brake OPEL 1900 1973 Owner's Manual

FRONT SUSPENSION3A- 13
6. Reconnect shock absorber to lower control arm
and torque to 30
Ib.ft.7. Remove spring compressor.
8. Install front wheel, and lower the car.
9. Check front end alignment.
Installation Opel 1900 Manta
CAUTION: Fasteners are important attachingparts in
that they could aff&
the-performance of vitaI com-
ponents and systems, and/or could
resu/t in major
repair expenses. They must be
repraced with one of
the same part number or with an
equivaknt part, ifreplacement becomes necessary. Do not use a re-
placement part of ksser quality or substitute design.
Torque values must be used as specified
dmitig reas-
sembIy to assure proper retention of these parts.1. Loosely attach lower control arm to front cross
member.
2. Properly seat spring between lower control arm
and cross member.
3. Raise jack and place lower control into position.
4. Attach lower control ball joint to steering knuckle
and torque nut to 54
Ib.ft.5. Tighten lower control arm to cross member bolt
to 43
lb.ft.6. Attach stabilizer bar to lower control arm and
torque to 87
lb.ft.7. Attach stabilizer bar to cross member to body
support.
8. Install shock absorber and torque lower attaching
nut and bolt to 30
lb.ft.9. Install nuts on upper shock absorber attaching
studs. Tighten nuts until a distance from top of nut
to stud is approximately
l/2 inch.
10. Install front wheels and tighten nuts to 65
lb.ft.11. Remove stands and lower car.
STEERING KNUCKLE REMOVAL AND
INSTALLATION
Removal GT1. Raise car and support with stands.
2. Remove wheel nuts. Remove wheel assembly.
Figure 3A-2 1 Caliper Attachment4. Remove spindle grease cap. Remove cotter pin
and spindle nut. Remove wheel hub with disc.
5. Install J-21689 spring compressor and compress
spring until 3-l/8” clearance is obtained between
spring compressor and lower spring leaf.
6. Remove upper ball joint using tie rod remover,
J-
21687.7. Remove shock absorber at lower attachment only.
8. Remove lower ball joint using J-21687 remover
and remove steering knuckle. Remove dust shield
from steering knuckle.
Removal Opel 1900. Manta1. Raise car and support with stands.
2. Detach brake caliper and steering arm from steer-
ing knuckle.
3. Remove castle nut cotter pin, unscrew nut and
pull steering knuckle off upper control arm ball joint.
4. Unscrew brake caliper and suspend it in wheel
house.5. Remove front wheel hub.
6. Unscrew steering arm and brake cover plate from

3A. 141973 OPEL SERVkE MANUAL
Figure 3A-22 Caliper Removed and Hung by Wire
steering knuckle. Swing steering arm and tie rod to
the side.7. Remove castle nut cotter pin, unscrew nut and
pull steering knuckle off lower control arm ball joint.
Installation GTCAUTION: Fasteners are important attachingparts in
that they could affect the performance of
viral 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
desig.Torque values must be used as specified during reas-
sembly to assure proper retention of these parts.
1. Always replace paper gasket when installing dust
shield on steering knuckle. Lightly coat both surfaces
of paper gasket with chassis lubricant before installa-tion and torque attaching bolts to 47
lb.ft.2. Install lower ball joint in steering knuckle. Torque
castle nut to 54
Ib.ft. Install new cotter pin.
3. Attach shock absorber at lower end. Torque boltsto 30 lbs. ft.
4. Install upper ball joint. Torque castle nut to 29
lb.ft. Install new cotter pin.
5. Remove spring compressor.6. Install hub and disc on spindle and tighten spindle
nut as stated under MAINTENANCE AND AD-
JUSTMENTS in this section.
7. Install caliper on steering knuckle and torque boltsto 72
lb.ft. See Figure 3A-21.8. Install wheel and torque wheel nuts to 65
lb.ft.
Installation Opel 1900
- MantaCAUTION: Fasteners are important attachingparts in
that they could
affit the performance of vital com-
ponents and systems, and/or could result in
ma&repair expense. They must be replaced with one of
the same part number or with equivalent parts, ifrepfacement 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. Attach steering knuckle to lower control arm ball
joint. Torque castle nut to 54
lb.ft.
2.
Atl,ach brake cover plate and steering arm to steer-ing knuckle. If required, install new paper gasket
between cover plate and steering knuckle. Care for
proper seat of T-head bolts. See Figure
3A-23.Figure 3A-23 Attaching Brake Cover Plate
3. Install front wheel hub and brake caliper.
4. Attach steering knuckle to upper control arm ball
joint. Torque castle nut to 40
lb.ft.5. Steering arm to steering knuckle
_ 58 lb.ft.6. Brake caliper to steering knuckle
- 72 lb.ft.7. Adjust front wheel bearing clearance.
8. Remove stands and lower car

3A- 161973 OPEL SERVICE MANUAL
SPECIFICATIONS
Torque Specifications
Use a reliable torque wrench to tighten all parts listed to insure proper
tightness without straining or distorting parts. These specifications are for
clean and lightly-lubricated threads only; dry or dirty threads produce in-
creased friction which prevents accurate maasurement of tightness.
LocationFront Suspension Crossmember to Front Frame
Clamp, Steering Mast to Steering Mast Flange
(GT)
........................................................................................
Clamp, Steering Mast to Steering Mast Flange(1900
-Manta)..................................................................
Clamp,UpperUniversalJoint(GT)..................................Clamp, Lower Universal Joint (GT)
..................................
WheelNuts............................................................................Lower Control Arm Shaft to Lower Control Arm
..........Lower Control Arm Ball Joint to Steering Knuckle
......Upper Control Arm Ball Joint to Steering Knuckle
(GT)........................................................................................Upper Control Arm Ball Joint to Steering Knuckle
(1 900 Manta)
..................................................................Upper Control Arm Ball Joint to Upper Control Arm
ShockAbsorbertoLowerControlArm..........................Steering Arm to Steering Knuckle (1900
- Manta)......
Brake Backing Plate or Brake Disc Shield andSteering Arm to Steering Knuckle
(GTJ
Hex Head Bolt M 10......Hex Head Bolt M 8
......
Brake Backing Plate to Steering Knuckle(1900 Manta)
..................................................................
Brake Caliper to Steering Knuckle.................................
Lower Control Arm to Front Spring Eye (GT)................
Brake Disc to Front Wheel Hub........................................Upper Control Arm to Crossmember (1900
- MantajLower Control Arm to Crossmember (1900
- Manta)
Steering Gear Housing to Front Suspension
Crossmember (GT)
............................................................
Steering Gear Housing to Front SuspensionCrossmember (1900
- Manta)........................................Stabilizer Bar to Lower Control Arm
(Opel 1900
- Manta)........................................................Tie Rod Clamp Bolts
(GTJ....................................................
CastleNut,TieRodtoSteeringArm..............................Upper Control Arm Shaft to Shock Absorber Support
and Upper Control Arm (GT)
..........................................
CrossMember to
BodySupport Attachment................
FrontSuspensionAssemblytoFrame............................Front End Alignment Specifications
Torque
Lb.Ft.36
1522
14
22
6540
5429
ii30
5847
18
58
72
1836
40
43
1830
87
:i33
58
47ModelCaster’
Camber”1900‘3
l/2-6 l/2GT
3+1-:%+*Permissible deviation from left to right wheel
- Max. 1’.
Toe-In”Min.-Max.
l/8-3/ 16
l/32-1/8Outer Wheel
When Inner
Wheel at 20
19
l/418
l/2

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

3G- 561973 OPEL SERVICE MANUAL
parking brake cable. Spin the other wheel using the
same procedure.
By spinning the wheels, the offending tire will cause
vibration that may be felt by touching the bumper or
fender. By the process of elimination, proceed on
STATIC UNBALANCEDYNAMIC UNBALANCE‘\I....;,’30-i
Figure 3G-2 Static and Dynamic Unbalancetires that cause vibration as follows:
UnbalanceCheck for tire/wheel unbalance An unbalanced
wheel assembly that is causing a vibration can, in
most cases, be reduced to an acceptable level by
static and dynamic wheel and hub balancing. Correct
by rebalancing, Figure
3G-2. It is recommended that
an on-the-car balancer be used for balancing.
A tire/wheel assembly that is in balance may still be
causing a vibration when the car is driven, but may
not set up a vibration when the wheel is off the
ground and submitted to the spinner test. In such
cases, the next step is to check radial and lateralrunout.
RunoutA runout gauge should be used to determine the
amount of total radial and lateral runout at the tire
that causes the vibration. See Figures
3G-3 and
3G-4.A guide to runout maximum totals is as follows:
,035 inch Radial - Wheel
,050 inch Radial - Tire/Wheel Assembly
,045 inch Lateral - Wheel
Figure 3G-3 Checking Radial
Runout

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

36. 601973 OPEL SERVICE MANUAL
severe or careless driver. Rapid acceleration and de-celeration, severe application of brakes, taking turns
at excessive speed, high-speed driving, and striking
curbs or other obstructions which lead to misalign-
ment are driving habits which will shorten the life of
any tire.hiaintenance of proper inflation pressure and peri-
odic interchanging of tires to equalize wear are
within the control of the driver. Underinflation
raises the internal temperature of a tire greatly due
to the continual friction caused by the flexing of the
side walls. Tire squealing on turns is an indication of
underinflation or excessive speed on the turns. A
combination of underinflation, high road tempera-
tures, and high-speed driving will quickly ruin the
best tire made.
High speed on straight highways or expressways nor-
mally causes more rapid wear on the rear than on thefront tires, although cupping of front tires can result
if the tires are not periodically switched from wheel
to wheel. Driving turns and curves at too high a rate
of speed causes the front tires to wear much faster
than the rear tires.
An inspection of the tires, together with information
as to locality in which the car has been operated willusually indicate whether abnormal wear is due to the
operating conditions described above or to mechani-cal faults which should be corrected.
The various types of
abnormal tire wear and their
causes are described in the following paragraphs.
Shoulder or Underinflation Tread WearWhen a tire is underinflated, the side walls and
shoulders of the tread carry the load, while the centerof tread folds in or compresses due to the low inter-
nal air pressure. This action causes the shoulders to
take all of the driving and braking load, resulting in
much faster wear of shoulders than of the center of
tread. See Figure 3G-7. For maximum results in han-dling, riding and tire life, tire inflation pressures
should never be allowed to go below the specified
minimum pressure.
Continuous high-speed driving on curves, right and
left, may produce tread wear very similar to underin-flation wear and might very easily be mistaken for
such. Side thrust when rounding turns causes wear
on the sides of tire tread. In making a turn to the left,especially at high speeds, the outside shoulder of the
right tire and the inside shoulder of the left tire take
the side thrust and naturally receive the most wear.
The only possible correction is to advise slower
speeds on curves. Do not increase tire inflation pres-
sures beyond specified limits, as this will cause centeror over-inflation wear. See paragraph below.
Canter or Overinflation Tread Wear
Excessive wheel camber, either positive or negative,causes the tire to run at such an angle to the road
surface that one side of the tread wears much more
than the other. See Figure
3G-7.When tire inflation pressures are maintained within
the specified limits, the tire will make a full contact
across the entire width of tread, thereby distributing
the wear evenly over the total surface of the tread
area.
Cross or Toe Tread WearWhen the front wheels have an excessive amount of
either toe-in or toe-out, the tires are actually draggedsideways when they travel straight down the road
and cross wear or scraping action takes place rapidly
wearing away the tread of tires. This cross wear con-dition will usually produce a tapered or feathered
edge on the ribs of the tire tread. See Figure
3G-7.In most cases, this can be detected by rubbing the
hand across the tire tread.
If the tapered or feathered edges are on the inner
sides of the ribs on one of both sides, it indicates thatone or both tires have excessive toe-in, while the
same condition in the outer sides of ribs indicates
excessive toe-out. Usually, excessive toe-in causes
excessive tire wear on the outer edge of the right
front tire and toe-out causes tire wear on the inner
edge of the left front tire. See Section 3C for toe-in
correction.Cornering wear caused by high-speed driving on
curves (see following paragraph) sometimes has the
appearance of toe wear. Care must be used to distin-guish between these two types of wear so that the
proper corrective measures will be used.
Side or Camber WearExcessive wheel camber, either positive or negative,
causes the tire to run at such an angle to the road
surface that one side of the tread wears much more
than the other. See Figure
3G-7.The amount or angle of the camber wear will be
governed by the amount of positive or negative cam-ber. Tire tread wear very similar in appearance to
camber wear may be caused by driving on turns at
excessive speeds. This “cornering” tread wear (see
paragraph below) cannot be corrected by change of
camber angle.
Adjustments for specified camber are covered in Sec-
tion 3C.

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.

3G- 621973 OPEL SERVICE MANUAL
1. Clean rims thoroughly, using No. 3 coarse steel
wool to remove all oxidized rubber, soap solution,
etc. Remove rust with wire brush.2. Inspect butt weld and other areas of rim contactedby tire beads to make certain there is no groove or
high spot. Remove any groove or high spot by tiling
smooth.
3. Inspect valve stem and replace it if damaged.
Make certain that valve stem is properly installed to
provide an air tight joint.
4. Before mounting a tubeless tire on a wheel, mois-
ten a cloth with mounting compound or soap solu-
tion and wipe rim-seal ridges of both beads to remove
all foreign substances.
5. Moisten base of both beads with mounting com-
pound or soap solution to help beads snap into place
when tire is inflated. Start tire over rim flange at
point opposite valve stem.
6. Inflate tire until both beads are firmly seated
against rim flanges and temporarily over inflate.
Leak test wheel and tire assembly and if satisfactory,
reduce to recommended pressure.
SPECIFICATIONSWHEEL AND TIRE BALANCE
Wheel and tire balance is the equal distribution of the
weight of the wheel and tire assembly around the axis
of rotation. Wheel unbalance is the principal cause of
tramp and general car shake and roughness and con-
tributes somewhat to steering troubles.
The original balance of the tire and wheel assembly
may change as the tire wears. Severe acceleration,
severe brake applications, fast cornering and side slip
wear the tires out in spots and often upset the origi-
nal balance condition and make it desirable to rebal-
ance the tire and wheel as an assembly. Tire and
wheel assemblies should be rebalanced after punc-
tures are repaired.
Because of the speed at which cars are driven, it is
necessary to test the wheel and tire assembly for
dynamic balance. Dynamic balancing of a wheel and
tire assembly must be done on a machine designed to
indicate out-of-balance conditions while the wheel is
rotating on the car. Since procedures differ with dif-
ferent machines, the instructions of the equipment
manufacturer must be carefully followed.
General SpecificationsWheels
Opel 1900
- Manta and GT ,._......,,,._.................,...,,..............................~,,,.................... 5.J x 13
Tires
1900 - Manta __.......,,___.,...,,..,.....,,....,,...........,...,,.,,...,.........,,..................,....................... 165-13
GT . . . . . . . ..__........_..............,...,,........,,,...,,..........,....,..,,...,,........,..................,,,.....................165-13
Tire Size and Pressures (Pounds Per Square Inch
Cold)
ModelTire Size51.53.54.57
165-1357R.57L165-13
77
165-13Recommended(Standard
PressureInflation)
FrontRear24
PSI32PSI23
PSI26PSI
19PSI23
PSI
NOTE:
1.Tire inflation pressures may increase as much as 6 pounds per square inch
when hot.
2.For continuous high-speed operation (over 75 MPH), increase tire inflation
pressures 4 pounds per square inch over the recommended pressures up to a
maximum of 30 pounds per square inch cool for 4 ply rating tires. When the
4 psi pressure adjustment for sustained high speed with maximum vehicle load