Pontiac FIREBIRD 1972 Service Manual page 894

7E-4 1972 PONTIAC SERVICE MANUAL
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(3) Restricted orifice in governor valve.
Drive, Neutral,
Park Super or Lo Reverse b. Governor Feed System
-
60 150 107
Fig. 7E-3 Oil Pressure Check
-
Vehicle Stationary, Vacuum
Tube Connected
4. If no oil pressure drop occurs (and transmission is
malfunctioning), inspect:
a. Governor Assembly
-
(1) Stuck governor valve.
(1) Check governor screen in transmission case.
(2) Check for restrictions in governor pipe.
(3) Scored governor bore.
5. If a pressure drop of 7 psi or more occurs (and trans-
mission is malfunctioning), disassemble, clean and
inspect the control valve assembly.
(2) Stuck governor weight(s).
TURBO HYDRA-MATIC (M-40) TROUBLE DIAGNOSIS GUIDE
NO DRIVE I N DRIVE RANGE
-
(INSTALL
a. Vacuum line disconnected.
PRESSURE GAUGE)
b. Leak on line from engine to modulator.
1. Low oil level
-
check for external leaks or defective
c. Improper engine vacuum.
vacuum modulator (leaking diaphragm will evacuate
oil from unit).
d. Leak in vacuum-operated accessory (hoses,
vacuum advance, etc.).
2. Manual linkage maladjusted (correct alignment in
manual lever shift quadrant is essential); manual
2. Modulator:
valve disconnected from manual lever pin.
a. Stuck modulator valve.
3. Low oil pressure
-
refer to LOW LINE PRESSURE
b. Water in modulator.
below.
4. Forward clutch:
c. Damaged, not operating properly.
a. Clutch does not apply
-
piston cracked; seals
3. Detent System:
missing, damaged; clutch plates burnt (see
BURNED CLUTCH PLATES below).
a. Detent switch actuated (plunger stuck) or
shorted.
b. Pump feed circuit-to-forward clutch oil seal rings
missing or broken on pump cover; leak o r restric-
b. Detent wiring shorted.
tion in feed circuits; pump-to-case gasket misposi-
tioned or damaged. Clutch drum ball check stuck
c. Detent solenoid stuck open.
or missing.
d. Detent feed orifice in spacer plate blocked or re-
5. Roller Clutch
-
broken springs, damaged cage or in-
stricted.
stalled backwards.
e. Detent solenoid loose.
HlGH OR LOW OIL PRESSURE
(Refer to OIL PRESSURE CHECKS)
HlGH LINE PRESSURE
f. Detent valve bore plug damaged.
g. Detent regulator valve pin short.
4. Oil Pump:
a. Pressure regulator and/or boost valve stuck.
1. Vacuum Leak: b. Incorrect pressure regulator valve spring.