ABS OPEL 1900 1973 Owner's Guide

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.

3F. 521973 OPEL SERVICE MANUAL
3. Install rubber grommet, retainer and self-locking
nut at top of shock absorber. Torque to 10 lb. ft.
Always use new self-locking nuts.
REAR SPRING REMOVAL AND INSTALLATION
Rear Spring Removal1. Raise rear of car with floor jack under differential
carrier and support with jack stands positioned un-
der side jack brackets. See Figure
3F-2.Figure 3F-3 Removing Coil
SpringFigure 3F-2 Raising Rear of Car
2. Remove rear wheels.3. Disconnect shock absorbers from rear axle.
4. Disconnect stabilizer and shackles, if equipped,
from frame.
5. Lower rear axle assembly as far as possible withoutputting the brake hose under stress.
6. If necessary, tilt the rear axle assembly to remove
springs. See Figure
3F-3. Note the upper and lower
rubber damper rings.
Rear Spring Installation
1. Make certain the lower damper rings are properly
positioned in the spring seats and position the springsin their respective position in the damper rings. See
Figure
3F-4.2. Properly install upper damper rings on springs.
CAUTION: Fasteners are important attaching parts in
that they could affect the performance of vital corn-
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
qua/ity or substitute designFigure 3F-4 Installing Coil Spring
Torque values must be used as specitied during reas-
sembly to assure proper retention of these parts.3. Raise rear axle assembly to compress springs in
their seats.
4. Attach shock absorbers and tighten retaining nuts
to 15 Ib.ft. For the GT and 47 lb.ft. for the Opel 1900
- Manta.
5. Attach stabilizer shackles, if equipped, to axle
brackets and tighten bolts to 25 lb. ft. with vehicle at
curb weight.
6. Install rear wheels torquing lug nuts to 65 lb.ft.

REAR SUSPENSION3F- 53
7. Remove jack stands.
LOWER CONTROL ARM REPLACEMENTRemovalThis operation can be performed with the vehicle
standing at curb height or elevated.
1. Disconnect parking brake cable from support
bracket on control arm.
2. Loosen and remove front and rear control arm
attaching bolts and remove control arm.
installation1. On
1900’s and Manta’s place a load of approxi-
mately 350 lbs. in luggage compartment or on the
GT, place a load of approximately 150
Ibs. on dri-
ver’s seat. Torque control arm attaching nut and
bolts to 18 lb.ft on
GT’s and 23 Ib.ft. on the 1900 -Manta.
2. Connect parking brake cable to support bracket on
control
ranI.
STABILIZER ROD REPLACEMENT
Removal1. Raise and support rear of vehicle.
2. Disconnect stabilizer rod to shackle bolts.
3. Disconnect stabilizer rod to underbody retainers
and work stabilizer rod out from under vehicle.
SPECIFICATIONS
REAR SUSPENSION SPECIFICATIONS
Tightening SpecificationsInstallation1. Work stabilizer rod into position and loosely at-
tach stabilizer to underbody retainers.
2. Connect stabilizer rod to shackles.
3. With the vehicle standing on its wheels or the rear
axle assembly lifted, tighten stabilizer rod to under-
body bracket bolts to 15 lb. ft.
4. Remove jack stands and lower vehicle.
TRACK ROD REPLACEMENT
Removal1. Lift rear of car and suitably support.
2. Disconnect track rod from rear axle and frame
side member.
Installation
1. Loosely connect track rod first to side member and
then to the rear axle.
2. On the
1900 - Manta, load luggage compartment
of vehicle with approximately 350 lbs. or on the GT,
place a load of approximately 150 lbs. on driver’s
seat and tighten track rod attaching bolts to specified
torque.
3. Remove supports (jack stands) and lower vehicle.
Use a reliable torque wrench. Specifications are for clean and lightly-oiled
threads.
Part
Nut
Nut
Nut
Bolt
Nut
Nut
Nut
BoltName
WheelNuts.
.._.._......._........................................................
Control Arm Attaching (GT) .._.._.,,,........,,.,,.......,,......,,,,......
Control Arm Attaching (1 900 - Manta) .,,...._...,,,,_.....,,.,...
Stabilizer Rod to Underbody Retainers ,....._.,.,,.,.....,,,....
Shock Absorber Lower Attachment (GT) . .._.....,._.._.,,,...
Shock Absorber Lower Attachment (1900 Manta) ,,.,
Shock Absorber Upper Attachment. .._.....................
Stabilizer Shackle to Axle Bracket .._._.._,...._..,,.,,.......,,,...
Torque
Lb.Ft.
65
16
23
15
1,5
47
1025

3F- 541973 OPEL SERVICE MANUAL/UPPER RUBBER
DAMPER
RINGCOIL SPRINGTRACK ROD
LOWER RUBBER
’DAMPER RING
REAR AX;E ASSEMBLY
COIL SPRING SEAT
STABILIZER ROD
$3SHOCK ABSORBER
LOWER CONTROLARM
Figure 3F.5 Exploded View Rear Suspension

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.

REAR AXLE
CONTENTS
SubjectPage No.
DESCRIPTION AND OPERATION:
Rear Axle Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4B- 7
DIAGNOSIS:
RearAxleTroubleDiagnosis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4B- 8
MAINTENANCE AND ADJUSTMENTS: (Not Applicale)
MAJOR REPAIR:
Removal and Installation of Rear Axle Assembly
Removal and Installation of Axle Shaft Assembly
Disassembly and Assembly of Differential
.* . . . . . . . . . . . .SPECIFICATIONS:
DifferentialSpecifications
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4B- 94B-10
48-l 1
4B-22
DESCRIPTION AND OPERATION
REAR AXLE DESCRIPTIONThe Opel rear axle is a semi-floating type that carries
car weight through the axle shafts by way of ball
bearings which are located on the outer ends of each
axle shaft. The rear axle assembly is attached to the
under body by way of the shock absorbers, track rod,
central joint support, and lower control arms. A sta-
bilizer rod is used on all Wagons, as well as Fast
Backs and Sedans. The GT is not equipped with a
stabilizer rod. The rear springs have a progressive
spring rate which is attained by a gradual reduction
of coil thickness. The springs are arranged between
the spring seats welded onto the rear axle tubes and
the under body side members. The upper and lower
ends are seated in profiled rubber dampening rings.
The differential housing is a malleable iron casting
with tubular axle housings pressed into the sides to
form a complete assembly. An oil feed passage to the
pinion bearings and an oil return hole are provided
to allow lubricant to circulate. A removable steel
cover is bolted on the rear of the differential housing
to permit service of the differential without removing
the rear axle assembly from the vehicle. A breather
fitting is located on top of the right axle tube.Within the differential carrier, the differential case is
supported by two tapered roller side bearings. These
side bearings are preloaded by shims located between
the bearing inner races and differential case. During
installation, varying the shim thickness from side to
side also determines the ring gear to pinion backlash.
The differential case houses two side gears meshed
with two pinions. The pinions and side gears are
backed by thrust washers. The pinion gears are held
in place by a pinion shaft which is anchored in the
differential case by a lock pin.
The inner end of the axle shafts engage and extend
through the splines of the side gears with a floating
tit.
The axle shafts have an enlarged diameter from mid-
shaft to the flange end.
A ball bearing and oil seal are used on all models, and
are pressed onto the outer end of the axle shaft as an
assembly.The drive pinion is mounted in two roller bearings in
the rear axle housing. Pinion setting is established by
shims located between the differential carrier and therear’pinion bearing outer race.

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

4B- 101973 OPEL SERVICE MANUAL
Figure 48-Z Removing Rear Axle Assemblyan equiva/entpart ifreplacement becomes necessary.
Do not use a replacement
part of lesser quality or
substitute design. Torque
values must be used as
specified
during reassembly to assure proper reten-
tion of these parts.1. Roll rear axle assembly under car on floor jack and
loosely attach lower control arms to rear axle hous-
ing.
2. Attach central joint support, to underbody with
bolts only finger tight.
3. Lower rear axle assembly, install lower damper
rings in spring seats, coil springs and upper damper
rings on springs. Make certain the damper rings and
springs are properly positioned.
4. Install track rod on axle housing.
5. On Opel 1900 and Manta, place a load of approxi-
mately 350
Ibs. in luggage conipartment or on the
GT, place a load of approximately 150 lbs. on drivers
seat and raise rear axle far enough for underbody to
clear jack stands.
6. Torque central joint support t$ underbody bolts to
36 lb.ft.
7. Torque lower control arm to
Axle housing bolts to
18
Ib.ft. on the GT and 22 lb.ft. dn the Opel 1900 and
Manta.
8. Torque track rod to rear axle attaching nut to
40lb.ft. on the GT and to 76
lb.ft. on the Opel 1900 and
Manta and remove added weight.
9. Install shock abosrbers and tighten nuts to 15
Ib.ft.on the GT and to 47
Ib.ft. on the Opel 1900 and
Manta.10. If car is equipped with stabilizer rod, connect
shackles to axle housing. Tighten to 25 lb. ft.
11. Connect brake hose to brake pipe and install
retaining clip.
12. Thread parking brake cable over exhaust system
and connect to lower control arm brackets, parking
brake actuating lever and brake backing plate. Install
brake drum.
13. Align mating marks and connect propeller shaft
to pinion flange. Tighten universal joint attaching
bolts to 11
Ib.ft. Bend respective lock plate tabs to
secure nuts or bolts.
14. Connect parking brake cable equalizer and return
spring to brake rod and adjust to specifications.
15. Bleed rear brake system and fill master cylinder.
16. Install wheel assemblies and tighten lug nuts to
65
lb.ft.17. Remove jack stands and lower car to the floor.
REMOVAL AND INSTALLATION OF AXLE SHAFT
ASSEMBLY
Removal1. Raise and support rear of car at jack brackets.
2. Remove wheel and brake drum as necessary.
3. Unscrew rear axle shaft retaining plate and with
axle shaft puller J-8805 coupled with slide hammer
J- 2619 on axle shaft flange, remove axle shaft.
4. For replacement of the bearing parts, first remove
retaining ring by cutting off with a chisel. See Figure4B-3.
5. Press off bearing, using rear pinion bearing
remover J-22912.
Installation
CAUTION: Fasteners in the following steps b are im-
portant attaching parts in that they could at&t
tee
performance of vital components and systems, and-
/or could result in major
repair expense.They must
be replaced with one of the same part number or with
an equivalentpart ifreplacement becomes necessary.
Do not use a replacement part of lesser quality or
substitute design Torque values must be used as
specified
during reassembly to assure proper reten-
tion of these parts.1. Check radial runout of axle shaft at ball bearing

REAR AXLE40- 11
Figure
48-3 Removing Axle Bearing Retaining Ring
seat and lateral runout of axle shaft flange near larg
est diameter.
Permissible radial runout is .002”, and permissible
“lateral runout is
.OO4”. An axle shaft which exceeds
these tolerances, or one which has been otherwise
damaged during removal, must be replaced.
2. Using installer ring J-21721-2, press on bearing so
that oil seal groove on bearing faces shaft splines.
3. Using installer ring J-21721-2, press on retainer
ring so that shoulder faces bearing.
Figure 48.4 Measuring for Axle Shaft Bearing Depth4. Check axle shafts end play as follows:
a. Using a depth gauge, measure depth of rear axle
bearing seat in axle housing (backing plate and gas-
kets in place). See Figure
4B-4.b. Measure width of bearing outer race. The differ-
ence between the two measurements indicates the
required thickness of the shims. The maximum per-
missible end play is .002”. If necessary to reduce end
play, add
,004” shims behind bearing as necessary. A
slight crush fit (up to ,006”) is desirable.
5. Coat rear axle shaft splines with hypoid gear lubri-
cant prior to installation.
6. Insert axle shaft into housing; using a mallet, drive
axle shaft completely into housing.
7. Install lock washers and nuts. Torque to 20
Ib.ft.8. Install brake drum and wheel assembly.
9. Remove supports and lower rear of car to floor.
DISASSEMBLY AND ASSEMBLY OF THE
DIFFERENTIALRemoval and installation of parts for service de-
scribed in the following sub-paragraph can be per-
formed with the rear axle assembly in the car. The
car must be raised and adequately supported to per-
mit access to the parts to be serviced.
Removal and Disassembly of Differential Case1. With car suitably supported at rear jack bracket
on each side, remove differential cover bolts and let
lubricant drain into suitable container.
2. Disconnect left end of track rod and wire to left
shock absorber.
3. Remove both rear wheels and brake drums.
4. Working through access holes in axle shaft flange,
remove four nuts and washers that retain the axle
shaft dust shield and brake backing plate to the axle
housing.
5. Unscrew rear axle shaft retaining plate.
6. Install axle shaft puller J-8805 coupled with slide
hammer J-2619 on axle shaft flange to remove rear
axle. In removing axle shaft, care should be exercised
to avoid damage to the oil seal. See Figure
4B-5.7. Remove differential cover and discard gasket.
8. Check and record ring gear backlash.

5A- 61973 OPEL SERVICE MANUAL
ing on dusty and sandy roads - the filter and sound
deadener should occasionally be replaced. To do so,
brake booster has to be removed without detaching
brake master cylinder.
Proceed as follows:
1. Remove protective cap (boot).
2. On the GT only, pry retainer from housing
using a screwdriver. See Figure
SA-6.Figure 5A-6 Brake Booster Filter (GT)
3. With a pointed tool remove air silencer and filter
out of control housing bore and pull it off thrust rod.
4. Install new filter and air silencer. On the GT, the
smooth side of the filter must face towards the inside.
The radial slots in filter and deadener must be stag-
gered to each other by 180 degrees.
5. Slide retainer over control housing (GT only) and
seal it with light plastic hammer strokes. Slide pro-
tective cap over control housing and slip it onto
brake booster housing.
VACUUM CONTROL VALVE SERVICE
A vacuum control valve is installed into the vacuum
hose between intake manifold and brake booster. It
serves to prevent air from flowing back (vacuum
release), when engine is shut off.
The vacuum control valve cannot be disassembled
and has to be replaced, if defective. On replacement,
note the following:
1. The vacuum control valve should be located near
the intake manifold. Therefore, the short vacuumhose has to be installed between intake manifold and
vacuum control valve and the long hose between
vacuum control valve and brake booster.
2. The arrows on the vacuum control valve housing
must point towards the intake manifold, otherwise
no air can be drawn out of the brake booster which
renders the brake booster ineffective.
3. The connections of the vacuum hoses to the intake
manifold, vacuum control valve and brake booster
must be airtight. For this reason make sure. that the
hose clamps are properly installed.
MAJOR REPAIR
BRAKE BOOSTER REMOVALAND INSTALLATION
Removal
1. Disconnect brake pipes from master cylinder.
Place a cloth under the master cylinder and brake
pipes to absorb any brake fluid drippings.
2. Disconnect vacuum hose from brake booster.
3. Remove four nuts and washers attaching brake
booster to brake booster support.
4. On the GT only, remove master cylinder support
to fender skirt bolts.
5. On the GT, loosen thrust rod lock nut and un-
screw the piston push rod while holding the master
cylinder brake booster assembly. On the Opel
1900and Manta, remove the nut and bolt attaching clevis
on the pedal.
6. Remove assembly from car.
7. Disconnect master cylinder from brake booster.
Installation
CAUTION: Fasteners in the folkwing steps are im-
portant attaching parts in that they could affect the
performance of vital components and systems, and-
/or could result in major repair expense. They must
berep/aced, with one of the same part number or with
an equivalent part if replacement becomes necessary.
Do not
use a replacement part or lesser quality or
substitute design. Torque values must be used as
specified during reassembly to assure proper reten-
tion of these parts.1. Using a new front housing seal, assemble master