1973 OPEL GT-R check engine

2. If inspection of contact points indicates excessive
burning, pitting or wear, check condenser and re-
place if necessary.
3. Inspect all connections and wires in the primary
ignition circuit. Correct any abnormal conditions
found.Carburetor1. Clean fuel strainer in fuel pump. To prevent fuel
leakage in pump, disconnect “IN” line from pump
and raise end above fuel level. The in-line fuel filter
should be replaced every 12,000 miles or every 12
months.
2. Check for freedom of choke valve operation and
clean shaft if necessary, with suitable solvent.
3. Inspect throttle cable or linkage bracket and re-
turn spring for wear. With helper depressing acceler-
ator pedal to floor, check for wide open throttle.
Adjust accelerator pedal height so wide open throttle
is obtained when pedal is within
l/2 inch from floor.
Lubricate linkage pivot points with engine oil.
Air CleanerCheck paper element every 6,000 miles and replace
every
24,ooO miles. If a vehicle is operated in dusty
territory, check condition of air cleaner element
more frequently and replace if necessary.
Fan Belt1. Inspect belt for wear, cracks or frayed points.
Replace and/or adjust as necessary. Specified ten-
sion for belt using Gauge J-23600 is 45 lbs.
Cooling System1. Inspect the radiator, water pump, cylinder head
areas and all radiator and heater hose connections
for evidence of engine coolant leaks.
2. Inspect all hoses for deterioration from gas and oil
contact. Correct as required.
Inspection should be made with engine operating at
normal temperature, cooling system completely
filled, temperature control lever fully open and nor-
mal pressure in the system. Normal pressure should
be 13.2 to 15.2 psi.
Engine Lubrication SystemInspect engine for evidence of oil leakage. Correctany abnormal condition with sealastic or new seals
and gaskets.
Battery
1. Inspect battery, battery mount and cables and
check electrolyte level. Proper level should be just
above the cell plates.
CAUTION:Do not over fill.
2. Determine the serviceability of the battery by ap-
plying the 421 Battery Test.
Positive Crankcase VentilationClean crankcase ventilator metered orifice in the in-
take manifold fitting every 6,000 miles. Also all hoses
and fittings should be inspected, cleaned and re-
placed, if necessary.
To clean, remove rubber hose from metered orifice
and apply air pressure to orifice to remove any for-
eign particles that may be trapped.
Valve Lifter AdjustmentRefer to Engine Mechanical and Mounts section for
valve lifter adjustment procedure.
Engine Tune-Up Instrument ChecksThe following instrument checks and adjustments
serve as a final check on engine condition. These
checks may discover some new problems that may
not have been obvious before. The engine is also
given its final adjustments that will assure maximum
performance, reliability, and proper emission con-
trol.
Refer to Electrical Group for checking procedures of
the following:
Cranking Voltage Check
Ignition Timing
Distributor Advance
Ignition Output
Secondary Resistance
Current Output and Voltage Setting
Idle Speed and Mixture AdjustmentsRefer to carburetor section.

7A- 21973 OPEL SERVICE MANUALDIAGNOSIS
CLUTCH TROUBLE DIAGNOSIS
ConditionPossible Cause
CorrectionFails to release (pedal
1. Improper cable1. Adjust cable.
pressed to floor
- shiftadjustment.
lever does not move
freely in and out of
“Reverse” gear.
2. Faulty pilot bearing.2. Replace bearing.
3. Faulty driven plate.3. Replace driven plate.
4. Yoke off ball stud.4. Install properly.
5. Clutch driven plate hub5. Repair or replace main drive
binding on main drive gear
gear.spline.
Slipping1. Improper adjustment (no1. Adjust cable.
lash).2. Oil-soaked driven plate.2. Install new driven plate and
correct oil leak at its source.
3. Worn facing or facing3. Replace driven plate.tofn from driven plate.
4. Warped pressure plate or4. Replace same.
flywheel.
5. Weak diaphragm spring.5. Replace cover assembly.
6. Driven plate not seated6. Make 20-50 normal starts.
in.7. Driven plate overheated.7. Allow to cool
- check lash.
Grabbing1. Oil on facing or burned1. Repair oil leak and install
or glazed facings.new driven plate.
2. Worn splines on main2. Replace transmission main drive
drive gear.gear.
3. Loose engine mountings.3. Tighten or replace mountings.
4. Warped pressure plate or4. Replace pressure plate or
flywheel.flywheel.
5. Burned or smeared resin5. Sand off if superficial, replace
on flywheel or pressureburned or heat checked parts.
plate.

7A- 61973 OPEL SERVICE MANUAL1. FIywheeI and Pressure PlateExamine friction surfaces of flywheel and pressure
plate for scoring or roughness. Slight roughness may
be smoothed with fine emery cloth, but if surface is
deeply scored or grooved the part should be re-
placed.
2.
CJutch Driven Plate
Inspect driven plate for condition of facings, loose
rivets, broken or very loose torsional springs.
If facings are worn down near rivets or are oily, the
plate assembly should be replaced. A very slight
amount of oil on clutch facings will cause clutch grab
and chatter. A large amount of oil on facings will
cause slippage. Removal of oil by solvents or by buff-
ing is not practical since oil will continue to bleed
from facing material when hot.
When oil is found on driven plate facings, examine
transmission drainback hole, pilot bushing, engine
rear main bearing and other points of possible oil
leakage.
Test the fit of driven plate hub on transmission main
drive gear for an easy sliding fit.
Regardless of whether the old plate or a new one is
to be installed, the plate should be checked for run-
out. Lateral run-out measured at disc circumference
should not exceed
.016 inch.
Inspect clutch release bearing for scoring or exces-
sive wear on front contact face. Test for roughness of
balls and races by pressing and turning front race
slowly. Inspect main drive gear pilot bushing in
crankshaft. If bushing is rough or worn it should be
Figure JA-3replaced. If replacement is necessary, remove bear-
ing with Tool J-21718 and Slide Hammer J-7004-1.
Install new bearing using J-21706. See Figure 7A-3
for removal procedure and Figure 7A-4 for installa-
tion.
\,,
Figure JA-4
Installation of Clutch1. Index alignment marks on clutch assembly and
flywheel. Place driven plate on pressure plate with
long end of splined hub facing forward toward the
flywheel. See Figure 7A-5.
2. Insert alignment Tool J-22934 through clutch
cover and driven plate.
3. Hold complete assembly against flywheel while
inserting end of Tool J-22934 into pilot bearing in
crankshaft.
4. Index the alignment marks and install four (4)
clutch cover to flywheel bolts finger tight. Complete
torquing bolts alternately and evenly one at a time.
5. Torque attaching bolts to 36 lb.ft. and remove
alignment tool.
6. Install release bearing.
7. Install flywheel housing and torque lower bolts to
36
lb.ft.8. Install flywheel housing lower cover.
9. Install clutch return spring and control cable.
10. Install transmission. See Manual Transmission
Section for procedure.
11. Adjust clutch control cable. Refer to paragraph7A-3.

7C- 561973 OPEL SERVICE MANUALMODULATORFigure
7C-42 Low Speed Downshift Timing Valve
During a “coast” condition, the vacuum is high and
the modulator pressure is zero. The spring holds the
timing valve in a bottomed position and the servo
release pressure is exhausted through a restricting
orifice, thus delaying the apply of the servo.
During a “power on” 3-2 downshift at lower car
speeds, the servo must be applied rapidly. During
such a shift, the vacuum will be somewhat lower and
the resulting modulator pressure will force the valve
over against the spring. This provides an unrestricted
passage for servo release, thus permitting rapid apply
of the servo.
High Speed Downshift Timing Valve
When a 3-2 downshift is “forced” at high car speeds,
the application of the band must be delayed. Servo
apply pressure is directed through the high speed
downshift timing valve. See Figure
7C-43.The timing valve is held in a bottomed position by
the spring at lower car speeds. This permits an unre-
stricted
flow for servo apply. At higher car speeds,
approximately 25 to 35 MPH, (depending on axle
ratio and engine), governor pressure forces the valve
over against the spring. This closes off the direct feed
to servo apply and the feed is controlled by a fixed
orifice.While it may outwardly appear that the functions of
the two downshift timing valves are contradictory,
whether or not the application of the band is delayed
during a 3-2 downshift is a combined function of car
speed and throttle position.
--Figure
7C-43 High Speed Downshift Timing Valve
Second Clutch Orifice Valve
For reasons of shift timing, it is necessary to have
different restricting orifice sizes for the feed and ex-
haust of the second clutch. This is accomplished by
introducing a “one way” ball check in the second
clutch circuit. See Figure
7C-44.2ND CLUTCH
I?C-44
Figure
7C-44 Second Clutch Orifice Valve
When the second clutch is being applied, the apply
pressure seats the ball and the feed is directed
through a single orifice. During the release of the
clutch, the ball is unseated and the clutch can ex-
haust at a faster rate through the two orifices.

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- 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- 95
12. Place suitable jack under transmission and
remove transmission support bolts.
13. Lower transmission enough to remove detent
cable and modulator vacuum line.
14. Remove speedometer cable.
15. Remove selector lever.
16. Mark flywheel and converter for reassembly in
same position, and remove converter to flywheel
bolts. See Figure 7C-106.17. Remove converter housing to engine bolts and
tiller tube.
18. Pry transmission loose from engine.
19. Keep rear of transmission lower than front to
prevent converter from falling and install converter
holding fixture J-21366. Lower transmission and
move to bench.
Installation. Opel 1900 and Manta1. Assemble transmission to suitable jack and raise
transmission into position. Rotate converter to per-
mit coupling of fly wheel and converter with original
relationship. Remove J-21366.
2. Install tiller tube and converter housing to engine
block bolts. Torque to 35 lb. ft. DO NOT over
torque.
3. Install flywheel to converter bolts. Torque to 30 lb.
ft.4. Install detent cable to transmission.
5. Connect oil cooler lines.
6. Install lower bolt on starter. Torque to 40 lb. ft.
7. Connect shift linkage to transmission.
8. Connect modulator line.
9. Connect speedometer cable.
10. Install transmission support.
11. Install drive shaft. Torque U-Bolts to 18 lb. ft.
12. Install flywheel cover pan. Torque to 15 lb. ft.
13. Install engine support brackets.
14. Reconnect exhaust system.15. Attach stabilizer supports and tighten stabilizer
bolts in lower control arms.
16. Lower car.
17. Install starter bolts. Torque to 40 lb. ft.
18. Reconnect battery.
19. Fill transmission with fluid as described in
Specifications. Check selector lever and detent cable
adjustment.
Removal GT1. Disconnect battery.
2. Remove dipstick.
3. Pull throttle control rod off ball pin.
4. Remove screws from fan shroud.
5. Raise car and provide support for front and rear.
6. Remove heat protection shield from right side to
make room for exhaust pipe removal.
Figure 7C-957. Detach exhaust pipe from manifold flange.
8. Unhook damper rings on front muffler and tail
pipe from brackets on body floor panel. Place ex-
haust pipe assembly onto rear axle. See Figure 7C-
96.9. Remove propeller shaft. Make sure that spring in
front universal joint does not get lost.

7C- 981973 OPEL SERVICE MANUAL
Figure 7C-105Figure
7C-106Installation GT
1. Assemble transmission to suitable jack and raise
into position. Rotate converter to permit coupling
with flywheel in original relationship. Remove hold-
ing fixture.
2. Install tiller tube and converter housing to engine
bolts. Torque to 35
lb.ft.3. Install flywheel to converter bolts. Torque to 30
lb.ft.4. Install detent cable.
5. Connect oil cooler lines.6. Install lower bolt on starter. Torque to 40 lb.ft.
7. Connect modulator line.
8. Connect speedometer cable.
9. Connect shift linkage.
10. Install transmission support.
11. Install drive shaft. Torque U-bolts to 18 lb.ft.
12. Install flywheel cover pan.
13. Reconnect exhaust system and heat shield.
14. Install engine support brackets.
15. Lower car,
16. Install starter bolts, Torque to 40
lb.ft.17.
C:onnect battery.
18. Fill transmission with fluid, as described in
Specifications. Check selector lever and detent cable
adjustment.
DISASSEMBLY, INSPECTION AND REASSEMBLY
Transmission Installation Into Holding FixtureI. Remove transmission tiller tube.
2. With transmission on cradle of portable jack,
remove converter assembly by pulling straight out.
Converter contains a large amount of oil.
3. Install holding fixture, J-8763-01, on transmission.
4. Install holding fixture and transmission into hold-
ing base tool J-3289-20 with bottom pan up. See
Figure
7C-107. Do not overtighten.
Figure
7C-107