Pontiac FIREBIRD 1972 Service Manual page 1046

7G-8 1972 PONTIAC SERVICE MANUAL
c. Vacuum modulator assembly and valve and pres-
sure regulator valve train.
2. Governor:
a. Valve sticking.
b. Feed holes restricted or leaking.
3. Detent Valve and Linkage
-
stuck open (will cause
high shift points).
4. Control Valve Assembly:
a. 1-2 shift valve train sticking.
b. 2-3 shift valve train sticking.
5. Case
-
porosity*
WON'T HOLD I N PARK
1. Manual Linkage
-
misadjusted (correct alignment in
manual lever shift quadrant is essential).
2. Internal Linkage:
a. Inner lever and actuating rod assembly
-
defective
or improperly installed.
b. Parking pawl
-
broken or inoperative.
c. Parking lock bracket loose, burred or rough edges
or incorrectly installed.
d. Parking pawl disengaging spring missing, broken
or incorrectly hooked.
TRANSMISSION NOISY
C A UTI 0 N
: Before checking transmission for
noise, make certain that the noise is not coming
from the water pump, alternator, power steer-
ing, etc. These components can be isolated by
removing the proper belt and running the en-
gine not more than two minutes at one time.
PARK, NEUTRAL AND ALL DRIVING RANGES
1. Pump Cavitation:
a. Low oil level.
b. Plugged or restricted strainer.
c. Strainer-to-valve body gasket damaged.
d. Porosity in valve body intake area.
e. Water in oil.
f. Porosity or voids at transmission case (pump
face) intake port.
g. Pump-to-case gasket off location.
2. Pump Assembly:
a. Gears damaged.
b. Driving gear assembled backwards.
c. Crescent interference.
d. Oil seal rings damaged or worn.
3. Converter:
a. Loose flexplate-to-converter bolts.
b. Converter damage.
c. Water in oil (causes whine).
FIRST, SECOND AND/OR REVERSE GEAR
Planetary Gear Set:
a. Gears or thrust bearings damaged.
b. Input or output ring gear damaged.
DURING ACCELERATION
-
ANY GEAR
1. Transmission or cooler lines grounded to underbody.
2. Motor mounts loose or broken.
SQUEAL AT LOW VEHICLE SPEED
Speedometer driven gear shaft seal
-
requires lubrication
or replacement.
BURNED CLUTCH PLATES
1. Forward Clutch:
a. Check ball in clutch drum damaged, stuck or
missing.
b. Clutch piston cracked, seals damaged or missing.
c. Low line pressure (see LOW LINE PRESSURE
above).
d. Pump cover oil seal rings missing, broken or un-
dersize; ring groove oversize.
e. Transmission case valve body face not flat or
porosity between channels.