OPEL GT-R 1973 Service Manual

7C- 801973 OPEL SERVICE MANUAL

DIAGNOSIS
SEQUENCE
1. Check and correct oil level. Refer to Specifications
for checking and refill procedures.
2. Check and correct vacuum line and fittings.
3. Check and correct manual linkage.
4. Road test car using all selective ranges, noting
when discrepancies in operation occur.
5. If engine performances indicates an engine tuneup
is required, this should be performed before road
testing is completed or transmission correction at-
tempted. Poor engine performance can result in
rough shifting or other malfunctions.
CHECKING PROCEDURESBefore diagnosis of any transmission complaint is
attempted, there must be an understanding of oil
checking procedure and what appearance the oil
should have. Many times a transmission malfunction
can be traced to low oil level, improper reading of
dipstick, or oil appearances; therefore, a careful anal-
ysis of the condition of oil and the level may elimi-
nate needless repairs.
When checking oil level in the Opel Three Speed
Automatic Transmission, the procedure outlined in
Specifications should be followed to obtain the most
accurate reading.
Also when the dipstick is removed, it should be noted
whether the oil is devoid of air bubbles or not. Oil
with air bubbles gives an indication of an air leak in
the suction lines, which can cause erractic operation
and slippage. Water in the oil imparts a milky, pink
cast to the oil and can cause spewing.
EXTERNAL OIL LEAKS
Determining source of oil leakBefore 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 clear of all oil
before inspecting for the source of the leak. Red dyeAUTOMATIC TRANSMISSION 7C- 81
is used in the transmission oil at the assembly plant
and will indicate if the oil leak is from the transmis-
sion.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.
3. Inspect for leak with engine running.
4. With engine off, check for oil leaks due to the
raised oil level caused by drain back.
Case Porosity RepairOpel Three-Speed Automatic Transmission external
oil leaks caused by case porosity can be successfully
repaired with the transmission in the car by using the
following recommended procedures:
1. Road test and bring the transmission to operating
temperature, approximately 180 degrees F.
2. Raise car on a hoist or jack stand, engine running,
and locate source of oil leak. Check for oil leaks in
low, drive, and reverse.
3. Shut engine off and thoroughly clean area to be
repaired with a suitable cleaning solvent and a
brush- air dry. A clean, dry soldering acid brush can
be used to clean the area and also to apply the epoxy
cement.
4. Using instructions of the manufacturer, mix a suf-
ficient amount of epoxy, BUICK Group 0.423, Part
No. 1360016, or equivalent, to make the repair. Ob-
serve cautions of manufacturer in handling.
5. While the transmission case is still HOT, apply the
epoxy to the area to be repaired. Make certain the
area to be repaired is fully covered.
6. Allow cement to cure for 3 hours before starting
engine.
7. Road test and check for leaks.

7C- 821973 OPEL SERVICE MANUALAUTOMATIC TRANSMISSION TROUBLE
DIAGNOSIS CHART
Condition
CEllE.e
Concerns Transmission Oil1. Low oil level.a) Oil coming out of oil tiller tube.
b) External oil leak.
c) Failed vacuum modulator.
2. Oil coming out of oil filler
tube.a) Oil level too high.
b) Coolant in transmission oil.
c) External vent clogged with mud.
d) Leak in oil pump suction circuit.
3. External oil leaks in the area
of the torque converter housing.a) Leaking torque converter.
b) Converter housing seal.
c) Sealing washers under converter
housing to case bolts.
d) Sealing washers under converter
housing to pump bolts.
e) Converter housing to case seal.
fj Loose attaching bolts on front of
transmission.
4. External oil leaks in the area
of transmission case and extension.a) Shifter shaft seal.
b) Extension seal.
c) Oil pan gasket.
d) Extension to case gasket.
e) Vacuum modulator gasket.
f) Drain plug gasket.
g) Cooler line fittings.
h) Oil tiller tube seal ring.
i) Detent cable seal ring.
j) Line pressure gauge connection.
5. Low oil pressure.a) Low oil level.
b) Clogged suction screen.
c) Leak in oil pump suction circuit.
d) Leak in oil pressure circuit.
e) Priming valve stuck.
t) Pressure regulator valve malfunction.
g) Sealing ball in valve body dropped out.
6. High oil pressure.a) Modulator vacuum line leaky orinteruupted.
b) Failed vacuum modulator.
c) Leak in any part of engine or
accessory vacuum system.
d) Pressure regulator valve malfunction.
7. Excessrive smoke coming from
exhaust.a) Failed vacuum modulator.
b) Oil from vent valve or leak on hot
exhaust pipe.

AUTOMATIC TRANSMISSION 7C- 83
ConditionCause
Starting
1. No starting in any driverange.a) Low oil level.
b) Clogged suction screen.
c) Manual valve linkage or inner trans-
mission selector lever disconnected.
d) Input shaft broken.e) Pressure regulator valve stuck in open
position. -0 Failed oil pump.
2. No starting in any drive range
for a time. Driving possible only
after repeatedly moving selector
lever to and fro.Manual valve position does not coincide
with valve body channels:
a) Selector lever shaft retaining
pin dropped out.
b) Connecting rod to manual valve
shifting.
c) Selector lever shaft nut loose.
3. No starting after shifting
lever from “P” to “D”, “S”, or “L”
(inadequate engine acceleration).a) Parking
paw1 does not disengage.
4. Sudden starting only after
increase of engine RPM.a) Band servo piston jamming.
b) Low oil level.
c) Oil pump defective.
d) Oil screen missing.
e) Sealing ball in valve body dropped out
5. Heavy jerking when starting.a) Low oil pressure.
b) Wrong modulator valve.
c) Pressure regulator valve stuck.
d) Sealing ball in valve body dropped out.
6. No starting in “D” or “S”
range, but in “L” and “R” range.a) Input sprag installed backwards.
b) Input sprag failure.
7. No starting in “D” or “S” and
“L” (proper driving in “R”; see
also point 9).a) Band worn, does not grip.
b) Band servo piston jamming.
c) Excessive leak in band servo.
d) Parking
paw1 does not disengage.

7C. 841973 OPEL SERVICE MANUALConditionCause8. No starting in “R” range
(proper driving in all other
ranges).a) Reverse clutch failure.
9. Drive in selector lever
position “N”.a) Inadequate selector lever linkage.
b) Planetary gear set broken.
c) Improper adjustment of band.
Gear Change1. No l-2 upshift in “D” and “S”
(transmission remains in 1st gear
at all speeds).a) Governor valves stuck.
b) 1-2 shift valve stuck in 1st gear
position.
c) Seal rings (oil pump hub) leaky.
d) Large leak in governor pressure circuit.
e) Governor screen clogged.
2. No 2-3 upshift in “D” (trans-
mission remains in 2nd gear at all
speeds).a) 2-3 shift valve stuck.
b) Large leak in governor pressure circuit.
3. Upshifts in “D” and “S” only
at full throttle.a) Failed vacuum modulator.
b) Modulator vacuum line leaky or
interrupted.
c) Leak in any part of engine or
accessory vacuum system.
d) Detent valve or cable stuck.
4. Upshifts in “D” and “S” only
at part throttle (no detent
upshift).a) Detent pressure regulator valve stuck.
b) Detent cable broken or misadjusted.
5. Driving only in 1st gear of
“D” and “S” range (transmission
blocks in 2nd gear and “R”).a) “L” and “R” control valve stuck in
“L” or “R” position.
6. No part throttle 3-2 downshift
at low vehicle speeds.a) 3-2 downshift control valve stuck.
7. No forced downshift.a) Detent cable broken or improperly
adjusted.
b) Detent pressure regulator valve stuck.

AlITOMATIC TRANSMISSION 7C- 85
ConditionCtSlSl?8. After full throttle upshifting
transmission shifts immediately
into lower gear upon easing off
accelerator pedal.a) Detent valve stuck in open position,
b) Detent cable stuck.
c) Modulator vacuum line interrupted.
9. At higher speeds, transmission
shifts into lower gear.a) Retaining pin of selector lever shaft
in transmission dropped out.
b) Loose connection of selector lever
linkage to manual valve.
c) Pressure loss at governor.
10. Hard disengagement of selector
lever from “P” position.a) Steel guide bushing of parking
paw1actuating rod missing.
b) Manual selector lever stuck.
Shifts1. Slipping l-2 upshifts (engine
flares).a) Low oil pressure.
b) Sealing ball in valve body dropped out.
c) Second clutch piston seals leaking.
d) Second clutch piston centrifugal ball
stuck open.
e) Second clutch piston cracked or broken.
f) Second clutch plates worn.
g) Seal rings of oil pump hub leaky.
2. Slipping 2-3 upshifts (engine
flares).a) Low oil pressure.
b) Band adjustment loose.
c) Third clutch piston seals leaking.
d) Third clutch piston centrifugal ball
stuck open.
e) Third clutch piston cracked or broken.
f) Wear of input shaft bushing.
g) Sealing ball in valve body dropped out
3. Abrupt l-2 upshift.a) High oil pressure.
b) l-2 accumulator valve stuck.
c) Spring cushion of second clutch broken,
d) Second gear ball valve missing.
4. Abrupt 2-3 upshift.
a) High oil pressure
b) Incorrect band adjustment.
5. Abrupt 3-2 detent downshift at
high speed.a) High speed downshift valve stuck open.
b) Band adjustment.

7C- 881973 OPEL SERVICE MANUAL
Condition
6. Abrupt 3-2 coast downshift.Cause
a) Low speed downshift timing valve
stuck open.
7. Flare on high speed forceda) Low oil pressure.
downshift.b) Band adjustment loose
8. Flare on low speed forced
downshift.a) Low oil pressure.
b) Band adjustment loose.
c) High speed downshift timing valve
stuck in closed position.
d) Sprag race does not grip on 3-1 down shifting
Engine Braking
1. No engine braking in “L” range.a) Selector lever linkage improperly
adjusted.
b) Manual low control valve stuck.
2. No engine braking in “S” range.a) Selector lever linkage improperly
adjusted.
3. No park.a) Selector lever linkage improperly
adjusted.
b) Parking lock actuator spring.
c) Parking pawl.
d) Governor hub.
Noises1. Excessive noises in all drive
ranges.a) Too much backlash between sun gear
and planetary gears.
b) Lock plate on planetary carrier loose.
c) Thrust bearing defective.
d) Bearing bushings worn.
e) Excessive transmission axial play.
f) Unhooked parking paw1 spring contacts
governor hub.
g) Converter balancing weights loose.
h) Converter housing attaching bolt
loose and contacting converter.
2. Screaching noise when starting.
3. Short vibrating, hissing noise
shortly before 1-2 upshift.a) Converter failure.
a) Dampening cushion of reverse clutch
wearing into transmission case.
Abrasive
1. Excessive amount of iron dust
(can be picked up by magnet
in oil pan).a) Oil pump.
b) Governor hub.
c) Second clutch hub
2. Excessive amount of aluminum
dust (cannot be picked up by
magnet) in oil pan.a) Thrust face in case.
b) Rear bore of case.
c) Stator thrust washer
- check
converter end clearance.

AUTOMATIC TRANSMISSION 7C- 87
HYDRAULIC PRESSURE CHECK SHIFT POINTS
SPECIFICATIONSHYDRAULIC PRESSURE CHECKSNOTE: ON REPLACING PLUG, TOROUE TO 6.7 LEFT.
D65
4. After pressure gage and hose is install&, replace rear
crossmembers65
and side bolts and proceed with pressure checking procedure.L80NOTE: PRESSURES ARE OFF OF THE SERVO APPLY.OPERATING CONDITIONS
Detent Downshift Possible

7C- 881973 OPEL SERVICE MANUALCONVERTER
OUT\
/
2ND CLUTCHa!EI1
CONVERTER iOUT
x
PRIMING VALVE
BORE
\
REVERSE
CLUTCH
:. -q
MODULATOR -
EXHAUST
REVERSE CLUTCH
INTERMEDIATE
2ND CLUTCH
3RD CLUTCHBOOST
7674Figure 7C-74 Oil Pump Passages

AUTOMATIC TRANSMISSION 7C- 89
DRIVESERVO
LINE
REVERSEI
,NTERMEDlATE\T
SERVO APPLYMODULATOR OR
Figure 7C75 Valve Body Top