1973 OPEL GT-R service

6G- 68 1973 OPEL SERVICE MANUAL
SPECIFICATIONS
TUNE-UP SPECIFICATIONS AND ADJUSTMENTS
Voltage Regulator
Voltage Regulator Setting in Volts at2500 Engine RPM. . . . . . . . . . . . . . . . . . . . . .14+.5
Ignition Coil
Ignition Coil Current Draw, Amperes at 12.5 Volts
Engine Stopped
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . \
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . \
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . \
. . . . . .3.8
EngineIdling. . . . . . . . . . . . . . . . . .._.....................................................................\
........................... 2.3
Total Advance (Centrifugal and Vacuum), Engine Degrees at 3600 Engine \
RPM......29-38
Centrifugal Advance, Engine Degrees and RPM
Start Advance, atRPM
........................................................................\
................ 1000-1200
Medium Advance, Degrees at RPM..............................................................7.5-15 at 1400
Maximum Advance, Degrees at RPM
..........................................................28-32 at 3600
Vacuum Advance, Engine Degrees and In. of Vacuum Start Advance..
........................................................................\
.................-5at2.9-4.1 In.
Maximum Advance..........................................................................\
........1-5at4.5-5.0In.
Vacuum Retard, Engine Degrees at Closed Throttle............................................................-5
Condenser Capacity in
MicroFarads........................................................................\
.......23-.32
Breaker Spring Tension in Ounces........................................................................\
......14 to 19
Breaker Point Gap in Inches
........................................................................\
......................,016
Dwell AngleinEngine Degrees........................................................................\
.......... 50+3
Firing
Order........................................................................\
............................................l-3-4-2
Spark Plug or Coil Cable,Max.Resistance in Ohms
..................................................
10,000
Spark Plugs
Make and Model Production........................................................................\
............AC42FS
Make andModel
-Replacement........................................................................\
..........AC42FS
If carbon fouling occurs, use
........................................................................\
............AC43FS
Spark Plug Torque in
Lb.Ft.........................................................................\
.........................30
Spark Plug Gap in Inches........................................................................\
..........................,030
Valve Lifter Adjustment
One full turn (clockwise) after zero clearance is obtained - refer to Valve Adjustment
Procedure
Ignition Timing
Align timing marks with distributor retard hose disconnected and plugged\

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- 41973 dPEL SERVICE MANUALConditionPossible CauseCorrectionHeat-blued driven plate
and pressure plate
assembly.
1. Improper pedal1. Replace only driven plate, and
adjustment.adjust clutch pedal and cable.
Grab and chatter with
oil present on clutch
assembly.1. Oil leak.1. Correct oil leakage, clean
pressure plate in solvent, replace
driven plate and adjust pedal lash.
MAINTENANCE AND ADJUSTMENTS
CLUTCH LASH ADJUSTMENT
GTPedal lash, free pedal travel must be adjusted occa-
sionally to compensate for normal wear of the clutch
facings. As the driven plate wears thinner, pedal lash
decreases. Adjust clutch pedal free travel only with
ball stud located on right side of clutch housing if
cable length is not to be changed. To adjust pedal
lash proceed as follows:
1. Loosen lock nut on ball stud end located to the
right of the transmission on the clutch housing. Posi-
tion ball stud so that the outer end protrudes 3/4
inches out of housing and finger tighten lock nut. See
Figures
7A-1 and 7A-6.
2. Adjust ball stud, pivoting clutch release fork, to
obtain 3/4 to
l-1/4 inches pedal lash, free pedal. See
Figure 7A-6.
Opel 1900 and MantaThe clutch actuation works without clutch pedal free
travel. A readjustment of the clutch is only required
if the indicator lamp at the instrument panel lights
up.In synchronism with the gradual wear of the clutch
linings the clutch pedal travels from its basic adjust-
ment position upwards,
ie., towards driver. If the
clutch lining wear has reached such an extent that
the clutch pedal rests against switch, the indicator
lamp at the instrument panel lights up.
This is an indication that the clutch pedal position
has to be corrected to ensure proper clutch operat-
ion.
To
&~sure proper clutch operation, observe the fol-
lowing adjustment instructions.. For all adjustment
dimensions, refer to Figure 7A-7.
1. If the parking brake is provided with an indicator
lamp, the parking brake has to be disengaged, other-wise the same indicator lamp as for the clutch lights
UP.2. Carry out adjustment only with ball stud on clutch
housing whereby the distance (Item 20, Figure 7A-7)
between clutch housing contacting surface and
clutch release lever has to be adjusted in the rear to
4
l/4 inches.
Clutch Control Cable Adjustment(Only on
Installation of a New Clutch Disc or
Bowden
Control Wire)
GT1. Adjust ball stud so that outer end protrudes ap-
proximately 3/4 inches out of clutch housing.
2. Adjust distance between release lever and clutch
housing face at eye for control cable to approxi-
mately 4
l/4 inches. See Figure 7A-6. Hold cable in
this position and place E-ring two grooves ahead of
washer on rubber grommet. Clutch pedal free travel
is now between 3/4 and 1
l/4 inches and clutch
release bearing has proper clearance from pressure
plate.
Opel 1900 and Manta1. Adjust ball stud on clutch housing to basic dimen-
sion of approximately 3/4 inch. With lower end ofbowden control wire unhooked, push clutch release
lever towards the front so that the clutch release
bearing rests against clutch spring. Now, adjust ball
stud so that the dimension (Item 20, Figure
7A-7)between clutch housing contacting surface and
clutch release lever amounts in the rear to 4
l/4
inches.2. Pull reattached bowden control wire out of dash
panel so that clutch pedal rests against switch (in-
dicator lamp lights up).
3. In this position, install lockwasher at upper con-
trol wire attachment three grooves towards the front,
thereby completing control wire adjustment.

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.

7A- 81973 OPEL SERVICE MANUAL\\“\314”TO ,l
17
16
1.E-RING12. CLUTCH PEDAL FREE TRAVEL-
2.WASHER3/4” TO 1 l/4”
3.RUBBER GROMMET13. RETURN SPRING
4.WASHER14. RELEASE LEVER
5.SLEEVE15. RUBBER BELLOWS
6.DASH PANEL16. BALL STUD LOCK NUT
7. BOWDEN CONTROL CABLE17. CLUTCH HOUSING
8.BRACKET18. BALL STUD
9. WASHER, HAIRPIN CLIP19. BOWDEN CONTROL CABLE
10.RUBBER STOP20. DISTANCE BETWEEN RELEASE
11.CLUTCH PEDALLEVER AND CLUTCH HOUSING
7A.6\
Figure
7A-6 Clutch Pedal Lash - GT Model

7A- 101973 OPEL SERVICE MANUAL
Arrangement Of Clutch
1 Clutch release lever14 Clutch ossy. bolt, lockwasher
2 Slot in lever for control cable boll15 Hollow space under felt ring filled
endwith molybdenum disulfide paste
3Assembly marks
4Clutch assembly
5Flywheel
6 Flywheel ring gear
7Thrust pin
8Retaining spring
9Crankshaft
10 Clutch gear pilot bushing
11Oil seal
12Flywheel bolt
13Clutch housing
16 Felt ring
17 Clutch release bearing
18 Clutch gear ball beorirq
19 Clutch gear
20 Snap ring
21 Paper gasket
22 Clutch gear oil seal
23 Clutch release bearing sleeve
24 Clutch disc, long end of hub facing
forward.
?A-8Figure
7A-8 Arrangement of Clutch

7B- 121973 OPEL SERVICE MANUAL
MANUAL TRANSMISSION
CONTENTS
Subject
DESCRIPTION AND OPERATION:
Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Power
Flow. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .DIAGNOSIS: (Not Applicable)
MAINTENANCE AND ADJUSTMENTS:
Adjusting
ReverseGearshiftBlocker. . . . . . . . . . . . . . . . . . . . . . . . . .Shift Lever Installation
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ServicingGearshift
Lever. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .MAJOR REPAIR:
Transmission
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Installation
ofTransmission. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Removing and Installing
Speed0 Driven Gear
(Transmission
Removed). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ReplacingBushinginSelectorLever. . . . . . . . . . . . . . . . . . . . . . . . . .Transmission
Disassembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Transmission
Reassembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .SPECIFICATIONS:
Specifications ..,....._....,......,.....,......,.,.....,,.,..,......,.,....,........
Page No.
78-12
7B-13
78-1978-l
9
7B-19
78-22
78-22
78-23
78-23
78-23
78-28
78-33

7B- 141973 OPEL SERVICE MANUAL
POWER FLOW - 1st SPEED
MAIN DRIVE GEAR (INPUT)
COUNTERSHAFT GEAR UNIT 1st SPEED GEAR
1 st SPEED GEAR
1st AND 2nd GEAR SLIDING GEAR1st AND 2nd SPEED SLIDING GEAR GUIDE UNITCOUNTERSHAFT GEAR
UI‘!IT DRIVE GEAR1st SPEED GEAR1st AND 2nd GEAR SLIDING GEAR
,st AND 2nd SPEED SLIDING GEAR GUIDE UN1MAINSHAFT (OUTPUT)
70-2Figure 78.2
First SpeedAfter synchronizing the speeds of the mainshaft and
the 1st speed gear, the 1st and 2nd gear sliding gear
shifts to the rear of the transmission and locks the 1st
speed gear to the mainshaft through the 1st and 2nd
speed sliding gear guide unit. This 1st and 2nd speed
sliding gear guide unit is internally splined to the 1st
and 2nd gear sliding gear and is
exl~ernally splined to
the mainshaft. Both the 3rd speed gear and the 2nd
speed gear are idling. The reverse idler gear is not
engaged with any gear and, therefore, it is idle.
With a 1st speed gear ratio of
3.428:1, the main drive
gear (input) must turn 3.428 revolutions for every
one revolution of the main shaft (output).
IT