transmission OPEL GT-R 1973 Owner's Manual

3G- 581873 OPEL SERVICE MANUALTire Wear IrregularitiesAn additional cause of vibrations may sometimes be
tire wear irregularities. These can also produce noise
disturbances, and can be generally corrected by
rotating the tires, Figure
3G-6. Before proceeding
further, locate and correct the cause of the irregular
tire wear. See Figure
3G-7.Use the criss-cross method of rotation of tires only
when all four tires are equally worn. In some in-
stances, it may be necessary to put the truest running
assemblies (those with the lowest tolerances) on the
front of the car.
Wheel Nut Torque end Tightening SpecificationsDuring all wheel installations, it is important to use
the correct procedures for installing wheel nuts and
torquing them uniformly and in proper sequence.
This is important in order to avoid possible distor-
tion of the brake drum or disc, and to minimize
damage to lug and nut threads and wheel stud holes.
To assure uniform tightening of wheel lug nuts, the
following procedure is recommended:
1. Install wheel lug nuts in a criss-cross pattern and
tighten just enough to seat wheel against hub. This
assures proper piloting of the wheel on its hub.
2. Tighten lug nuts uniformly to proper torque of 65
Ib.ft. using criss-cross pattern.
An impact wrench should not be used, as uniform
torque control cannot be maintained.
Summary of Diagnosis end Correction of Tire and
Wheel Vibration1. Inflate all tires to recommended pressure and
road-test car with owner to define problem.
2. Spin front tire/wheel assemblies with wheel driv-
ing equipment. Rear wheels may be spun with tires
off the ground and with one wheel held at a time. The
offending tire may cause vibration that may be felt
by touching the bumper or fender. By process of
elimination, determine offending tire/wheel assem-
bly.
3. Check for tire/wheel unbalance. Balance, if neces-
sary.4. Check each tire/wheel assembly on the car for
radial runout on the tire tread. Wheel and tire assem-
blies exceeding
.050 inches may be considered as
offending assemblies. Offending tire/wheel assemblyshould be deflated and the tire repositioned (indexed)
180 degrees from original location.
5. After repositioning, rebalance tire/wheel assembly
(static and dynamic preferred).
6. Test drive and evaluate correction.
The following procedure should be used to determine
cause of roughness or vibration with car in operation
at various speeds:
I. Jack up all wheels having jack support rear end of
car at center of rear axle housing.
2. With transmission in “Drive”, run engine at vari-
ous car speeds to note speeds at which vibration or
roughness occurs.
3. Remove rear wheels and run engine again at the
critical speeds noted in step 2. If roughness is gone,
the condition is caused by unbalanced wheel and tire
assemblies.
4. If roughness still exists with rear wheels removed,
remove rear brake drums and repeat the running
test. Elimination of the roughness indicates out of
balance brake drums.
5. If roughness still exists with brake drums
removed, run engine with transmission in “Neutral”.
Elimination of the roughness indicates that propeller
shaft is out of balance. Continued roughness indi-
cates an out-of- balance engine.
ABNORMAL TIRE WEAR
General Operating ConditionsAssuming that there is no misalignment condition to
cause abnormal wear, the life of tires depends largely
upon car operation conditions and driving habits.
Tires wear at a much faster rate in some localities
than in others because of road and operating condi-
tions. Some types of roads are much more abrasive
than others. Tire wear is also dependent upon the
number of hills and mountains which the car must
go up and down, the severity of grades, the number
of starts and stops, driging speeds, the amount of rain
and snow, and prevailing temperatures. Tire
wear
increases rapidly with speed, temperature, and loadon tire. Tires used at low speeds, in cool climates, or
with light loads will have longer life than tires used
for high-speed driving in hot climates with heavy
loads.
Driving habits have a very important hearing on tire
life. A careful driver may obtain much greater mile-
age from a set of tires than would be obtained by a

4A- 21973 OPEL SERVICE MANUAL
PROPELLER SHAFT AND CENTRAL JOINT
CONTENTS
Subject
DESCRIPTION AND OPERATION:
PropellerShaftandCentralJoint. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .DIAGNOSIS: (Not Applicable)
MAINTENANCE AND ADJUSTMENTS: (Not
Applicable)
MAJOR REPAIR:
’Propeller Shaft Removal andInstallation
. . . . . . . ..-....Disassembly andAssembly of CentralJoint
. . . . . . . . . . . .SPECIFICATIONS:
Propeller Shaft and Central Joint Specifications . .
DESCRIPTION AND OPEqATlON
PROPELLER SHAFT AND CENTRAL JOINTDue to the use of both automatic and manual trans-
missions, propeller shafts of various lengths are re-
quired depending upon vehicle, engine, and
transmission (manual or automatic) application. The
propeller shaft is of a strong design due to increased
engine torque. It is also a one piece tubular shaft, but
it has two universal joints. See Figure 4A-1. The
front universal joint attaches to the transmission out-
put shaft by a splined slip joint. The rear universal
joint attaches to the pinion extension shaft flange by
Page No.
4A-2
4A-3
4A-3
4A-6two U-bolts. The splines of both propeller shafts are
lubricated internally with transmission lubricant. An
oil seal in the rear of the transmission extension pre-
vents loss of lubricant and entrance of harmful for-
eign material.
The torque tube which houses the drive pinion exten-
sion shaft is bolted to the differential housing. The
torque tube is pivoted in rubber elements of the cen-
tral joint support bracket which is bolted to the floor
panel. The support bracket and rubber parts of the
torque tube
arc termed the central joint. The front
end of the drive pinion extension shaft rides in a ball
bearing mounted in rubber in the central joint.
CENTRAL JOINT\REAR U-JOINT
FRONT U-JOINT
4A-1Figure 4R1 Propeller Shaft

PROPELLER SHAFT AND CENTRAL JOINT4A- 3MAJOR REPAIR
PROPELLER SHAFT REMOVAL AND
INSTALLATION
Removal
1. Raise rear of car and support on jack stands at rear
jack brackets.
2. Disconnect parking brake cable equalizer from
rod.3. On the Opel
1900 and Manta, unhook parking
brake cable from floor panel.
4. On the Opel 1900 and Manta, unhook exhaust
system and let it down.
5. Mark the mating parts of the U-joint and the drive
pinion extension shaft flange.
6. Loosen bolt locks and remove bolts or nuts.
7. Work propeller shaft slightly forward, lower rear
end of shaft and slide assembly rearward. Remove
thrust spring from front of propeller shaft.
S. Install plug in transmission extension housing to
prevent loss of lubricant.
installation
CAUTION:
Fasteners in the foJlowing steps are impor-
tant attaching parts in that they could affect the
performance of
vital components and systems, and-
/or could
result in major repair expense. They must
be replaced with one of the
samepart number or with
an equivalent part
ifreplacement becomes oecessary.
Do not use a replacement part of lesser quality or
substitute design. Torque values must be used as
specirid during reassembly to assure proper reten-
tion of these parts.1. Remove plug from rear of transmission.
2. Slide thrust spring onto transmission output shaft
and slide propeller shaft through the oil seal and onto
the transmission output shaft. Make certain trans-
mission rear seal is not damaged.
3. Align rear universal joint and pinion flange locat-
ing marks and secure with respective bolts and lock
plates. Torque bolts to 11
lb.ft. Bend lock plate tangs
to secure bolts or nuts.
4. Connect parking brake cable equalizer to brake
rod and adjust to specifications.
5. On the Opel 1900 and Manta connect parking
brake cable to floor panel.DISASSEMBLY AND ASSEMBLY OF THE
CENTRAL JOINT
Disassembly of Central Joint1. Raise and support rear of car under axle tubes.
2. Release brake line bracket from rear of torque
tube.3. Disconnect parking brake cable equalizer and re-
turn spring from brake rod.
4. On the Opel 1900 and Manta, unhook exhaust
system and let it down.
5. Mark universal joint and flange. Disconnect pro-
peller shaft from flange and support it out of the way.
6. Support torque tube with floor jack using mini-
mum pressure.
7. Remove the central joint bracket to underbody
attaching bolts.
8. Allow floor jack to lower the torque tube.
9. Disconnect torque tube from differential carrier by
removing the attaching bolts.
10. Install pinion flange holder J-8614 and remove
self-locking flange nut. See Figure 4A-2.
FLANGE HOLDER4A-2
Figure 4A-2 Removing Pinion Flange Nut
11. Pull pinion flange using J-8614 adapter. See Fig-
ure 4A-3.
12. Remove drive pinion extension shaft from torque
tube using a soft faced mallet. See Figure 4A- 4.
13. Removal ball bearing from cushion.
14. With torque tube placed in vise remove support

4S- 91973 OPEL SERVICE MANUAL
DIAGNOSIS
DIFFERENTIAL TROUBLE DIAGNOSISConditionPossible Cause
1. Noise is the same in1. a) Road noise.
“Drive” or “Coast”.b) Tire noise.
c) Front wheel bearing noise.
d) Front or rear U-joint angle
too great.
2. Noise changes on a2. a) Road noise.
different type of road.b) Tire noise.
3. Noise lowers tone as3. Tire noise.
car speed is lowered.
4. Similar noise is pro-4. a) Engine noise.duced with car standingb) Transmission noise.
and driving.c) Driveline angle.
5. Vibration5. a) Rough rear wheel bearing.
b) Tire unbalance.
c) Worn universal joint in
propeller shaft.
d) Front or rear U-joint angle
too great.
e) Mis-indexed, propeller shaft
at companion flange.
tJ Companion flange runout too
6. A knock or click6. A brinelled rear wheel bearing
approximately every two (2)
revolutions of rear wheel.
7. Noise most pronounced on7. Differential side gear and pin
turns.
8. A continuous low pitch8. Pinion bearing.
whirring or scraping noise
starting at relatively low
speed.9. Drive noise, coast9. Ring and pinion gear.
noise or float noise.
10. Clunk on accelera-
10. a) Worn differential cross sha
tion or deceleration.in case.
11. Groan in “Forward” or11. Wrong lube in differential.
“Reverse”.
12. Clunk or knock on12. a) Excessive end play of axle
rough road operation.to differential cross shaft
b) Excessive differential gear
clearance.

REAR AXLE48. 9
MAJOR REPAIRREMOVAL AND INSTALLATION OF REAR AXLE
ASSEMBLYRemoval
1. Raise rear of car with floor jack under differential
carrier and position jack stand under jack bracket on
each side of car. Remove rear wheel assemblies and
one brake drum.
2. Disconnect parking brake cable equalizer and re-
turn spring from brake rod.
3. Detach parking brake cable from actuator lever
and backing plate at wheel with brake drum
removed. Disconnect cable from lower control arm
brackets and pull loose end over exhaust system.
4. Disconnect shock absorbers at lower end.
5. Disconnect track rod at left end.
6. On cars equipped with a stabilizer rod, disconnect
the shackles at rear axle housing.7. Disconnect universal joint from pinion flange and
support or tie propeller shaft out of way after mark-
ing mating areas. If propeller shaft is removed, install
plug in rear of transmission to prevent loss of lubri-cant.8. Disconnect brake hose from brake pipe at differen-
tial and remove retaining clip.
9. Lower rear axle assembly far enough to remove
coil springs.
10. Remove central joint support bracket to under-
body retaining bolts.
11. Disconnect lower control arms at rear axle assem-
bly bracket and roll the assembly from under the car.
See Figure
4B-2.Installation
CAUTION: Fasteners in the following steps are impor-tant attaching parts in that they could affect the
performance of vital components and systems, and-
/or coo/d
resuJt in major repair expense. They must
be rep/aced with one of the same part number or withREAR SHOCK ABSORBERS
SPRING SEAT
4B-1Figure
4B-l Differential and Rear Suspension Assembly

6A- 8 1973 OPEL SERVICE MANUAL
Actual adjustment is made by backing off adjusting
nut at the rocker arm until clearance exists between the valve stem, rocker arm, and lifter. Then slowly
tighten adjusting nut until clearance is eliminated.
When clearance is eliminated, turn adjusting nut one
full turn (clockwise). This positions the hydraulic
piston of the hydraulic lifter mid-point in its total
available travel, and no further adjustment is re-
quired.
MAJOR REPAIR
ENGINE ASSEMBLY REMOVAL AND
INSTALLATION
Removal (Opel 1900 and Manta)’
The engine assembly on the Opel 1900 and Manta
can be removed together with the transmission
through the top of the engine compartment.
1. Remove hood (scribe hood hinge to hood mount-
ing location).
2. Disconnect battery negative cable.
3. Drain coolant at lower radiator hose.
4. Remove upper and lower radiator hoses.
5. Remove radiator and fan
shrbud.
6. Disconnect heater hoses.
7. Disconnect brake booster
vacuum hose.
8. Remove air cleaner.
9. Disconnect electrical connections and accelerator
linkage. 10. Remove console.
11. Remove shift lever boot, plate, and shift lever.
12. Raise car on hoist.
13. Disconnect fuel line at pump.
14. Remove front stone shield.
15. Disconnect speedo-cable, back-up light switch,
and clutch cable.
16. Remove drive shaft. I
17. Disconnect exhaust pipe
ar$l bell housing sup-
port.
18. Disconnect transmission support. See Figure
6A-7. 19. Remove engine mount bolts. See Figure
6A-8.
20. Attach hoist chains.
21. Lift engine and transmission assembly out of car.
Figure 6A-7 Transmission Support Bolts . Opel 1900
and Manta Series
Figure
6A-B Engine Mount Bolts - Opel 1900 and
Manta Series
Removal (GT)
The removal and installation of the 1.9 liter engine is only possible towards the floor and from below
Fig, 6A-9 Left Front Engine Suspension with Cross
Member (GT)

ENGINE MECHANICAL AND MOUNTS6A- 9
The engine does not rest on the front suspension
cross member as in the Opel 1900 and Manta but on
a separate cross member. On removal and installa-
tion of the engine the front suspension cross member
need not be detached.
Fig. 6A-10 Right Front Engine Suspension with Cross
Member
(GT)1. Disconnect battery negative cable,
2. Remove air cleaner.
3. Drain radiator coolant by disconnecting lower
radiator hose. Disconnect upper radiator hose. See
Figure 6A-11. Radiator need not be disconnected.
4. Disconnect all electrical connections:
a. Coil wire to distributor.
b. Wires from alternator. Remove unit and bracket.
c. Battery positive cable at starter switch.
d. Oil pressure switch wires at cylinder block.
e. Wires from starter solenoid.
5. Remove vacuum hoses at tee mounted to intake
manifold. Remove tee from manifold to avoid inter-
ference during engine lowering.
6. Remove throttle linkage and carburetor.
7. Disconnect heater hoses.
8. Disconnect water valve bracket to manifold,
9. Remove gear shift lever.
10. Using suitable equipment lift up engine so that
front engine mounts are somewhat relieved.Figure 6A.1
1 Radiator Hose Clamp Location
11. Raise vehicle, both front and rear end. A two post
axle type hoist
IS recommended for this operation.
12. Disconnect fuel line at fuel pump and plug. Be
sure fuel line is disconnected from any engine and
transmission clips.
13. Disconnect speedometer cable from transmis-
sion.14. Disconnect clutch cable.
15. Disconnect drive shaft at rear universal joint and
remove.
16. Disconnect exhaust at manifold.
17. Remove tailpipe and mufIler hangers.
18. Remove ground strap from engine to side rail.
19. Detach transmission cross member from trans-
mission and frame. See Figure 6A-12.
20. Detach engine cross member from engine and
frame.21. Carefully lower engine and transmission and
remove from underneath vehicle.

6A- 101973 OPEL SERVICE MANUAL
Fig. 6A.12 Transmission Cross MemberInstallation (Opel 1900 and Manta)1. Lower engine and transmissior assembly into car.
2. Install components as
remov&d in steps .1 through
19 above.
Installation (GT)1. Install bell housing, transmission and starter.
2. Using suitable equipment raise assembly into vehi-
cle.
3. Install components as removed in steps 1 thru 21.
ENGINE OIL PAN REMOVAL AND INSTALLATION
Removal (Opel 1900 and Manta)To remove the engine oil pan, a device similar to the
one illustrated in Figure 6A-14 can be made and used
to support the front of the engine. This particular
device was made up using hardwood, bolts, and
chain.
1. Assemble chains to engine.
Figure 6A-14 Engine Support Tool
- Opel 1900 and Manta.

6A- 18 1973 OPEL SERVICE MANUAL
pressure. If heavy pressure is required, shell was not
started squarely and will be distorted if force into place.
12. Place lower bearing shell in bearing cap, then
check clearance
with plastic-type gauge, as previ-
ously described.
13. The desired clearance with a new bearing is
.0009” to .0025”. If this clearance cannot be obtained
with a standard size bearing, insert an undersize
bearing and check again
w&h plastic-type gauge
material.
14. When the proper size bearing has been selected,
clean out all plastic gauge material, oil the lower
shell and reinstall bearing cap. Clean the bolt holes
and lube bolts, then torque cap bolts to 72 lb. ft. The
crankshaft should turn freely at flywheel rim; how-
ever, a very slight drag is permissible if an undersize
bearing is used.
15. If the thrust bearing shell is disturbed or replaced
it is necessary to line up the thrust surfaces of the
bearing shell before the cap bolts are tightened. To
do this, move the crankshaft fore and aft the limit of
its travel several times (last movement fore) with the
thrust bearing cap bolts finger tight.
16. After bearing is installed and tested, loosen all
bearing cap bolts
l/2 turn and continue with other
bearings. When bearings have been installed and
tested, tighten all bearing cap bolts to 72 lb. ft.
17. Replace rear bearing oil seals.
18. Install pipe and screen assembly and oil pan.
Installation of Rear Bearing Oil
Seals (Engine in Vehicle)
1. Remove transmission, bell housing and clutch.
Refer to appropriate section for removal procedures.
Figure 6A-28 Removing Rear Main Oil Seal
2. Remove flywheel.
3. Punch a hole into oil seal and screw in a sheet
metal screw and pull out oil seal. See Figure
6A-28.
4. To insure proper sealing, lubricate seal with a
suitable protective grease and install on taper ring
J-22928. Turn seal to ensure lip of seal is not turned
back. See Figure
6A-27.
OIL SEAL’6A-29
Figure
6A-29 Installing Oil Seal on Tool J-22928
5. Place tapered ring with oil seal on crankshaft
flange and move lip of seal
over rear of crankshaft.
Be careful not to tilt seal.
Figure 6A-30 Installing Rear Main Bearing Oil Seal
6. Drive in oil seal using Tool J-22928-2. See Figure
6A-30.
7. Install flywheel, clutch, bell housing and transmis-
.

6A- 28 1973 OPEL SERVICE MANUAL
Part
ConnectingRod Bolts..........................................................
Crankshaft Main Bearing Bolts
..........................................
FlywheeltoCrankshaft AttachingBolts..........................
Cylinder Head Attaching Bolts....Cold 72 -Warm 58
Camshaft Sprocket Attaching Bolts................................
Generator Bracket to Cylinder Block
Attaching Bolts ..................................................................
Generator Bracket to Timing Case Attaching Bolts
....
Crankshaft Pulley Attaching Bolts ....................................
Rocker Arm Stud in Cylinder Head ..................................
Spark Plugs ........................................................................\
....
Clutch Housing to Cylinder Block Attaching Bolts
......
Timing Case to Cylinder Block AttachingBolts ............
Water Pump to Timing Case AttachingBolts................
Engine Support to Cylinder Block Attaching Bolts
......
Rear Engine Suspension to Transmission Rear Bearing Retainer Bolts ....................................................
Transmission to Clutch Housing Attaching Bolts
........
Starter to ClutchHousing AttachingBolts....................
Support to Starter Attaching Nut
....................................
Intake and Exhaust Manifold to Cylinder Head Attaching Bolts ..................................................................
Unless Otherwise Noted:
10
@i Bolt (15 MM Hall.....................................................................- -
36
72
43
18
;i
72
29
30
36
14
11
40
22
29
40
4
33 ............30
8 MM Bolt (13 MM Head)........................................................................\
........................................................................\
........................................15
6 MM Bolt (10 MM Head)
30 Lb.In.
Torque
Lb.Ft.
GENERAL SPECIFICATIONS
Type - No. of Cylinders
Valve Arrangement........................................................................\
........................................................................\
......................................................I;nlinzai
Bore and Stroke Piston Displacement Cu. In.
........
3.66 x1:;:;
Compression Ratio......................................................................................\
........................................................................\
........................................................................\
........................................
\fô\
²…..............7.6:1Octane Requirement........................................................................\
..........
Firing Order........................................................................\
........................
Regular - Lo;-?::
....................Cylinder Block Material....... ...............................................................................\
..............................................Cast Iron
Crankshaft Bearings Number and Type 5 Removable Steel Backed
In-Metal Babbitts
Bearing Which Takes End Thrust
........................................................................\
...................5
Connecting Rod Bearing Material
........................................................................\
..................
Steel Backed Tri-Metal Babbttts
Piston Material and Surface Aluminum Alloy, Lead Coated
Piston Pin Offset
........................................................................\
............,031 In. to the RightCompression Rings Material and Surface Treatment
No.
1....... ........... ............... ........ ............. ................Chrome-plated, Cast Iron
- Rectangular
No. 2
........................................................................\
..............................Cast Iron - Tapered
Oil Ring
........................................................................\
..................Chrome-plated, Cast Ir?n
Location of All Piston Rings
........................................................................\
Above Ptston Pm
Camshaft Material
........................................................................\
....................Alloy Cast Iron
Camshaft Drive........................................................................\
........................................Chajn
Number and Type of Camshaft Bearings 4 Steel-Backed Babbttt
Valve Lifter Type
..............................................................................................\
..........................................~..........Hydraulic
Oiling System Tvoe........................................................................\
Circulatmg High Pressure
Oil
&ppiied to: - .
Bearing Surfaces, Crankshaft, Camshaft and Connecting Rods............................Pressure
Piston, Pins
........................................................................\
............................................Vapor
Cvlinder Walls........................................................................\
..........................Nozzle Spray
Rocker Arms _,,,..,,....,._..___.,,..,,..............,,,,...,.......,..,,,.,.,,.....\
....,,...,.,.................~...... Pressure
Oil Reservoir Capacity
- Quarts .,,,...,,__.,,..,..,,..,...,..,,,...,,..............,,,... 3 l/4 With Dry Fdter
Oil Filter
- Type ,,....,__.,,...,....,....,,..,,,..,,...........,........................\
............ Throw Away Element