1973 OPEL MANTA ESP

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.

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

PROPELLER SHAFT AND CENTRAL JOINT4A- 5
1. Check condition of support cushions. If new cush-
ions are installed, torque to 29 lb. ft. See Figure 4A-6.
2. Install ball bearing into rubber cushion with the
flange facing toward front of car. Pack area in front
of bearing with water resistant grease. See Figure4A-7.
GAP BETWEEN BALL BEARING
AND SHEET METAL CASING
FILLED WITH GREASE
RUBBER CUSHION
BALL BEARING
TRAL JOINT
SUPPORT
RQUE TUBEa.7
Figure 4A-7 Torque Tube Bearing Installed
3. Install support bracket onto torque tube in such a
manner that one cushion is in place, then pry the
other cushion into place with a screwdriver. Torque
attaching bolts to 15 lb. ft.
4. Install drive pinion extension shaft into torque
tube from the rear. Tap in place with soft face mallet.
5. Install flange. Tap-flange onto drive pinion exten-
sion shaft, with a soft face mallet, at least far enough
to install nut.
6. Assemble flange holder J-8614 to flange, install
new self-locking nut and torque to 87
lb.ft.7. Install torque tube assembly onto differential car-
rier using only three of the four bolts. The fourth bolt
will be used later to install the brake pipe bracket.Figure
4A-8 Installing Support Bracket on TorquelTube8. Position floor jack under torque tube and raise it
far enough to install central joint support to under-
body bolts finger tight. Remove jack.
9. Jounce rear of car so springs will assume normal
position and torque the central joint support to un-
derbody bolts to 36 lb. ft.
10. Align mating marks of universal joint and flange,
connect universal joint to flange with respective bolts
and lock plates. Torque nuts to 11 lb. ft. Bend lock .
plate tangs to retain bolts.
11. Assemble parking brake cable equalizer and re-
turn spring to brake rod and adjust to specifications.
12. Connect brake line bracket to torque tube.
13. Remove supports
f&n rear of car and lower to
the floor.

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

46. 141973 OPEL SERVICE MANUAL
2. Install rear pinion bearing outer race (without
shims) using installer J-7818 and driver handle
J-8092. See Figure 4B-12.
3. To determine the correct pinion depth setting use
the following procedures:
a. Assemble gauge plate J-21691-4, rear pinion bear-
ing (lubricated), stud J-21691-7, front pinion bearing
(lubricated), pilot washer J-21691-5 and nut into dif-
ferential carrier. See Figure 4B-13.
‘1GAUGING ARBOR
Figure 48-l 3 Pinion Depth Gauging Tools Installed
b. Alternately tighten and rotate until a torque of
7-12 lb.in. (9 Ibin. desired) new bearings or 5-7 lb.in.
(6 lb.in. desired) with used bearings is required to
rotate the gauge plate assembly.
c. Position gauging arbor J-21691-6 in side bearing
bores of the carrier, install side bearing caps in their
respective positions and torque the bearing cap bolts
to 33
lb.ft. See Figure 4B-13.
d. Position adjustable height block J-21691-3 firmly
against the face of gauge plate J-21691-4. Allow the
movable plunger to bear against
#the machined sur-
face of gauging arbor J-21691-6 and tighten the
plunger set screw. See Figure
4B-14.e. Remove the adjustable height block and use a 1”
to 2” micrometer to measure the distance from the
bottom of the height block to
thetop of the extended
plunger. See Figure
4B- 15.
f. Select the correct pinion depth shim thickness as
follows:
(1) Record the height block dimension as determined
in step
(e).
I4814
/Figure 48.14 Gauging Pinion Depth
HEIGHT BLOCK
MICROMETER
48-15Figure 4B-15 Measuring Adjustable Height Block
(2) The control figure (on face of pinion) is shown in
Figure
4B-16.If the CONTROL FIGURE (underlined) is plus,
convert the figure from millimeters to inches and
subtract from Step (1). If the CONTROL FIGURE
(underlined) is minus, convert the figure from milli-
meters to inches and add to Step (1).
(3) Record the result from Steps (1) and (2).
(4) Subtract from Step (3) the nominal figure 1.468.
(5) The difference between Steps (3) and (4) is thick-
ness of shims required to set the pinion,

48. 181973 OPEL SERVICE MANUAL
Figure 48.26 Checking Torque
to Rotate Gear
in;! surfaces are free of burrs or foreign material.
Tighten bolts to 47 lb.ft.
10. Check lateral runout of installed ring gear. Max-imum permissible runout is
.003”. If runout is
greater than specified, make certain that dirt or burrsare not holding the ring gear in a cocked position on
the case and that the bolts are evenly
torqued.Figure 48-27 Installing Differential Side Bearings
g. Install shim packs with respective side bearing1 I.
In.stall side bearings using installer J-22919 and
drive handle J-8092. Support opposite side of case on
pilot J-2241-1
1 to prevent bearing damage. See Fig-ure
4B-27.12. Determine differential side bearing preload and
backlash as follows:
a. Position differential case assembly less side bear-
ing shims into the side bearing bores of the carrier.
See Figure
4B-28.Figure 48.28 Installing Differential Case Assembly
b. Using two sets of feeler gauges, insert feeler stockof suffcent thickness between each bearing outer
race and the carrier to remove all end play. Make
certain the feeler stock is pushed to the bottom of thebearing bores. See Figure
4B-29.
c. Mount dial indicator J-8001 on carrier so indicator
stem is at right angles to a tooth on the ring gear. SeeFigure
4B-29.d. Adjust feeler gauge thickness from side to side
until ring gear backlash is ,004” to
.OO8” (.005” is
desired).e. With zero end play and correct backlash estab-
lished, remove feeler gauge packs, determine thick-
ness of shims required and add ,002” to each shim
pack to provide side bearing preload.
f. Remove case assembly and both side bearings us-ing J-22588 with adapter leg J-22939 and pilot
J-
2241-l 1.

REAR AXLE48.19FEELER
DIAL INDICATORDIFFERENTIAL
Figure 48.29 Removing Differential Case and End Playusing installer J-22919, driver handle J-8092 and pi-
lot J-2241-11.16. Install torque tube assembly.
17. Install axle shafts.
13. Position case assembly and outer races in the
carrier. Use a soft faced hammer to drive the case
into the carrier until the side bearing outer races
bottom in their bores.Assynbly and Installation of Differential Case
- GT
14. Install side bearing caps in their original location
and torque the bolts to 33
Ib.ft.
1. Lubricate the thrust washers, side and pinion gears
and install the side gears with respective thrust wash-
ers in the differential case.
15. Rotate case assembly several times to seat the
bearings. Check backlash and preload using a torque
wrench on a ring gear attaching bolt. See Figure
4B--68. Torque required to turn case should be 20 to 30
lb.in. for new bearings or 10 to 20 Ibin. for used
bearings. If torque is not correct, it will be necessary
to reshim the side bearings.2. Install the pinion gears and thrust washers be-tween the side gears 180 degrees apart and rotate the
gears as an assembly until the pinion gear bores are
aligned with pinion shaft bores in the case.
3. Install pinion shaft so that the lock pin hole in the
shaft aligns with the lock pin hole in the case.