1973 OPEL GT-R Service Manual

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

FRONT SUSPENSION3A- 34RM“PPtR BALL
SHOCK ABSORBER UPPER CONTROL,
UPPER CONTROL
ARM SHAFT
“:,‘,:“,‘,“,“, ,“pd,,‘, T/RUBBER BUMPER
\CROSSMEMBER
ROTOR
/LOWER BALL JOINTFRONT SPRING
Figure 3A-2 GT Front Suspension (Disc Brakes)
the upper and lower control arm are not in parallel
(anti- dive).The lower control arm is connected to the steering
knuckle with a ball joint.3A-4
Figure 3A-3 Cross Member Marking
Figure 3A-4 Front Suspension
- Opel 1900 Manta

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

3A- 6 1973 OPEL SERVICE MANUAL
Figure 3A-10 Steering Mast Clamp Bolt
assembly at the cross member to body support from
frame and let it down onto jack. See Figure
3A-11.
Figure 3A-1 1
Installation
GT
CAUTION: Fasteners are important attachingparts in
that they could affect the performance of vitaI com-
ponents and systems, and/or
coo/d result in major
repair expense. They must be replaced with one of the same part number or with an equivalent part if
replacement becomes necessary. Do not use a re-
placement part or lesser quality or substitute design. Torque
values
must be used as speciiied during reas-
sembly to assure proper retention of these parts.
I. Support front suspension and cross member on
jack and raise into position.
2. Attach cross member to front frame rail. Torque
to 36
lb.ft.
3. Install engine mounting nut? Remove engine sup-
port.
4. Install shock absorber mounting bolts and install
air cleaner.
5. Connect brakes hoses and bleed brakes as outlined
in Group 5.
6. Install radiator mounting bolt in support cross
member.
7. Push steering column downwards until a
l/8”
clearance is obtained between steering wheel hub and
switch cover.
8. With steering wheel in centered position and front
wheels straight ahead, tighten the clamp bolt at the
lower universal joint to 22
fbs.fi. and the clamp at
the upper universal joint to 14
lbs.ft. See Figure
3A-6.
9. Inr;tall mast guide sleeve stop bolt. Always install
new lock plate. See Figure
3A-7.
10. Remove front support stands and lower vehicle.
Installation Opel 1900 - Manta
1. With jack, lift up front suspension assembly so
that the individual attaching points coincide. At the
same time, insert lower steering mast into pinion
flange. See Figure
3A-12.
2. In the rear bolt cross member to body support.
Torque to 58
ft.lbs. When doing this with a suitable
tool, counterhold damper bushing which is installed
in a certain position, to prevent it from turning. For
this purpose, detach heat
deflectqr plate on right
vehicle side.
3. Torque front suspension assembly to frame attach-
ment to 47
ft.lbs.
4. Torque lower steering mast to pinion flange at-
tachment clamp bolt to 22
ft.lbs.
5. Reinstall both brake calipers. Torque to 72 ft.lbs.
Install brake line retainer.
6. On both sides install upper control arm ball joint.
Torque bolts to 29
ft.lbs.

FRONT SUSPENSION3A- 7
Figure 3A-12 Front Suspension Attaching Points
Always use new self-locking nuts.
7. Reinstall guard plate.
8. Crosswise torque wheel nuts to 65 ft.lbs.UPPER BALL JOINT REMOVAL AND
INSTALLATION
RemovalI. Place jack under spring eye and raise car. Remove
wheel from car.
2. Remove cotter pin and castle nut from upper ball
joint stud. Discard cotter pin.
3. Press ball stud from steering knuckle using puller
J-21687, and remove two (2) bolts attaching ball
joint to upper control arm. See Figure 3A-13.
4. If dust cap on upper ball joint is torn or missing,
the ball joint should be replaced.
Installation
CAUTION:
Fasteners are important attachingparts in
that they could
afEct the pertkmance of vital com-
ponents and systems, and/or could result in major
repair expense. They must be replaced with one of
the same part number or with an
equivaknt pa-t if
replacement becomes necessary. Do not use a re-
placement part of lesser quality or substitute design.
Torque values must be used as specified
durikg reas-
sembly to assure proper retention of these parts.Figure 3A-13 Upper Ball Joint
1. Install upper control arm ball joint with the off
center holes in flange showing towards the steering
knuckle spindle.
2. Install two (2) bolts attaching ball joint to upper
control arm. Torque nuts to 29 Ibft.
3. Install upper ball joint stud in%eering knuckle
and torque castle nut to 29
Ib.ft. on GT and 40 lb&.
on Opel
1900 - Manta.
4. Install new cotter pin, and replace wheel.
5. Always check caster and camber after installing
new ball joints.
LOWER BALL JOINT REMOVAL AND
INSTALLATIONNew lower ball joints have an axial play of up to
,020inch. The maximum permissible axial play of older
ball joints is
,080 inch. At an axial play of more than
,080 inch, the lower ball joint must be replaced. If the
dust cap is torn, loose, or missing, the lower ball joint
must also be replaced. See Figure
3A-14.The lower ball joints are checked for wear by using
Checking Gauge J-23402 for the GT, and using
Checking Gauge J-23745 for the Opel 1900
- Manta.
See Figure
3A-15.
Removal GT1. Raise car and support at rear of front frame rails.
2. Remove front wheel.

3A. 8 1973 OPEL SERVICE MANUAL
HOUSING
Figure
3A-14 Lower Ball Joint
1
CHECKING
I
Figure 3A-15 Ball Joint Checking Gauge Installed
3. Remove cotter pin from castle nut on ball joint
stud and back off castle nut two (2) turns. Hit ball
stud a sharp blow to break it loose. DO NOT REMOVE NUT.
4. Install spring compressor (J-21689) and compress spring until a distance of
3-l/8” is achieved between
spring compressor and lower spring leaf. See Figure
3A-16.
5. Disconnect shock absorber to lower control arm
\3cz
Figure 3A-16 Spring Compressa
attachment bolt and swing shock absorber out of the
Way.
6. Remove castle nut from ball joint stud. Prior to the
removal of the lower ball joint from the control
arm,
note the position of the locating notch, shown in
Figure
3A-17, in the rim of the ball joint housing.
Scribe or mark the control arm to facilitate align-
ment of the replacement ball joint during installa-
tion.
DIRECTION OFELONGATED
- 2” OF THE LOWER‘ELONGATED SLOT
CONTROL ARM CENTER LINE.w-17
Figure 3A-17 Lower Ball Joint Notch - GT
7. Pry off dust cap retainer and remove dust cap
being careful not to damage it.

FRONT SUSPENSION3A- 9
8. Press ball stud out of lower control arm.Removal Opel 1900 - MantaBefore raising vehicle, install Hooks J-23697 on re-
spective vehicle side to cross member and upper con-
trol arm. See Figure 3A-7.
1. Raise car and support at rear of front frame rails.
2. Remove front wheel.
3. At the lower control arm ball joint, remove castle
nut cotter pin and slacken back nut so that the thread
can no longer be damaged.
4. With a suitable drift, detach ball joint from steer-
ing knuckle. With jack, lift up lower control arm,
unscrew castle nut and remove Hooks J-23697.
5. Unscrew upper control arm ball joint and suspend
front wheel hub and brake caliper in wheel house. Do
not turn upper control arm ball joint flange, as this
would result in a change of camber.
6. Remove defective lower control arm ball joint
using Tools J-9519 and Receiver J-23754.
Installation GT
CAUTION:
Fasteners are important attachingparts in
that they could affect the performance of
vitaI com-
ponents and systems, and/or could result in
ma&r
repair expense. They must be replaced with one of
the same part
numer or with an equivalent part if
replacement becomes necessary. Do not use a
re-
placement part of lesser quality or substitute design.
Torque values must be used as specified during reas-
sembly to assure proper retention of these parts.1. When pressing the ball joint in place, make certain
the locating notch in the lower rim of the ball joint
matches the alignment reference mark placed on the
lower control arm prior to removal. The notch in the
ball joint bottom plate, identifying the direction of
the elongated slot, must point towards the brake
drum backing plate. See Figure
3A-17. Alignment
must be within 2 degrees of lower control arm center-
line. If proper positioning of the ball joint is not
accomplished, the result is a limitation of the neces-
sary ball stud movement. If ball stud movement is
limited, an interference between the ball stud and
housing is created, and binding or even fracture may
occur. Replacement ball joints may or may not have
marking notch as shown in Figure
3A-20. If it does
not have a marking notch, the joint is completelysymetrical and may be installed in any position.
When pressing in ball joint do not press on bottom
plate, but on ball joint housing only.2. Install dust cap on lower ball joint and fill with
chassis lubricant. Attach dust cap retainer.
3. Press ball joint into steering knuckle. Use
J-9519-3 as installer and J-21690 as a supporting
sleeve.4. Install castle nut on ball joint stud and torque to
40
Ib.ft. Install new cotter pin.
5. Reconnect shock absorber to lower control arm
and torque to 30 lb.ft.
6. Remove spring compressor.
7. Install front wheel, and lower the car.
8. Always check caster and camber after ball joint
replacement.
Installation Opel 1900 - Manta
CAUTION:
Fasteners are important attachingparts in
that they could
aff’ect the performance of vital com-
ponents and systems, and/or could result in
ma&r
repair expense. They must be
rep/aced with one of
the same part number or with equivalent parts, if
rep/acement becomes necessary. Do not use a re-
p/acement part of lesser quality or substitute design.
Torque valves must be used as
specitied during reas-
sembIy to assure proper retention of these parts.1. Drive new ball joint into lower control arm using
Tools J-9519 as installer and J-23755 as a supporting
sleeve. Do not strike onto ball joint bottom.
The ball joint is maintenance-free. It is supplied as an
assembly only and cannot be disassembled further.
2. On new lower control arm ball joint, make sure
that the marking groove in the housing bottom in
alignment with the axis of the lower control arm.
Permissible deviation: minus 2 degrees to plus 2 de-
grees.This is required, to obtain the maximum freedom of
movement of the ball stud in the housing. See Figure
3A-18.3. Attach steering knuckle together with front wheel
hub and brake caliper to lower control arm ball joint.
Torque castle nut to 54
ft.lbs.4. Attach ball joint to upper control arm and torque
to 29
ft.lbs. Always use new self-locking nuts.
5. Install wheel and tighten nuts to a torque of 65
ft.lbs.6. Lower car and check caster and camber.