engine OPEL GT-R 1973 Owner's Guide

i
1 D- 301973 OPEL SERVICE MANUAL
6. Make sure all electrical accessories are turned (lff.
Start engine with battery post adapter switch closed;
open switch as soon as engine
iS: started.
7. Adjust engine speed to 2500 RPM.
8. Turn tester control knob to “LOAD” position
aid
adjust knob to obtain highest possible ammeter r&d-
ing. Output must be 30 amperes minimum. If
outcut
is okay, proceed to voltage regulator test below. j
/.9. If output is low, defect may be in alternator or m
regulator. To eliminate regulator, supply field &-
rent direct to cause full alternat,or output. Unplug
three-way connector from regulator and plug in a
jumper between the red and black leads. See Figure
lD-5. Retest as described in Steps 7 and 8. If output
is still low, generator is faulty and must be
remov&d.
301D5 :
Figure lD-5 Alternator Ouiput Check I
10. If output (using field jumper) is now okay, defect
is in the regulator or wiring harness. Check all wiring
connections. If all wiring is okay, try
replac/~g
regulator; if output now tests okay (without
uslpg
field jumper), you have found the trouble. Always
follow-up with a voltage regulator test.
Test and Adjust Voltage Regulator Setting
1. Always test alternator output first, as describedlin
subparagraph a above. Leave all test
instrumeqts
connected, but make sure field
jumper is removed; if
used.
2. With engine speed at 2500 RPM, turn tester con-
trol
knob to “l/4 OHM” position. Make sure ill
electrical accessories are turned off. After volt&e
reading stabilizes, any reading between 13.5 and 14.5
volts is okay.
3. If voltage reading is out of limits, remove regulator cover and adjust voltage regulator armature spring
tension to obtain a middle reading of 14.0 volts. If
reading fluctuates, voltage contacts are dirty.
4. Replace regulator cover and recheck voltage set- ting. A steady voltage reading between 13.5 and 14.5
volts means voltage regulator is okay.
5. Adjust engine speed to specified idle. Reseal volt-
age regulator cover carefully, using electrical tape.
MAJOR REPAIR
ALTERNATOR OVERHAUL
Always disconnect battery ground cable before mak-
ing any electrical repairs.
Alternator Removal
1. Disconnect battery ground strap.
2. Unplug wiring connector from alternator. 3. Disconnect battery lead from alternator.
4. Remove adjusting brace bolt, lockwasher, plain
washer and nut.
5. Loosen pivot bolt. Push alternator inward and
remove belt from pulley.
6. Drop alternator down and remove pivot bolt, nut,
lockwasher and plain washer.
7. Remove alternator.
Figure 1D-6 Removing Alternator Pulley

CHARGING SYSTEMlD- 35
’Figure lD-25 Installing Diode
I
7. Instail rotor together with drive end frame intostator and assemble generator in reverse order ofdisasse+bly. Make sure marks made during disas-
sembly
+-ire aligned.
8. Insta!l pulley and fan. Tighten nut to 30 lb.ft.
9. Test benerator on test bench, if available. If not,
install alternator on car and test.
Alternator Installation
1. Hold /alternator in position and install pivot bolt,
plain washer, lockwasher and nut finger tight.
2. Install alternator belt.
3. Install adjusting brace bolt, lockwasher, plain
washer and nut finger tight.
4.
Posit& a belt tension gage such as Gage J- 23600Figure 1 D-26 Alternator Installation
on belt. Pull alternator outward until gage reads 45
Ibs., then tighten adjusting brace bolt.
5. Tighten alternator pivot bolt.
6. Connect battery lead to alternator.
7. Plug three-way wiring connector into alternator
and engage safety catch.8. Connect battery ground strap.SPECkICATIONS
ALTERNATOR
35, AMPAlternatorNumberRated
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Kl 14V35AZOOutputinVolts
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14ContinuousRatedOutputinAmperes
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35Test Output in Amperes at
2000 Engine RPM. . . . . . . . ..__.._...........................................23 Min.RksistanceofFieldCoilinOhms
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-4.4Resistanceof StatorWindingsinOhms
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26-29AlternatorPulleyNutTorqueinLb.Ft.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
BfltTensioninPounds. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
REGULATORRegulatorNumber
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ADl/14V
Regulator Setting in Volts at 2500 Engine R.P.M.
. . . . . . . . . . ..___................................14 f .5

LIGHTING SYSTEMSlF-472. Install switch in panel.
3. Replace instrument cluster cover.
EXTERIOR LIGHTSModels 51-53-54
Headlamp Sealed Beam Unit Removal1. Remove two screws on headlight ring.
2. Remove four screws holding headlight retainer to
body. See Figure lF-3.
Figure 1 F-l Removing Headlight Switch
I
3.
Rep& two (2) plugs over screws and replace
heater control knobs.
FOG LIGHT OR HEATED REAR GLASS SWITCHRemoval I
1. Removd instrument cluster cover. See Section H.
I
2. Press
ddwn retaining clip and pull switch out. See
Figure lF-2.
Figure 1 F-3 - Removing Headlight Retainer
- Models
51-53-54
3. Disconnect wiring connectors,
4. Remove headlight from inside engine compart-
ment.
Figure 1Fi2 - Removal of Fog Light or Heated Rear
Glass Switch
3. Removelwires from switch.
Installation/
1. Connect;wire to switch,
Installation1. Plug in wiring connector on sealed beam and re-
place four (4) headlight retaining screws.
2. Replace headlight ring.
Models 57-57R
Removal
I. Disconnect wiring connector.
2. Remove four screws holding headlight retainer
from inside engine compartment.

1~- 48 1973 OPEL SERVICE: MANUAL/
3. Disassemble headlight assembly from retaini+g
ring. See Figure lF-4.
i
tFigure 1 F-4
- Headlight Assembly - Models 57.57R
Installation1. Assemble headlight to retaining rings.;
2. Install to body from inside engine compartmept
with four (4) screws.
3. Connect wiring harness.
Parking Light Housing or Lens Removal1. Remove two screws holding lamp lens.:
2. Remove two screws holding housing. See FigurelF- 5.
Figure lF-5 Remove Parking Light Housing
3. Disconnect wiring harness.1. Apply sealer to housing
2. Connect wiring harness.
3. Replace housing in body with two (2) retaining
screws.4. Replace lamp lens.
REAR STOP, TAIL, DIRECTIONAL SIGNAL, OR
BACK-UP LAMP HOUSINGMod&
J-I-53
Removal1. In luggage compartment, unscrew housing attach-
ing nuts. See Figure lF-6.
Figure lF-6 Tail Light Housing Attaching Nuts
Models 5 1-53
Figure lF-7
- Removing Tgil Light Lens - Models
51.53

,I
IINSTRUMENT PANEL
lH- 57
/
/SubjectPage No. INSTRUMENT PANEL
CONTENTS
DESCRIPTION AND OPERATION:
Instrument Panel
- Opel 1900 - Manta. . . . . . . . . . . . . . . . . . . . . .Instrument
Panel-GT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .DIAGNOSIS:
MAINTENANCE AND ADJUSTMENTS:
MAJOR REPAIR:
Instrument Cluster Housing
- Opel 1900 - Manta . .
Windshield Wiper Switch
. , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .InstrumentCluster
Bulbs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .InstrumentCluster
Housing-GT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Combined Switch Assemblies
. . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .CigarLighter
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .SPECIFICATIONS: (Not Applicable)
I H-57
1H-58
1H-59
1H-61
lH-61
1H-61
1H-63
1H-64
DESCF(lPTlON AND OPERATION2. The fog light toggle switch lower half is pushed in.INSTRUFENT PANEL (OPEL 1900. MANTA)
Headligl$ Switch
3. The parking lights and/or low beam headlights are
on.The thr& position light switch controls the head-
lights, @lights, parking lights, side marker lights,
license
plate light and instrument panel lights and is
located
4t the lower left on the instrument panel.
With thk switch knob pulled outward to the first
stop,
thi parking lights, side marker lights, license
plate
ligiit and instrument panel lights will light. Theinstrumdnt panel lights can be turned off by turning
the
lightSwitch knob counterclockwise past the first
detent. IThe fog lights are automatically turned off if the
ignition switch is on and the headlights are on high
beam.
Windshield Wiper Switch
The windshield wiper switch is located on the instru-ment panel to the right of the headlight switch.
By pull&g the lightswitch knob out all the way, the
headlights will also be turned on.
IBy pushing the lower half of this switch in to the first
stop, the wipers will operate at slow speed. By push-ing in to the second stop, the wipers will operate at
fast speed.
Fog
Ligh) Switch (Rallye)The fog
iight toggle switch is located in the instru-
ment cluster to the left of the temperature and fuel
gauge
cl+ster. The fog lights can be turned off at any
time by
t,he toggle switch, but can only be turned on
when: ,
Electrically Heated Rear Window Switch (If
Equipped)The heated rear
wind&v switch is located in the
instrument panel to the right of the clock opening.
1. The ignition switch is on or the engine running.
ITo operate (only possible with the engine running),
push in on the lower half of the switch. When the
rear window is being heated, the switch will
belighted.

/
I
IINSTRUMENT PANELlH- 59
Figure 1 H-2
- GT Instrument and Switch Arrangement
The Wihdshield Wipers have two-speed operation.
By pushing the lower half of the switch inward to the
first stop, the wipers will operate at half speed and
by deprbssing to the second stop will provide full
speed oieration. When the switch is returned to the
off posit/on, the wiper blades automatically return to
their park position.
I
The El standarFf whether or not the vehicle is equipped with
this optlpn. The engine must be running before
suffi-cient current can be generated to energize this circuit
even th6ugh the switch is depressed to the “ON”
position! When the window is being heated, a warm-
ing light’on the instrument panel will glow. This light
is locate? below the left ventilation inlet.
The
Heiter Blower Switch is a three position switch.
By depressing the lower half of the switch to the first
stop,
th& blower will operate at low speed. Whendepressdd to the second stop, the blower will operate
at high ipeed.
Four Way Hezrerd Warning Flasher SwitchThe
hazard warning flasher switch is located below
the heater controls in the center console. By
depress-ing the lower half of the switch, all four turn- signal
lamps flash at the same time. Although this system
makes use of the regulat turn signal system, it has a
separate feed wire to the switch which allows for its
operation even with the ignition switch and doors
locked. No vehicle should be driven with this system
in operation because of its universal meaning “This
Vehicle Is Not Moving”. To turn the system off,
simply depress the upper half of the switch.
MAJOR REPAIR
Removal of Instrument Cluster Housing Assembly.Opel 1900 Manta
Before starting any instrument panel repair, always
disconnect battery ground cable first.
I

I
GAUGES1 I- 67I
I Condition
Car
&s out of gas with
gauge indicating fuel in
tank. 1
I
I
I
I
IPossible Cause
1. Tank unit misadjusted
2. Defective voltage
stabilizer.Correction
1. Follow corrective action as
stated above (obtain empty
reading on dash)
1. See corrective action above.
Temperature gauge not1. Loose dash gauge1. See corrective action above.
Iattaching nut.
I
I
I2. Defective temperature1. Install 40 ohm resistor
Isending unitbetween temperature sneding
Iunit and ground (disconnect
I
from unit). If dash unit reads
I
full scale, replace temperature
Isending unit.
I
I
I3. Open wiring.1. Follow corrective action as
Istated above (connector socket
Iwith blue wire).Tempkrature gauge indicates
hot when engine temperature1. Incorrect temperature1. Check for correct sending unit
sending unit
normal.(white porcelain) replace if
incorrect.
2. i>efective temperaturesending unit.1. See corrective action above.
3. Dkfective voltage
stabilizer.
1. See Corrective action above.
GAS
GdUGE TROUBLE DIAGNOSIS - GT4. Disconnect the tank unit lead wire (light blue with
black tracer) from the tank unit.
An inoperative gas gauge reading can normally be
found to result from a poor grounding condition
within the circuit. Using the procedure as outlined
below may lead to the correction of the inoperative
reading without replacement of either the tank unit
or the
dph unit.5. Connect ihe stock tank unit; ground unit, and
operate manually.
6. If the dash unit shows a correct reading, then
replacement of the tank unit is required as the cor-
rection.
1. Makelcertain the gas tank (ground) strap is prop-
erly secured.A correct reading will be one which resembles the
movement of the manually-operated tank unit.
2. Make’certain the ground wire (brown in color) for
gasoline/ and temperature gauges is properly con-
nected tb the windshield wiper motor and is secured.
(This
gl?ound wire is also common for the heater
blower
etor.)7. If the dash unit does not show a correct reading,
then its replacement is necessary.
If the adove procedure does not produce a satisfac-
tory gaube reading, an attempt to isolate the defec-
tive
par<, i.e. tank or dash unit should be made.
3. Rem&e a tank unit from parts stock.MAJOR
AEPAIR
OPEL 1900. MANTA
Removing Voltage Stabilizer1. Remove instrument cluster housing assembly.

3A- 21973 OPEL SERVICE MANUAL
FRONT SUSPENSION
CONTENTS
Subject
DESCRIPTION AND OPERATION:SuspensionDescription. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .DIAGNOSIS: (Not Applicable)
MAINTENANCE AND ADJUSTMENTS:
FrontWheel
BearingAdjustments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .MAJOR REPAIR:
Removal and Installation of Front Suspension . . . . . . . .Upper Ball Joint Removal and Installation
. . . . . . . . . . . . . .Lower Ball Joint Removal and
Installation
. . . . . . . . . . . . . .Upper Control Arm
Removal andInstallation
. . . . . . . . . .Lower Control Arm Removal and Installation
. . . . . . . .Steering
Knuckle
RemovalandInstallation. . . . . . . . . . . . . .Shock Absorber
RemovalandInstallation. . . . . . . . . . . . . . . .Front Spring Removal and Installation
. . . . . . . . . . . . . . . . . . . . . .SPECIFICATIONS:Page No.
3A- 2
3A- 4
3A- 4
3A- 7
3A- 73A-103A-113A-133A-153A-15
Bolt Torque and Front End Alignment Specifications
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3A-18
DESCRIPTION AND OPERATION
SUSPENSION DESCRIPTION
GTThe GT uses a maintenance-free independent front
wheel suspension and features unequal length con-
trol arms and a transverse three-leaf spring. The en-
tire front suspension is attached to the front cross
member and can be removed as a unit if so desired.
The engines installed in the GT are not supported by
mounting brackets but rest on a separate cross mem-
ber. The front suspension cross member is reinforced
in the area of the attachment to the frame. A one-
part damper plate is installed between cross member
and frame.
Ball joints are employed in the conventional manner
to provide pivoting joints between the control arms
and steering knuckles. Upward movement of the
control arms is limited by two large rubber bumpers
attached to the cross member.Road shock is dampened by the double direct acting
shock absorbers and a transverse double or triple
steel band spring. In addition, the shock absorber
limits downward travel of the control arms.
All moving parts, including ball joints, have no need
for lubrication as they have been pre-lubricated for
the life of the vehicle.
For distinguishing the individual front suspension
cross members,.a red label with black letters is stuck
onto the front side of the shock absorber support. See
Figure 3A-3.
Opel 1900. Manta
The front wheel suspension has coil springs and con-
trol arms of different length.
The stabilizer is designed to act as a tie strut. The end
is supported in a rubber bushing which is located in
a piece of tubing welded into the longer control arm.
To minimize brake torque, the horizontal shafts of

3A- 41973 OPEL SERVICE MANUAL
The two cross-members to body supports are at-
tached to the horizontal part of the cross-member
with two bolts. The oufererbolt serves simultaneously
as support for the lower control arm. As the bolt is
inserted from the front, the cross-member to body
support can be removed without the lower control
arm. The inner bolt attaches simultaneously to the
steering.
The stabilizer is U-shaped and supported in rubber
bushings in the two cross-members to body supports.
The complete front suspension is attached to the
underbody in four places.
The engine damper blocks are bolted to the inside of
the inclined parts of the cross-member.
The front wheel bearings are roller bearings.
All front suspension joints are maintenance-free.
MAINTENANCE AND ADJUSTMENTSFRONT WHEEL BEARING ADJUSTMENT
1. If wheel has not previously been removed from the
car, remove grease cap, cotter pin, and spindle nut.
Discard cotter pin.
2. Torque spindle nut to 18
lb.ft. while rotating
wheel. This will allow the bearings to settle.
3. Back offspindle nut
l/4 turn. If slot and cotter pin
hole are staggered, further back off nut
l/l2 turn,
but do not tighten, until next slot in nut is in align-
ment with hole in spindle. Install new cotter pin. A
properly adjusted wheel bearing has a small amount
of end play and a loose nut when adjusted in the
above manner.
MAJOR REPAIRREMOVAL AND INSTALLATION OF FRONT
SUSPENSION
(COMPLETE ASSEMBLY)
Removal GT1. Prior to raising front end of car, apply parking
brake and block rear wheels.
2. Raise front end of car with a jack. It is recom-
mended that a wood block be placed between thejack and the front cross member to prevent damage
to the cross member.
3. Support front end of car by placing floor standsunde:r jacking brackets.
4. Support engine-transmission assembly in upper-
most position with jack stand at rear of engine, or an
alternate method would be to use Engine Holding
Fixture, Tool J-23375. See Figure 3A-5.
Install tool by removing upper kngine mount nut and
installing fixture. Replace nut and tighten. The en-
gine will now be supported by the tool between the
frame rails.
Figure
3A-5 Engine Holding Fixture Installed
5. Loosen steering mast at the lower universal joint
and take out clamp bolt. Loosen clamp at the upper
universal joint and lift steering mast upwards until it
is free at the lower universal joint. See Figure
3A-6.6. Disconnect brake lines at brake hose.
7. Disconnect shock absorber at upper mounting. It
is necessary to remove air cleaner. See Figure
3A-24.8. Disconnect engine mounts at cross member.
9. Remove front suspension cross member attaching
nuts and lower the cross member.
Removal Opel 1900 - Manta1. Prior to raising front end of car, apply parking
brake and block rear wheels.

FRONT SUSPENSION3A- 5
Figure 3A-6 GT Steering Mast Joint
2. Install Hooks J-23697 before jacking up car to
assure proper loading of suspension bushings and
mounts. See Figure
3A-7.3. Raise front of vehicle and support with stands.
4. Remove front wheels.
5. Remove guard plate. See Figure
3A-8,6. Remove brake line retainers on both sides. The
brake system remains closed. Unscrew brake calipersand suspend them in wheel house.Figure
3A-9 Removing Guard Plate
7. Suspend engine with a suitable engine lifter, simi-
lar to the one shown in Figure
3A-9.8. Unscrew lower steering mast clamp bolt out of
pinion flange. See Figure
3A- 10.
9. Unscrew front left and right engine mount from
damper block.
10. On top and in the rear, unscrew front suspensionFigure
3A-7 Installing Hooks J-23697Figure 3A-9 Suitable Engine Liftel