in clutch drum damaged, stuck or
missing.
Defective modulator bellows.
Clutch piston cracked, seals damaged or missing.
Transmission case valve body face not flat or
porosity between channels.
Intermediate overrun roller clutch installed back-
wards.
In addition, burned clutch plates can be caused
by incorrect usage of clutch plates. Also, anti-
freeze in transmission fluid can cause severe dam-
age, such as large pieces of clutch plate material
peeling off.
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 engine and transmission.
The suspected area should be wiped clean of all oil before
inspecting 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 locate the point at which
the oil is leaking is helpful. Comparing the oil from the
leak to that on the engine or transmission dipstick, when
viewed by black light, will determine the source of the leak
-
engine or transmission.
Oil leaks around the engine and transmission are generally
carried toward the rear of the car by air stream. For
example, a transmission oil filler tube to case leak will
sometimes appear as a leak at the rear of the transmission.
In determining the source of a leak, proceed as follows:
1. Degrease underside of transmission.
2. Road test to get unit at operating temperature.
2. Improperly installed or damaged pan gasket.
3. Oil pan gasket mounting face not flat.
EXTENSION HOUSING LEAK
1. Attaching bolts not correctly torqued.
2. Rear seal assembly damaged or improperly installed.
3. Square seal, extension-to-case, damaged or improp-
erly installed.
4. Porous casting*.
CASE LEAK
1. Filler pipe "0" ring seal damaged or missing; mispo-
sition of filler pipe bracket to engine.
2. Modulator assembly "O" ring seal damaged or im-
properly installed.
3. Detent cable connector O-ring seal damaged or im-
properly installed.
4.
Governor cover not tight, gasket damaged or leak
between case face and gasket.
5. Speedometer gear "0" ring damaged.
6. Manual shaft seal damaged or improperly installed.
7. Line pressure tap plug loose.
8. Vent pipe (refer to OIL COMES OUT VENT PIPE
below).
9. Porous casting*.
FRONT END LEAK
1. Front pump seal leaks.
a. Seal lip cut. Check converter hub, etc.
b. Bushing moved and damaged. Oil return hole
plugged.