tires OPEL 1900 1973 User Guide

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- 59
TREAD
CONTAil WITH ROAD
I
UNDERINFLAlIONIUNDERINFLATIONTREAD CONTACT WITH ROAD
PROPER INFLATIONTREAD
CON& WI;,, ROAD
lOVERINFLATIONOVERINFLATION
DERS OF TREAD WORNCENTER OF TREAD WOI
FEATHERED EDGE
._---... .-ONE SIDE OF TREAD WORN
/SHOULDER OF TREADFINS
WORN AND SCUFFEDmROUGH
SURFACE
CORNERING WEAR
3G-7Figure 3G-7 Uneven Tire Wear

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

WHEELS AND TIRES36-63would require inflation pressures above the maximum allowable, speed must be
limited to 75 miles per hour.
3.Cool tire inflation pressure: After vehicle has been inoperative for 3 hours
or more, or driven less than one mile. Hot tire inflation pressure: After vehicle
has been driven
10 miles or more at 60-70 MPH.
4.Vehicles with luggage racks do not have a vehicle load limit greater than
specified.
5. When towing trailers, the allowable passenger and cargo load must be
reduced by an amount equal to the trailer tongue load on the trailer hitch.
Torque SpecificationWheelNuts
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65lb.ft.
IFigure 3G-8 Wheel and Tire - Exploded View

DISC BRAKES5B- 13
Condition
Possible CauseCorrection
2. Front end out of line.2. Check and align to manufac-
turer’s specifications.
3. Unmatched tires on sameaxle.3. Tires with approximately the
same amount of tread should be used
on the same axle.
4. Restricted brake tubes
or hoses.4. Check for soft hoses and damaged
lines. Replace with new hoses and
new double-walled steel brake
tubing.
5. Malfunctioning caliper
assembly.5. Frozen caliper
- check for
stuck or sluggish pistons, proper
lubrication.
6. Defective or damaged
shoe and lining (grease or
brake fluid on lining or
bent shoe).6. Install new shoe and lining in
complete axle sets.
7. Malfunctioning rear
brakes.7. Check for brake adjustment,
defective lining (grease or brake
fluid on lining) or defective wheel
cylinders. Repair as necessary.
8. Loose suspension parts.
9. Loose calipers.8. Check all suspension mountings.
9. Check and torque bolts to
specifications.
Brake Roughness or Chatter
(Pedal Pulsates)
1. Excessive lateralrunout.1. Check per instructions and
replace or machine the rotor, if not
within specifications.
2. Parallelism not within
specifications.2. Check per instructions and replace
or machine the rotor, if not within
specifications.
3. Wheel bearings not
adjusted.3. Adjust wheel bearings to correct
specifications.
4. Rear drums out of round.4. Check runout and, if not within
specifications, turn the drums within
specifications.
5. Shoe reversed (steel
against iron).5. Replace shoe and lining and
machine rotor within specifications.
ExcesGve Pedal Effort1. Malfunctioning power
brake.1. Check power brake and repair,
if necessary.

9C-110 197j 6PEi SERVICE MANUAL
c. Adjust trimmei screw for maximum volume,
d. If antenna trir&ner does not have a definite peak,
check for defective ant&ma by substitution.
2. Check that the speaker connection is plugged in
securely.3. If the radio is still weak, remove the receiver and
speaker assembly for repair.
Radio Is Noisy1. Radio is noisy all the time:
a. Check for defective antenna by striking antenna
with hand. If static is heard while tapping, replace
antenna.
b. If antenna is not defective, remove receiver and
speaker for ripair.
2. Radio is noisy only when jarred:
a. Check antenna as in Step No. 1 above.
b. Check speaker connection. If speaker connection
is not at fault, remove receiver and speaker for re-
pair.
3. Radio is noisy when engine is running:
a. Check noise suppressor by substituting on genera-
tor with known good one.
b. Check to see that antenna is mounted securely,
grounding the antenna base to the fender. The an-
tenna lead-in wire is shielded and the shield should
have good ground corinection at the receiver and the
antenna base.
c. Check for other car wiring passing too close to
radio receiver case.
d. If engine noise is still present, remove receiver and
speaker for repair.
4. Radio is noisy when car equipment is operated,
such as directional lights or brake lights:
Check for defective antenna lead-in wire or loose
antenna mounting, as in Step No. 3b above.
5. Radio is noisy only on dry days when car is mov-
ing:
Wheel and tire static will occur only during dry
weather. To check to see if noise is wheel static or tire
static, drive car until noise is noticed. Touch the
brake. If noise disappears, it is wheel static. If noise
persists, it is tire static. Static may be eliminated in
two ways:a. Wheel static may be eliminated by installation of
static collectors in the front wheels. It is important
to make sure the button on the end of the spiral
collector rides evenly in the spindle. Grease and dirt
can cause poor contact between static collector and
the cap, which would result in wheel static, even with
the collectors installed.
b. Tire static is eliminated by injecting graphite tire
static powder in all
five (5) tires. Either a special gun
or a plastic squeeze bottle can be used to insert pow-
der.MAINTENANCE AND ADJUSTMENTS
ANTENNA TRIMMER ADJUSTMENTAn antenna trimmer adjustment screw is provided
for matching of the antenna coil in the receiver to the
car antenna. This adjustment must always be made
after installation of a receiver or an antenna, or after
repair to these units. This adjustment should also be
performed whenever radio reception is unsatisfac-
tory.1. Position antenna to a height of 31 inches.
2. Tune receiver to a weak station at or near 1400
KHz that can barely be heard with volume turned
fully up.
3. Insert a small-bladed screwdriver in antenna trim-
mer screw and rotate screw until maximum volume
is achieved.
Figure 9C-15 Radio Control Knobs

Subject
Page NumbelSubjectPage Number4.Speed Manual I..
Clutch
Detent Cable Adjustment
:Differential
Directional Signal Switch
Repair Opel 1900 & Manta
Repair GT
:Disassembly of
4.Speed Manual Transmission
DistributorFunction of Valves and Hydraulic Control Units
Opel
3.Speed Automatic.................
74-21
Fuse Chart..............................lG-56
Fusible Link.............................
lA-8Specifications.
Point Replacement..
..,78-127A-
17c-9148-73E-393E-4878.23
1C-26
1 c-20
GEGas Tank See Fuel Tank
General Specifications
Engine...............................6A-28
Opel 3.Speed Automatic
.................7C-134
Transmission, Manual.,
..................78-33
Clutch...............................7A-7
Body................................ZA-4
Governor Drive Gear
Opel
3.Speed Automatic.................7C-103
Grille
Opel 1900 & Manta.....................8A-7
GT..................................8A-6 Electrically Heated Rear Window
Engine
General Description
Cooling System
Lubrication System
Trouble Diagnosis
Exhaust Manifold
Exhaust System
Removal and Installation
External Oil Leaks,
Opel 3 Speed Automatic
FFast Idle Adjustment
..................
Filter-Engine Oil
......................
Fluid Checking Procedure Transmission
Opel 3Speed Automatic.............
Frame-Opel 1900 & Manta.............
Frame
GT-Opel......................
SWVOOpel Xipeed Automatic...........
Front Suspension
Opel1900&Manta.................
GT..............................
Front Wheel Alignment................
Front Wheel Bearing Adjustment
All Series.........................
Fuel Gauge
Trouble Diagnosis
Opell$OO&Manta...............
GT............................
Fuel Pump Operation..................
Fuel System
Fuel Tank (Opel 1900 & Manta)
.......
Fuel Lines (Opel 1900 & Manta)
.......
Fuel Tank
(GT)....................
Fuel Gauge Tank Unit
(GT)...........
Fuel Lines
(GT)....................
Fuel Tank Removal and Installation....
Cleaning Tank.....................
lH-576A-268-326A-46A-66A-126D-427C-816E-51
oc-77C~Bl2B-826-77c-1003A-23A-23C-223A-4
HHazard Warning Flasher
....................lG-55
Headlamp Aiming
.........................1 F-46
Headlamp Switch
Opel 190.0 & Manta
.....................1 F-46
Headlamp Mechanism GT
..................8A-2
Heater System Opel 1900 &Manta
Trouble Diagnosis
......................9A-11
Description and Operation
................9A-10
Adjustments and Minor Service............9A-12
Removal and Installation
.................9A-12
Specifications..........................$A-16
Heater System GT
Trouble Diagnosis
......................9A-4
Description and Operation
................9A-2
Adjustments and Minor Service
............9A-4
Removal and Installation.................9A-5
Specifications..........................$A-9Horn
Operation.............................lG-54
Hydraulic Operation
Opel
3.Speed Automatic.................7C-64
IIdentification Number Vehicle...............
OA-1ldle.Adjustment
..........................6E-51
Inflation Pressures, Tires.
...................36-62
Ignition Coil
Specifications.
.........................
lC-26Identification, Engine
......................
OA-1Ignition System
Timing...............................
lC-20Instrument Panel Parts Removal

SubjectPage Number1
Throttle Linkage Adjustment........,:.......6E-51
Timing Chain Cover.......................6A-23
Timing Chain and Sprocket.........
':.......6A-23
Tires...................................36-55
Inflation.....................
.;.......3G-62
Rotation.............................36-57
Sizes.........................
........3G-62
Track Rod..............................3F-53
Transmission Oil Pan
Automatic Transmission.................7C-99
Transmission Reassembly
4 Speed Manual. 1.9.....................76-28Tranmission Removal and Installation
4 Speed Manual
Removal...........................7B-22
Installation.........................76-22
Auto&tic............................7c-94Tune’Up Procedure........................66-65
Torque Specifications. Engine...............6A-27
Turn Signal See Directional Signal
Universal Joints..........................4A-3Subject
VPage Number
Vacuum Modulator..7C-101
Valve Body Transmlssmn7C.99
Valve and Seat Reconditioning Engine6A-12
WWater Pump Engine1.9L Engine
Wheels
Wheel Alignment
Whee! Bearing, Adjustment,
Windshield Wiper and Washer:
Trouble Diagnosis:Description and Operation
Removal and Installation
Specifications
Wiring Diagrams Complete
Opel 1900 ._.
Manta
GT
1 E-37
1 E-37
1 E-38
1 E-43
1 J-l 03
1 J-l 05lJ-10768-3436-553C-223A-4