Clutch Plate Diagnosis; Causes Of Burned Clutch Plates - Pontiac TRANS AM 1977 Service Manual

7A1-22 1977 PONTIAC SERVICE MANUAL
4. Parking bracket, loose or
damaged.
TRANSMISSION NOISY
A. Pump Noise
1. Oil level setting low.
2. Cavitation due to plugged
screen, porosity in intake
circuit, water in oil.
3. Pump gears
-
damaged.
-
- -
-
--
B.
Gear Noise
1. Transmission grounded to
body.
2. Roller bearings worn or
damaged.
- - --
-
- .
-
THUMPING OR CLUNKING A. Governor Assembly 1. Governor Spring(s) damaged,
SOUND AT 1-5 MPH
-
mispositioned or tilted.
DRIVE OR INTERMEDIATE
RANGE
CLUTCH PLATE DIAGNOSIS
Composition-Faced Clutch Plates
-
1.
Dry plates and inspect for:
a. pitting and flaking.
b. wear.
c. glazing.
d. cracking.
e, charring.
f. chips or metal particles imbedded in lining.
If composition clutch plate shows any of the above
conditions, replacement is required.
NOTE: Do not diagnose composition-faced clutch
plates by color.
Steel Clutch Plates
-
Wipe plates dry and check for heat discoloration. If the
surface is smooth and an even color smeer is indicated, the
plate should be reused. If severe heat spot discoloration or
surface scuffing is indicated, the plate must be replaced.
Clutch Release Spring
-
Evidence of extreme heat or burning in the area of the
clutch may have caused the springs to take a heat set and
would require replacement of the springs.
CAUSES OF BURNED CLUTCH PLATES
1. Direct Clutch:
a. Check ball in the direct clutch piston damaged, stuck
or missing.
b. Check ball in clutch housing damaged, stuck or
missing.
c. Clutch piston damaged; seals damaged, missing or
rolled over.
d. Low line pressure.
e. Pump cover oil seal rings cut, missing or undersized;
oversize ring groove.
f. Deformed piston retainer and spring assemlby.
g. Mis-assembled clutch pack.
h. Case valve body face not flat or porosity between
channels.
i. Valve body face not flat, porosity between channels or
damaged bores.
j. Pump pressure regulator valve stuck.
k. Pump check ball missing or mis-located.
1. Intermediate servo seals damaged.
2. Forward Clutch:
a. Check Ball in clutch housing damaged, stuck or
missing.
b. Clutch piston damaged, seals damaged or missing.
c. Low line pressure.
d. Turbine shaft oil seal rings cut, missing, broken or
undersize; ring groove oversize; feed hole blocked partially,
interconnected or cup plug missing.
e. Deformed piston retainer and spring assembly.
f. Mis-assembled clutch pack.
g. Case valve body face not flat or porosity between
channels.
h. Valve body face not flat, porosity between channels
or damaged bores.
i. Pump pressure regulator valve stuck.
3. Lo
&
Reverse Clutch:
a. Clutch piston damaged; seals damaged or missing.
b. Low line pressure.
c. Lo
-
reverse clutch housing to case cup plug and seal
damaged, missing or mis-assembled.
d. Mis-assembled clutch pack.
e. Case valve body face not flat or porosity between
channels.
f. Valve body face not flat, porosity between channels or
damaged bores.
g. Pump pressure regulator valve stuck or check ball
missing.