1973 OPEL GT-R light

GT STEERING COLUMN ASSEMBLY3E- 47
2. Disconnect ignition (white) wire set plug.
3. Remove steering lock retaining screw. See Figure3E-20.Figure 3E-20 Steering Lock Retaining Screw
4. Remove direction signal switch lever.
5. Remove three screws securing signal switch cover
to housing.
6. To remove housing cover, (a) pull cover toward
direction signal switch and move it slightly to the
right. See Figure
3E-21. (b) Turn cover toward the
left and move it further to the right so that the left
retaining screw ear is positioned under the left signal
switch return cam. See Figure
3E-22. (c) Insert direc-
Figure 3E-2 1tion signal switch lever into oblong opening in cover
and push steering lock into housing and remove
cover. See Figure
3E-37.Figure
3E-22Figure 3E.23
7. Remove ignition switch electrical unit. See Figure3B24.
8. Remove wires from connector plug making certain
to note location of each.
9. Tape wire ends together and remove electrical unit
and wire harness.
Installation1. Position electrical unit wire harness through col-
umn and reconnect to connector plug.

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

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

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.

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

4A- 61973 OPEL SERVICE MANUAL
SPECIFICATIONSPROPELLER SHAFT AND CENTRAL JOINT
SPECIFICATIONS
Tightening Specifications ~
Use a reliable to’rque wrench. Specifications are for clean and lightly-oiled
threads.
Part
Bolt
Bolt
BoltTorque
BoltLocation
Drive Pinion Extension Shaft Flange to Universal
Joint
.._.....................................................................Central Joint Support to Underbody
_.._....._........._..........CentralJointSupport toRubber Cushion
Tube Rubber Cushion to Torque Tube
._.........._...............Support
CushionTorque
Lb.Ft.
1136
15

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.

REAR AXLE49.23
Adjusting end Fitting SpecificationsPinionBearingPreloadWith
NewBearings. . . . . . . . . . . . . . . . . . . . . . . . . .7-13Lb.In.
Preload With Reused Bearings
__.._..I...................,.................,,...................,,............ 5-8 Lb.In.
Pinion Depth Setting
.002” to -.OOl’ from pinion marking using following selective shims:
Number of Notches
Thickness In.in Circumference.0097Flattened on One Side
.00980
.01081
.01182
.01283
.01384
.01485Clearance Between Differential Side Gears and Case Max.
,000” on the Opel 1900 andManta and
,006” on the GT using the following selective shims:
Thickness In.
1900
,039.04
1,043,045,047,049.05
1,053,055
GT
.0394
.0433
.0473Number of Notches
in Circumference
0
1
2
.05123Max. Permissible Axle Shaft Bearing Seat Radial Runout
.._......................................... ,002”Max. Permissible Rear Axle Shaft Flanze Lateral Runout . .
,004” at Lareest Flange Dia.
Max.Permissible Lateral Ring Gear R&out
._.._,,.........._.....,........................... T . . . . . . . . . . . ...” ,003”RingGearandDrivePinionBacklash
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .,004”-.008”
Differential Side Bearing Preload New, Bearings
- 20-30 Lb.In.; Used Bearings - lo-20Lb.In., using following selective shims:
Thickness In..0059.0069
.0079
.0089
.0098
.0108
.0197
.0433Number of Notches
in Circumference
0
1
;
4
5
8
7
Torque SpecificationsUse a reliable torque wrench. Specifications are for clean and lightly-oiled
threads.