Pontiac FIREBIRD 1972 Service Manual page 895

TURBO HYDRA-MATIC (M-40) TRANSMISSION 7E-5
c. Too many pressure regulator valve spacers. 6. Case Assembly:
d. Pressure boost valve installed backwards or de- a. Porosity in intake bore area.
fective.
b. Check case for intermediate clutch cup plug leak
e. Pressure boost bushing broken or defective. or blown out.
f. Pump casting bad.
LOW LINE PRESSURE
Low transmission oil level.
Defective vacuum modulator assembly.
Filter Assembly:
a. Blocked or restricted.
b. "0" Ring seal on intake pipe and/or grommet
omitted or damaged.
c. Split or leaking intake pipe.
d. Wrong filter assembly.
Oil Pump:
a. Pressure regulator and/or boost valve stuck.
b. Pressure regulator valve spring too weak.
c. Not enough spacers in pressure regulator.
d. Gear clearance, damaged, worn, drive gear in-
stalled backwards.
e. Pump-to-case gasket mispositioned.
f. Defective or mismatched pump body/pump
cover.
j .
Internal Circuit Leaks:
a. Forward clutch leak (pressure low in Drive range
-
pressure normal in Neutral and Reverse)
-
(1) Check pump oil seal rings.
(2) Check forward clutch seals.
b.
Direct clutch leak (pressure low in Reverse, pres-
sure normal in all other ranges)
-
(1) Check center support oil seal rings.
(2) Check direct clutch outer seal.
(3) Check rear servo and front accumulator pis-
tons and rings for damage or missing.
NOTE: See Fig. 7E-158 for location of inter-
mediate clutch cup plug.
c. Lo-reverse check ball mispositioned or missing
(this will cause no reverse and no overrun braking
in Lo range).
1-2 SHIFT-FULL THROTTLE ONLY
1. Detent switch sticking or defective (may stick in cold
or wet weather). Can be detected by pulling connec-
tion at transmission and obtaining normal upshifts.
2. Detent solenoid:
a. Loose.
b. Gasket leaking.
c. Sticks open.
3. Control valve:
a. Valve body gaskets
-
leaking, damaged, incor-
rectly installed.
b. Detent valve train stuck.
c. 3-2 valve stuck.
4. Case
-
porosity.
FIRST SPEED ONLY, N O 1-2 SHIFT
1. Governor:
a. Valve sticking.
b. Driven gear loose, damaged or worn (check for
pin in case and length of pin showing); also check
output shaft drive gear for nicks or rough finish
if driven gear shows damage.
2. Control valve:
a. 1-2 shift valve train stuck closed.
b. Governor feed channels blocked, leaking, pipes
out of position, governor screen plugged.