light OPEL GT-R 1973 User Guide

lB- 14 1973 OPEL SERVICE MANUAL !
6. Remove shift lever shaft and: lift armature aid
shift lever assembly.
7. Drive back retaining ring on armature shaft. See
Figure
lB-5.
8. Take the lock ring, retaining ring, and
over&-
ning clutch and pinion off armature shaft. Cheqk
groove in shaft for burrs and remove with a soft tile.
Cleaning and Inspecting Parts
1. Clean and check all parts. Replace defective parts.
2. Turn down worn or burnt
cominutator on a good
precision lathe. Use a spindle
speed between 2,000
and 3,000 RPM. See Figure
lB-6. When turning
down commutator, adjust cutting depth of tool
so
that no more pits exist after this:operation. Do not
remove any more material than necessary, however,
because if commutator diameter
is less than 1 15/32
inches, armature must be replaced.
30166
Figure 1B-6 Turning Down Commutator
3. Undercut mica approximately ,020 below com-
mutator surface. Finish and thoroughly clean
corn-
mutator.
I
4. Check armature for short circuit on a
growler.
5. With a test lamp, check armature for ground.
Test
lamp must not light up. See Figure
IB-7.
Figure 1B-7 Testing Armature for Grounds
j
6. Check armature for an open circuit on a growler.
Considerable variation in readings between in-
dividual commutator bars would indicate an open
circuit.
7. Visually check
field coils. Replace burnt or
scorched
field coils.
8. With a test lamp, check
field coils for ground. See
Figure
IB-8. Test lamp must not light up. Replzice
grounded field coil.
Figure lB-8 Checking Field Coils for Ground
Replacing Field Coils
1. Mark locations of pole shoes to avoid incorrect
installation.
Figure 1B-9 Removing Pole Shoes

STARTING SYSTEMlS- 15
2. Unscrew the four (4) pole shoe attaching bolts and
take
field coils out of field frame. See Figure lB-9.
3. To ensure proper installation of the pole shoes,
align shoes exactly parallel with the armature shaft
prior to tightening attaching bolts.
Checking
a’nd Replacing Brushes
1. Check
b&h positive brush holders for ground. See
Figure
lB-,lO. Test lamp must not light up.
Figure 1g-10 Checking Positive Brush Holder forGrounds
2. Check brushes. Replace brushes, if worn down to
.28 inches or less. Always replace all four (4)
brushes.
3. To replace positive brushes, cut off wires at the
connecting strap of the field coil. Clean soldered joint
and solder stranded wire of new brushes. Hold wire
with
flatnose pliers so that no tin enters wire strands.
4. On replacement of the negative brushes, the com-
plete brush holder with the welded brush has to be
replaced. 5. Shear off rivet head with a chisel and drive rivet
out. See Figure
lB-11.
6. A tool to replace the negative brush holder and
rivet can be made up out of
l/4 inch steel. See Figure
Figure 18.12 Negative Brush Holder Installation Tool
7. Place new brush holder and new rivet on installa-
tion tool and insert rivet into bore of
field frame. See
Figure
lB-13.
Figure 1B-11 Removing Rivet Figure 18-13
Brush Holder and Rivet Installed on Tool

1 C- 18 1973 OPEL SERVICE MANUAL
IGNITIPN SYSTEM
CbNTENTS
Subject
DESCRIPTION AND OPERATION: Ignition System ..................................................................
Ignition
Switc,h....................................................................
Ignition Coil
..........................................................................\
Distributor
............................I...............................................
DIAGNOSIS: (Not Available)
MAINTENANCE AND ADJUSTMENTS: Contact PointReplacement ............................................
Dwell Angle Adjustment :
................................................
Ignition Timing Adjustment ..........................................
Ignition Wire Inspection :
..................................................
Check Ignition Output ......................................................
Check Distributor
..............................................................
Check Spark Plugs
............................................................
MAJOR REPAIR: Distributor Removal ..........................................................
Disassembly ........................
I...............................................
Reassembly
..........................I...............................................
Distributor Installation
....................................................
SPECIFICATIONS: /
Ignition
Coil ..........................................................................
Distributor
....‘........................i...............................................
Spark Plugs ........................................................................\
..
DESCRIPTION AND OPERATION
INGITION SYSTEM
The ignition system basically consists of an ignitipn
switch, ignition coil, distributor, battery and related
wiring. The ignition switch is located in the steering
column, the ignition coil is located left front inner fender
skirt and the distributor is located at the left
front of the engine.
IGNITION SWITCH
The combined ignition switch and steering lock ian
be switched to any one of the below listed positions.
Insert key with notch pointing upward.
Page No.
lC-18
lC-18
lC-19
lC-19
1 c-20
1 c-20
1 c-20
lC-21 r
lC-21
1 c-22
1 c-22
1 r-23
1 C-23
1 c-24
1 C-25
1 C-26
1 C-26
1 C-26
(Fully counterclockwise) Lock position. Ignition
locked, steering locked, only with key removed.
Electrical circuits disconnected except to main light-
ing switch and dome lamp. The
key can be removed.
0- (First position clockwise from lock) Garage posi-
tion. ‘The key and lock assembly must be pushed “in”
to reach this position from lock. The steering is un-
locked and the ignition is off. The electrical circuits
are the same as in lock position. The key cannot be withdrawn.
l- [Chposition.) All electrical circuits controlled by
ignition switch are completed through the switch.
The key cannot
be removed while switch is in drive
position.

I
ilC- 201973 OPEL SERVICE MANUAL
There is also a plastic hood slipped over the distrivu-tar cap with an outlet for the ignition cables as an
added protection against moisture from the outside.
See Figure lC-2.
Figure lC-2 Ignition Distributor With Hood Installed
MAINTENANCE AND ADJUSTMENTS
CONTACT POINT REPLACEMENT
Removing Contact Points1. Remove contact support lock
,screw and remqve
contact point support. If condenser is to be replaced,
it will be necessary to replace condenser and
1eads;asan assembly.
Installing Contact Points1. Lightly lubricate distributor cam with high tein-perature cam and ball bearing lubricant. Excessive
lubricant will throw off into contact points.
:
,
2. Position support on breaker plate and install lock
screw leaving slightly loose for later adjustment..
3. Plug breaker arm wire in.
4. Adjust breaker point gap to ,016”.
/
DWELL ANGLE ADJUSTMENT
1. Connect dwell meter.
2. Remove distributor cap. Remove rotor. Loosen
breaker point set screw approximately
l/8 turn.
3. Insert screwdriver in notch of stationary breaker
point. Observe dwell meter while cranking engine.
Twist screwdriver as required to obtain a reading of
50 degrees plus or minus 3 degrees.4. Tighten breaker point set screw, then recheck
dwell.
5. Install rotor and cap.~Start engine and recheck
dwell. It is important that dwell be rechecked, as
instal~lation of rotor and cap will sometimes change
the dwell angle.
IGNITION TIMING ADJUSTMENT
Preliminary Timing (Engine Won’t Run)To time the ignition on any engine which will run,
use subparagraph b only. However, if the timing of
an engine is completely off, the following procedure
must first be used to get the engine to run.
1. With rocker arm cover removed, rotate crankshaft
in a clockwise direction until both valves for No. 1
cylinder are closed and the timing marks line-up.
(Valves are completely closed if rocker arms can be
“rocked” slightly.)
2. Install distributor in engine so that vacuum ad-
vance unit is in original position and notch in dis-
tributor rotor lines-up with notch in housing. See
Figure lC-3. If distributor does not seat in engine
block., turn distributor shaft so that rotor points
about 20 degrees clockwise from distributor timing
notch
(see Figure lC-18), then press lightly on dis-
tributor housing while cranking engine with starter.
After oil pump tang snaps into slot in distributor
shaft, start timing again from Step 1, leaving dis-
tributor installed.
Figure lC-3 Rotor Position for Filing No. 1 Cyliqder
3. Install distributor clamp and bolt, leaving bolt just
loose enough to permit movement of distributor. In-
stall distributor primary wire.L

IGNITION SYSTEMlC-214. Rota&distributor counterclockwise slightly until
contact pbints just start to open. This must be done
very carefully or engine will not start.
5. Install distributor cap. Make sure spark plug wires
are correctly installed in distributor cap, through clip
and on spark plugs.
Finish TimingIContact boint gap
(.016” at widest gap) or dwell 50
degrees plus or minus 3 degrees should always be
checked before adjusting ignition timing.
1. Connekt timing light to No. 1 spark plug.
2. Disconnect and plug vacuum advance unit and
retard u$it hoses.
3. Connect a tachometer from distributor side of coil
to
groun$l.4. Start dngine. Set idle speed to 900 RPM.
5. Rotate distributor as necessary to align timing
marks. T;ming mark is a steel ball embedded in the
flywheel and a pointer in a window in the right fly-
wheel housing. See Figure lC-4.:Figure lC-4 Ignition Timing Marks
6.
Tightq clamp bolt securely and recheck timing
mark ahgnment.
7. Reconnect vacuum hoses and adjust engine idle
speed
an: mixture.
IGNlTlOFj WIRE INSPECTION
1. The c$il and spark plug wires are of a specialresistance type. These secondary ignition wires
reduce television and radio interference.
2. Wipe ignition wires with a cloth moistened with
solvent and wipe dry. Bend wires to check for brittle,
cracked or swollen insulation. Defective insulation
will permit missing or cross-firing of spark plugs,
therefore any defective wires must be replaced.
3. If wire insulation is in good condition, clean any
terminals that are corroded and replace any termi-
nals that are broken or damaged. Terminals must tit
tight on spark plugs and in distributor cap.
4. Replace any hardened, cracked or loose cap nip-
ples or spark plug boots.
5. Check resistance of each wire from contact inside
distributor cap to spark plug or coil terminal. Re-
place any wire having over 10,000 ohms resistance
reading. See Figure lC-5.
Figure fC-5 Checking Ignition Wire Resistance
CHECK IGNITION OUTPUT
1. Disconnect secondary coil ivire so that engine will
not start. Connect a voltmeter from the battery side
of the coil primary to ground and check voltage
while engine is cranking. Reading should be 10 volts
or more. Low reading could be caused by a defective
battery, a discharged battery, high starter current
draw, a bad connection in the starter circuit or a bad
connection in the primary ignition circuit.
2. Connect an oscilloscope according to manufac-
turer’s instructions. Disconnect coil wire. Crank en-
gine and read coil output voltage. Reading should
exceed 20 KV (20,000 volts).

lC- 22 1973 OPEL SERVICE MANUAL j
3. Start engine and disconnect a wire from a spark
plug. Read output voltage of disconnected spark
plug circuit. Reading should exceed 20 KV
(20,poO
volts).I
CHECK DISTRIBUTOR
!1. Clean distributor cap and inspect it for cracks or
tracking. Inspect inner segments for erosion and
outer sockets for corrosion.
2. Clean and inspect ignition wires. Make sure resist-
ance of each wire is less than 10,000 ohms. Replace
any defective spark plug boots or distributor
capnipples. See paragraph lC-12.
3. Inspect breaker points and replace if necessary.
Adjust breaker point gap to
,016 inch with rubbing
block on peak of cam lobe or check dwell and adjust
if not 50 degrees plus or minus 3 degrees. 4. Check
dwell variation by reading dwell at idle and at 3000
RPM. Dwell must not vary more than 3 degrees.
Excessive variation means distributor shaft, cam or
breaker plate are worn or damaged--overhaul dis-
tributor and replace defective parts.
5. Check distributor condenser for a minimum series
resistance and insulation leakage. Check for a
capacity between
.15 and .20 microfarads.
6. Check total advance (centrifugal and vacuum) at
2500 engine RPM using a timing light having a dial
for reading advance.
(a) The timing marks are aligned with both the
vacuum advance and the vacuum retard hoses dis-
connected and plugged.
Engine idle should be 900 RPM.
(b) Reconnect vacuum hoses. Run engine at
3600RPM and adjust knob until timing marks are
aligned. Read advance on dial. Maximum centrifugal
advance should be between 28-32 degrees.
7. If total advance is out of specifications, check
centrifugal advance only, at
2500 RPM. Discon+ectand plug all vacuum hoses. Maximum vacuum ad-
vance should be l-5 degrees at 4.5-5.0 in. hg.
8. Replace centrifugal or vacuum advance parts as
required to bring distributor total advance within
specifications.
9. Check operation of vacuum retard unit (rear unit)
by first making sure timing marks are aligned with
vacuum hoses disconnected and at slow idle (700
RPM). Then connect vacuum hose to vacuum retard
unit (rear unit). Timing ball should move in a retard
direction (upward).
CHEICK SPARK PLUGS1. Remove spark plugs. If electrodes are badly worn,
discard plugs. If inner or outer porcelain is cracked
or broken, discard plugs.
2. Note color and general appearance of inner end of
spark plug. Brown to grayish
- tan deposits and slight
electrode wear indicate correct spark plug heat
range. Plugs having this appearance may be cleaned,
regapped, tested and reinstalled.
3. Clean spark plugs in a sand blast type cleaner.
Clean only enough to remove deposits, not enough to
wear away porcelain. If deposits are too hard to
remove or if porcelain is glazed, discard plugs.
4. After cleaning spark plugs, clean tiring surfaces of
electrodes with a line file.
5. Test cleaned spark plugs on a pressure tester by
comparing spark of the used plugs with that of a new
plug. Install tested plugs, using new gaskets.
6. If removed spark plugs have excessive carbon foul-
ing and if the car will be driven mostly at low speeds
in city driving, it is advisable to replace plugs with
a hotter plug, AC43FS.
7. If removed plugs show rapid electrode wear or
inner porcelain breakage at low mileage. Check for
a vacuum leak such as a poor manifold to head fit.
8.
Clap spark plugs carefully (new or cleaned) using
a
,030 round wire feeler gage.IC6
Figure lC-6 Distributor Installation

1 D- 32 1973 OPEL SERVICE MANUAL
12. Unsolder brushes, if they are worn to a length of
3/8 inch or less. Solder new brushes in place. To do
this, hold connecting wire in flat-nosed pliers to
pre:
vent
solder from flowing between wire strands, oth-
erwise the wire strands will become rigid and the
brushes unserviceable. See Figure
lD-15.
Figure 1D-12 Disconnecting Brush Connector
Figure 1 D-l 5 Soldering New Brushes
Note brush wire installation of correct assembly. See
Figwe lD- 16.
Figure 60.13 Removing Biush Holder
9. Unsolder diode connections and stator winding
ends. Clamp pliers on wire to transfer heat away
from diodes. Unsolder quickly using a very hot sol-
dering iron, as the diodes are very sensitive to heat.
See Figure
lD-14.
Figure 1 D-l 6 Brush Wire Installation
Figure 1 D-l 4 Unsoldering Connections
10. Remove stator assembly from housing.
Il. Remove two screws and negative diode support. 13. Test rotor windings and slip rings for a ground,
using a test light or an ohmmeter. Test light should
not light; ohmmeter should read near infinite resist-
ance end of scale. See Figure
lD-17.
14. Test rotor windings for a short by connecting an
ohmmeter between the two slip rings. Ohmmeter
should read between 4.0 and 4.4 ohms. See Figure
lD- 18.
15.
Test stator windings for a ground, using a test
light or an ohmmeter. Test light should not light;
ohmmeter should read near infinite resistance end of
scale. See Figure
lD-19.

CHARGING SYSTEMlD- 33
Figure lD-17 Checking Rotor for Ground
Eigure lD-18 Checking Rotor for ShortFibwe 1 D-l 9 Checking Stator for Ground16. Check stator windings for a short, using a low
reading ohmmeter. Check two phases at a time by
holding ohmmeter prods alternately on winding
ends. Ohmmeter should read between
.26 and .29ohms. See Figure lD-20.
301 D20Figure 1 D-20 Checking Stator for Short
17. Clean slip rings with fine emery cloth and polish
them. To avoid generating flat surfaces on slip rings,
spin rotor on a lathe when cleaning and polishing.
Slip rings that are not concentric can be turned down
to a diameter of
l-1/4 inches. When doing this,
remove only enough material to just clean up the
worn surface, then polish slip rings and blow clean
with compressed air.
18. If alternator current output is low one or more
of the nine diodes may be defective. See Figure lD-3.
19. If a defective diode is suspected, test diodes.
Before testing diodes, disconnect them, otherwise it
is not possible to determine which diode is defective.
Use a test light supplied with a DC voltage of not
more than 24 volts.
20. To test a diode, place one test light prod on diode
connection and other on diode housing, then reverse
test light prods. Test light should light brightly in
,
CONNECTIONCONNECTION
I(ANODE)
(CATHODE)
IURRENTCURRENT ,I
CURREN’
FLOW+
+ HOUSING(CATHODE)HOUSING
(AN&E) 3lMD2Figure 1 D-2 1 Positive and Negative Diodes

1 D- 34 1973 OPEL SERVICE MANUAL!
I
one direction, but should not light at all in the otlier
direction. Diodes in each set of three should p&s
current and block current in the ‘same directions
Asthe others in the set. See Figure lD-21.
Removing Diodes/
Positive Diodes1. Press defective diode out of diode support, back-
ing-up support with a sleeve sliglitly larger than the
diode and pushing diode through with a shaft
slightly smaller than diode. See Figure lD-22.;
Figure 1 D-22 Removing Diode
Negative Diodes1. Clip lead from defective diode. Clip lead close
enough to diode so that tool will .function properly.
Figure 1 D-d3 Removing Diode2. Using Tool J-23526, press diode from support. See
Figure lD-23.
Installing Diodes
Positive Diodes1. Press new diode into diode support. See FigurelD-24.
Figure lD-24 Installing Diode
Negative Diodes1. Using Tool J-23526, press diode into support. See
Figure lD-25. Insert negative diode pigtail lead
through tool pilot.
Alternator Reassembly1. Clean and inspect all parts. Check brushes. Re-
place them if they have worn down to
3/8 inch.
2. Lubricate both bearings with special ball bearing
lubricant.
3. Press rear bearing on rotor shaft and install front
bearing into drive end frame.
4. Assemble stator together with windings into rear
end frame.
5. Install both diode supports.
6. Solder diode connections and ends of stator wind-
ings together. Since diodes are very sensitive to heat,
solder quickly using a very hot soldering iron.

WINDSHIELD WIPERSlE-41
Figurk 1 E-l 3 Cut Off Positive Brush Leads
i
Figure iE-14 Remove Negative Brush Retaining
S.X?WI
Cleaning apd Inspection of PartsWith the ekception of electrical parts and bushings,
clean all components in a cleaning solvent.
1. Check irmatare windings for ground, or open
circuit. If
b ground or open circuit is evident, the
armature must be replaced. If the armature checks
out, the c 2. Check brush springs. Spring pressure of new
brushes should be 6.35 to 8.47 ounces. Spring pres-
sure of worn brushes should be at least 3.5 ounces.
In case of /ower spring pressure, replace springs.
3. Check blushes for wear and replace if necessary.
Minimum brush length should be
.24’inch.4. Check d$ven gear for wear and replace if neces-
sary.
Assembly l/8inch layer’ of grease meeting GM Specification
02383. I
2. Install
d&en gear into housing3. Apply a small amount of grease to ball cavity of
driven gear and insert ball. See Figure lE-15.
Figure lE-15 Insert Ball into Driven Gear
4. Install transmission housing cover. See Figure
lE-
16.2. DRIVEN GEAR
3. CONTACT SPRINGS
4. TRANSMISSION
HOUSING COVER
Figure 1 E-l 6 Install Transmission Housing
Cover5. Solder positive brush lead(s) to brush holder(s).
Hold brush lead with needle nose pliers to prevent
solder from running up wire strands. See Figure
lE-
17.6. Install negative brush
7. Apply a small amount of grease to end of armature
shaft. Lightly oil armature shaft.
8. Insert brush springs and brushes into brush hold-
ers. Slide armature into housing, taking care not to
damage brushes.