1973 OPEL GT-R air suspension

FRONT SUSPENSION3A- 15
SHOCK ABSORBER REMOVAL ANDINSTALLATION
Removal
Opel 1900. Manta1. Raise car and support with stands.
2. Remove upper attaching nuts from shock ab-
sorber.3. Remove lower attaching nut, lockwasher, and
bolt.
4. Compress shock absorber and remove from car.
Removal GT1. Remove air cleaner. See Figure 3A-24.
Figure 3A-24 Removal of Air Cleaner
2. Remove plastic cover over shock absorber upper
attachment.
3. Raise car and support with stands.
4. Remove upper attaching nuts from shock ab-
sorber.5. Remove lower attaching nut, lockwasher, and
bolt.
6. Compress shock absorber and remove from car.
Installation Opel 1900. Manta1. Inspect shock absorber for damage and seal leaks.Always replace the upper and lower rubber grom-
mets when replacing a shock absorber.
2. Install the lower grommet retainer and grommets
on shock absorber. Compress shock absorber and
place in position.
3. Install lower attaching bolt and nut. Torque to 30
lb.ft.4. Install nuts on upper attaching studs. Tighten nuts
until distance from top of nut to stud is approxi-
mately
l/2 inch. See Figure 3A-25.5. Install plastic cover.
Installation GT1. Inspect shock absorber for damage and seal leaks.
Always replace the upper and lower rubber grom-
mets when replacing a shock absorber.
2. Install the lower grommet retainer and grommets
on shock absorber. Compress shock absorber and
place in position.
3. Install lower attaching bolt and nut. Torque to 30
lb. ft.
4. Install nuts on upper attaching studs. Tighten nuts
until distance from top of nut to stud is approxi-
mately
l/2 inch. See Figure 3A-25.5. Install plastic cover.
6. Install air cleaner.
FRONT SPRING REMOVAL AND INSTALLATION
Removal (GT)1. Raise car and support at rear of front frame rails
with stands.
2. Remove front wheels.
3. Remove cotter pin from castle nut on lower ball
joint studs and back off castle nut two (2) turns. Hit
ball stud a sharp blow to break it loose. Do not
remove nut.4. Install J-21689 spring compressor and compress
the spring until 3-l/8” clearance is obtained between
spring and compressor.
5. Disconnect both shock absorbers at their lower
attachment. Compress both shock absorbers.
6. Support the rail of J-21689 Spring Compressor
with a jack. Remove lower control arm to cross
member attaching nuts and bolts.

FRONT SUSPENSION3A- 17Torque values must be used as specified during reas-
sembly to assure proper retention of these parts.1. Attach lower control arm to front spring eye.
Torque bolts to 18
lb.ft.2. Install spring compressor on spring and compress
spring to appropriate length.
3. Raise jack with spring compressor, spring and
control arm assembly into position under the car.
4. Install lower ball joints and torque nuts to 54
Ib.ft.Install new cotter pin.
5. Attach lower control arms to frame cross member
using new lock nuts.
6. Attach both shock absorbers. Torque bolts to 30
lb.ft.7. Remove spring compressor.
8. Install front wheels.
On replacement of the damper bushings on the front
springs, only the one-part damper bushing is in-
stalled for either the two-leaf or three-leaf spring.
For proper location of the marking lugs, see Figure3A-26.
Installation (Opel 1900. Manta)
CAUTION: Fasteners are important attachingparts in
that they
co&d affect the performance 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 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. Properly seat spring between lower control arm
and cross member.
2. Raise jack and place lower control into position.CROSS SECTION
SA-26Fig. 3A-26 Front Spring Damper Bushing.
3. Attach lower control ball joint to steering knuckle
and torque nut to 54
lb.ft.4. Tighten lower control arm to cross member bolt
to 43 lb.ft.
5. Attach stabilizer bar to cross member to body
support.
6. Install shock absorber and torque lower attaching
nut and bolt to 30
lb.ft.7. Install nuts on upper shock absorber attaching
studs. Tighten nuts until a distance from top of nut
to stud is approximately
l/2 inch.
8. Install front wheels and tighten nuts to 65
lb.ft.9. Remove stands and lower car.
SPECIFICATIONSBOLT TORQUE AND FRONT END ALIGNMENT

3C-22 1973 OPEL SERVICE MANUAL.
FRONT END ALIGNMENT
CONTENTS
SubjectPage No.
DESCRIPTION AND OPERATION:
FrontWheelAlignment
. . . . . . . . . . . . . . . . . . . . . . ..“...........................DIAGNOSIS: (Not Applicable)
MAINTENANCE AND ADJUSTMENTS:
Inspection Before Checking Front Wheel Alignment
AdjustingCaster
. . . . . . . . ...’ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Adjusting Camber
. . . . . . . . . . . . . . . . . . . . . . . . . . * . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Adjusting Toe-In
. . . . . . . . . . . . . . * . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .King Pin Inclination
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .MAJOR REPAIR: (Not Applicable)
SPECIFICATIONS:3C-223C-223C-233C-253C-253C-26
Wheel Alignment Specifications
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3C-26
DESCRIPTION AND OPERATIONFRONT WHEEL ALIGNMENT
Wheel alignment is the mechanics of adjusting the
position of the front wheels in order to attain the
least steering effort with a minimal amount of tire
wear.handling, but require only reasonable accuracy to
provide normal tire life. With the type of front sus-
pension used, the toe-in adjustment is much more
important than caster and camber are as far as tire
wear is concerned.
Correct alignment of the chassis is essential to proper
alignment of front and rear wheels. Briefly, the es-
sentials are that the frame must be square in plain
view within specified limits, that the top and bottom
surfaces of the front cross member must be parallel
fore and aft, and that the upper and lower control
arm must be at correct location in respect to shafts
and the front cross member. All bushings, ball joints
and bolts must be of proper torque and in usable
condition.Caster and camber adjustments need not be consid-
ered unless visual inspection shows these settings to
be out, or unless the car gives poor handling on the
road. In the majority of cases, services consisting of
inflating tires to specified pressure and interchanging
tires at recommended intervals, balancing all wheels
and tires, adjusting steering gear and setting toe-in
correctly will provide more improvement in car han-
dling and tire wear than will other front end align-
ment adjustments.
Wheel and tire balance has an important effect on
steering and tire wear. If wheels and tires are out of
balance, “shimmy” or “tramp” may develop or tires
may wear unevenly and give the erroneous impres-
sion that the wheels are not in proper alignment. For
this reason, the wheel and tire assemblies should be
known to be in proper balance before assuming that
wheels are out of alignment.The correct use of accurate front end alignment
equipment is essential to determine whether front
suspension parts have been damaged by shock or
accident, and to obtain correct alignment settings
after new parts have been installed.
MAINTENANCE AND ADJUSTMENTS
Inspection Before Checking Front Wheel AlignmentClose limits on caster, front wheel camber, andBefore making any adjustment affecting caster, cam-
theoretical king pin inclination are beneficial to carber, toe-in, theoretical king pin inclination, or
steer-

FRONT END ALIGNMENT 3C-23
ing geometry, the following checks and inspections
must be made to insure correctness of alignment
equipment readings and alignment adjustments.
1. The front tires should have approximately the
same wear and all tires must be inflated to specified
pressures (see Wheel and Tire Specifications
- Sec-
tion 3G).
2. Check front wheel bearings for looseness and ad-
just if necessary (see Front Suspension Adjustments
- Section 3A).
3. Check for run-out of wheels and tires, (see Section
3G).
4. Check wheels and tires for balance and correct if
out-of-balance (See Section 3G).
5. Check for looseness at ball joints and tie
rdd ends;
if found excessive, it must be
corxcted before align-
ment readings will have any value.
Figure SC-Z Spring Compressor J-2 1689 Installed
6. Check shock absorber action and correct if neces-
sary. Consideration must be given the optional
equipment on the car, undercoating, dirt, etc.
7. It is advisable to check the condition and accuracy
of any equipment being used to check front end
alignment and to make certain that instructions of
the manufacturer are thoroughly understood.
ADJUSTING CASTER (GT)
4. Remove upper control arm shaft,
5. Remove upper control arm from shock absorber
support, being careful not to lose toothed washers.
6. Adjust caster by installing selective toothed wash-
ers on both sides of control arm shaft, between con-
trol arm and shock absorber support. Never use
CAUTION: Front suspension fasteners are impor- more than one washer at any one location. The total
tant attaching parts in that they could
affectthickness, front and rear washer, must equal .48”.
the performance of uital components and sys-
tems, and/or could result in major repair expense.
There are only two possible caster changes that can
be made.
They must be replaced with one of the same
part
number or with an equiualentpart ifreplacement
becomes necessary. Do not use a replacement part
Of lesser quality or substitute design. Torque
values must be used as specified during reassem-
bly to mure proper retention of these parts.
7. Using a drift to align holes, replace control arm
shaft in the direction as shown in Figure
3C-3.
Torque hex nut to 33 lb.ft. Make certain that crown
of both plate washers shows outward.
To change caster, three washers are available
- one
with a
.12” thickness, one that is .36” thick, and one
.24” thick. Toincrease caster place one of the thin
washers at the front of the control arm shaft and one
of the thick washers at the rear.
To decrease caster
place one thick washer at the front of the control
arm shaft and one thin washer at the rear.
1. Position jack below front suspension cross mem-
ber and raise front end of car. 8. Remove spring compressor, and install front
wheel and torque wheel nuts to 72 ft. Ibs.
9. Recheck caster.ADJUSTING CASTER (OPEL
1900. MANTA)
2. Place jack stands below front frame side members
and remove front wheel on side which caster is to be
adjusted. 1. Jack up vehicle and remove front wheel on the side
on which caster is to be adjusted.
3. Install front spring compressor J-21689 and com-
press spring. See Figure
3C-2.
2. Support vehicle below both lower control arms.
See Figure
3C-4.
3. Unscrew hex nut from upper control arm shaft
and pull out shaft.
4. Adjust caster by replacing washers (A) (front) and

3D- 301973 OPEL SERVICE MANUALFigure 3D-8 - Removing Clamp Bolt3. Remove cotter pin located on left and right tie rod
end and unscrew nut.
4. Using Tool J-21687, press tie rod ends out of
steering arms.
5. Disconnect steering gear housing from front sus-
pension cross member and remove steering gear
together with tie rods.
Installation . GTCAUTION: Fasteners are important attaching parts in
that they could affect the performance 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 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. Position steering gear on front suspension cross
member and torque attaching bolts to 18
lb.ft.2. Position tie rod ball studs in steering arms; install
nuts and torque to 29 lb.ft. Lock in position with new
cotter pins.
3. Fully turn steering wheel so that flat or cutout
surface on lower portion of steering shaft is parallel
to flexible coupling bolt hole.
4. Install the lower end of steering shaft to the flexi-
ble coupling and adjust dimension between steering
wheel hub and direction signal switch housing cover
to
l/8 and 3/32 inch. Maintain adjustment by tight-
ening flexible coupling bolt and nut to 15 lb.ft. Lock
the bolt and nut in position with lock-plate tabs.5. Reinstall stop bolt into steering column.
6. Full turn steering wheel both right and left. If any
resistance is noticeable, it will be necessary to remove
the sleering column and correct the cause.
D. Installation (Opel 1900. Manta)CAUTION: Fasteners are important attachingparts in
that they could affect the performance of vital com-
ponents and systems, and/or could result in
maJbrrepair 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 oflesser
quaky or substitute design.
Torque values must be used as specified during reas-
sembly to assure proper retention of these parts.
1. Prior to installation, set steering gear to high
point. The steering wheel spokes point downwards in
an oblique angle. The elongated cutout of the lower
steering mast must coincide with the clamp bolt hole
of the pinion flange.
2. Position steering gear on front suspension cross
member and torque attaching bolts to 29 lb.ft.
3. Position tie rod studs in steering arms. Install nuts
and torque to 29
Ib.ft. Lock in position with new
cotter pin.
4. Install the lower end of the steering shaft to flexi-
ble coupling and torque clamp bolt to 22
lb.ft.5. Attach guard plate to both side members and
lower deflector panel.
DISASSEMBLY AND ASSEMBLY OF
STEERING GEAR ASSEMBLY WITH TIE RODS
Disassembly - GT1. Carefully clamp gear assembly in soft jaw vise and
slip clamps and rubber bellows off gear housing to
expose area where ball joint screws into rack.
2. Bend up round edges of lockplates from tie rod
ball studs and disconnect tie rod ball studs from rack.
See Figure
3D-9). It is important that rack be held
secure with open end wrench to prevent damage to
rack teeth.
3. Loosen adjusting screw lock nut; remove adjusting
screw from steering gear housing, and take out thrust
spring and sintered bronze shell. See Figure
3D-11.4. Rotate gear assembly in vise so that pinion shaft
portion of assembly is held by vise, and remove pin-
ion nut, flat washer, and special washer.

STEERING GEAR ASSEMBLY30.33ble steering gear lubricant. Fill long end of housingbly. Under such circumstances, the bellows will be
with approximately 1 3/4 oz. steering gear lubricant.
drawn inward and jam into the rack teeth.
3. Reassemble pinion shaft into gear assembly so that
spline in pinion shaft meshes with twelfth tooth of
the rack. Use pinion mounting sleeve J-21712 during
installation of pinion shaft to avoid damage to “0”
ring in pinion bushing. When reassembling pinion
shaft into gear housing, be sure that pinion is so
positioned that bolt hole in pinion shaft flexible cou-
pling is on top and parallel to the rack. See Figure
3D-16.2. Insert long toothless end of rack into short end of
housing until rack ends (A) protrude equally out of
both ends of housing. See Figure
3D-16.Figure 3D-16
- Steering Gear Housing With Rack
Check to insure that three air channels of sintered
metal bushing are not obstructed by lubricant. If air
channels are blocked, a vacuum condition in the bel-
lows may result during operation of the gear assem-
SPECIFICATIONS
Tightening Specifications
PartLocation
BoltBolt
Nut
NutNut
Bolt
Bolt
NutNut
Nut4. Reassemble special washer, flat washer, and new
pinion nut onto pinion shaft. Torque pinion nut to 11
lb.ft. Do not exceed torque due to possibility of jam-
ming gear.
5. Place sintered bronze shell into steering gear hous-
ing and till adjusting hole with suitable steering gear
lubricant.
6. Reassemble thrust spring, adjuster screw and lock-
nut on gear assembly. Torque locknut to 43
Ib.ft.7. Screw ball stud of the axial joint together with stop
plate onto both ends of the rack. Torque to 47
lb.ft.Counterhold rack with open-end wrench.
8. Slide rubber bellows onto axial joint and steering
gear housing. Attach rubber bellows with loose
clamp and clamping wire. Check that rubber bellows
is not twisted.
FlexibleCouplingClamp(GT)
Flexible Coupling Clamp (1 900
- Manta) _....,,,,,,....._...,,,,Tie
RodBall-Connects toRack (GT). . . . . .
BallStud - Axial Joint toRack (1900 - Manta)
Tie
RodLockNut(1900-Manta). . . . . .
Steering Gear Housing to Front Suspension
Crossmember (GT)
,,....._.._.................................................Steering Gear Housing to Front Suspension
Crossmember (1 900
- Manta) _...........................,...........Adjusting Screw Lock Nut.
.._.._....................................Pinion
. . . .._............_.......,,,,,.........................................,,,,..........,,Tie Rod to Steering Arm. .
.._.....................................
Torque
Lb.Ft..-
;“2
43
4749
18
29
43
:i

REAR SUSPENSION3F- 51
REAR SUSPENSION
CONTENTS
Subject
DESCRIPTION AND OPERATION:
Description and Operation of Rear Suspension. . . . . .DIAGNOSIS: (Not Applicable)
MAINTENANCE AND ADJUSTMENTS: (Not
Applicable)
MAJOR REPAIR:
Rear Shock Absorber Removal and Replacement . .
Rear
SpringRemovalandInstallation. . . . . . . . . . . . . . . . . . . . . . . .LowerControlArmReplacement
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Stabilizer
RodReplacement. . . . . . . . . . . ~ . . . . . . . . . . . . . . . . . . . . . ..-....Track Rod Replacement
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .SPECIFICATIONS:
Rear
SuspensionSpecifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page No.3F-5
13F-513F-523F-533F-533F-533F-53
DESCRIPTION AND OPERATIONDESCRIPTION AND OPERATION OF REAR
SUSPENSIONAll Opels utilize the three link rear suspension ar-
rangement. This rear suspension consists of coil
springs, track rod, shock absorbers and lower control
arms.The coil springs set between two seats which arc
situated ahead of the rear axle housing.
The track rod is utilized on all models to control the
lateral stability of the rear axle assembly. It is of
tubular design. A stabilizer rod is used on all Wagons
as well as Fast Backs and Sedans. The GT is not
equipped with a stabilizer rod.
The lower control arms are of tubular design and
function as two links of the three link suspension
system. They are attached to the underbody through
brackets welded to the side rails and to the rear axle
assembly through the front portion of the spring seat
bracket. The lower control arms control the fore and
aft movement of the rear axle assembly.
The third link in this suspension system is the torque
tube which is connected to the differential carrier
and also to the underbody through rubber bushings
in the central joint support bracket.The torque tube in conjunction with the lower con-
trol arms absorb all acceleration and braking torque.
MAJOR REPAIR
REAR SHOCK ABSORBER REMOVALAND INSTALLATION
RemovalNOTE: The trim panel under the spare tire must be
removed on the GT to gain access to attaching nuts.
1. Remove upper attaching nut, retainer and rubber
grommet.
2. Remove lower attaching nut and rubber grommet
retainer, compress shock absorber and remove from
lower mounting pin.
Installation1. Replace upper and lower rubber grommets, if
necessary, before installing shock absorber.
2. Extend shock absorber and position in car. Attach
at lower end first, torque nut to 15 lb.ft. on the GT,
and torque to 47 lb.ft. on the Opel 1900
- Manta.

WHEELS AND TIRES3G- 61Cornering Tread WearThe modern independently-sprung automobile al-
lows the driver to negotiate turns at a high rate of
speed with a greater feeling of safety. This fact is
responsible for a comparatively new type of tread
wear that can easily be mistaken for toe or camber
wear.When a car is making a turn, the tires are supposed
to be rolling in a circle. When the turn is made at
high speed, however, centrifugal force acting on the
car causes the tires to be distorted sideways and to
slip or skid on the road surface. This produces a
diagonal cross type of wear, which in severe cases
will result in a fine or sharp edge on each rib of the
tire treads.
Cornering wear can be distinguished from toe or
camber wear by the rounding of the outside shoulder
of the tire and by the roughening of tread surface in
this section denoting severe abrasion. See Figure
3G-7.No alignment or tire pressure cahnge can be made
that will relieve cornering wear. Only the driver can
effect a cure and that is by slowing down on curves.
Heel and Toe Tread WearHeel and toe wear is a saw-tooth effect with one end
of each tread block worn more than the other.
The end which wears is the one that first grips the
road when the brakes are applied. High-speed driv-
ing and excessive “se of the brakes will cause this
type of irregular tire wear. This type of wear will
occur on any type of block tread design. See Figure3G-7.
Heel and toe wear is not so prevalent on the rear tires
because of the propelling action which creates a
counteracting force which wears the opposite end of
the tread block. These two stresses on the rear tires
wear the tread blocks in opposite directions and re-
sult in more even wear while on the front tires, the
braking stress is the only one which is effective. This
may be counteracted by interchanging tires.
A small amount of irregular wear, slightly
saw-toothed in appearance, at the outer segments of tires
is a normal condition and is due to the difference in
circumference between the center and the outer
edges of the tire tread. This saw-toothed appearance,
however, will be exaggerated by underinflation, im-
proper toe-in, or both.Cupped or Scalloped Type Tire Wear
Cupping or scalloping is associated with wear on acar driven mostly at highway speeds without recom-
mended tire rotation. Factors which promote cup-
ping include underinflation, incorrect toe-in setting
or camber setting, and steady highway speeds on
smooth, paved surfaces as opposed to gravel or
rough asphalt.
The following recommendations suggest action that
may be taken to help prevent cupping.
1. Rotate tires as recommended in Figure
3G-6.2. Frequently inspect front tires for irregular wear
due to underinflation, improper toe-in setting, or
camber setting. Regardless of the original cause of
cupped tread wear on either front tire, no alignment
or balance job, however perfect, can prevent future
excessive wear of the spots. Once a front tire acquires
flat or cupped spots, additional wear will continue at
a rapid rate. At the time of correction, however, the
cupped tire should be interchanged with a rear tire
on which the tread runs true. The cupped tire will,
to a certain degree, true itself on a rear wheel.
Although not normally the cause of cupping, the
following factors can contribute to the problem.
Looseness of parts in the suspension system, such as
worn steering knuckle ball joints, loose wheel bear-
ings, inoperative shock absorbers, and any excessive
looseness throughout the steering system all tend to
allow the front wheels to kick around and, if any of
the wheel alignment factors are incorrect, irregular
spotty tire tread wear of one type or another may
result.
Wobble or runout of a tire, either front or rear, due
to bent wheel or to tire being improperly mounted
will cause uneven wear.
MAINTENANCE AND ADJUSTMENTSDEMOUNTING AND MOUNTING
TUBELESS TIRESDue to “se of symmetrical rims, tires must be
mounted over the narrow rim shoulder i.e., over out-
side rim flange.
When demounting a tubeless tire “se care to avoid
damaging the rim-seal ridges on tire beads DO NOT
USE TIRE IRONS TO FORCE BEADS A WA Y
FROM WHEEL RIM FLANGES.
When tire is removed, inspect it carefully to deter-
mine whether loss of air was caused by puncture or
by improper
tit of beads against rim flanges. If im-
proper fit is indicated, check wheel as follows: Do
not reuse dented rims.