1973 OPEL GT-R service

78. 161973 OPEL SERVICE MANUAL
POWER FLOW
- 3rd SPEED
MAIN DRIVE GEAR (INPUT)
COUNTERSHAFT GEAR UNIT 3rd SPEED GEAR
3rd SPEED GEAR
GEAR SHIFTER SLEEVE
GEAR SHIFTER SLEEVE CARRIERCOUNTERSHAFT GEAR UNIT GEAR DRIVE
3rd SPEED GEAR
GEAR SHIFTER SLEEVE
GEAR SHIFTER SLEEVE CARRIER
MAIN SHAFT (OUTPUT)
78-4
Figure 78.4
Third Speed
After synchronizing the speeds of the mainshaft and
the 3rd speed gear, the gear shifter sleeve shifts to the
rear of the transmission and locks the 3rd speed gear
to the mainshaft through the gear shifter sleeve car-
rier. This gear shifter sleeve carrier is internally
splined to the gear shifter sleeve and is externally
splined to the mainshaft. Both the 1st speed gear and
the 2nd speed gear are idling. The reverse idler gear
is
not engaged with any gear and, therefore, it is
idle.
With a 3rd speed gear ratio of
1.366:1, the main drive
gear (input) must turn 1.366 revolutions for every
one revolution of the mainshaft (output).

78.181973 OPEL SERVICE MANUAL
POWER FLOW
- REVERSE SPEED
MAIN DRIVE GEAR (INPUT)COUNTERSHAFT GEAR UNIT DRIVE GEAR
COUNTERSHAFT GEAR UNIT REVERSE SPEED GEARREVERSE IDLER GEAR
REVERSE IDLER GEAR
Is+ AND 2nd GEAR SLIDING GEAR
Is+ AND 2nd GEAR SLIDING GEAR,s+ AND 2nd SPEED SLIDING GEAR GUIDE
1st AND 2nd SPEED SLIDING GEAR GUIDE UNITMAINSHAFT (OUTPUT)
Figure 76.6
Reverse SpeedThrough the engagement of the reverse idler gear
with the 1st and 2nd gear sliding gear (mainshaft)
and the countershaft gear unit reverse speed gear, the
drive is bridged between the countershaft gear unit
and the mainshaft through the guide unit. The direc-
tion of the mainshaft is reversed. The guide unit is
located between the 1st and 2nd gear sliding gear and
the mainshaft. The guide unit is internally splined to
the 1st and 2nd gear sliding gear, and it is externally
splined to the mainshaft. The 3rd speed gear, 2nd
speed gear, and the 1st speed gear are all idling. With
a reverse speed gear ratio of -3.3 17: 1, the main drive
gear (input) must turn 3.317 revolutions for every
one revolution of the mainshaft (output). The “-
’sign indicates that the direction of rotation of the
mainshaft is opposite that of the main drive gear.UNIT756

76.201973 OPEL SERVICE MANUAL
GEARSHIF
INTERMEDIATE SHAFT,
.SHIFT
FINGER1SELECTOR LEVER
JT “B’
78-7Figure’7B.7 Reverse Gearshift Blocker Adjustment
Figure
78-B3. Unhook tension spring of gearshift lever and, after
removal of retaining washer, push pivot pin out of
intermediate shift lever. See Figure
7B-10.1. Prior to installation, grease support and spherical
end of shift finger with protective grease.
2. Replace lever, pivot pin, retaining washer, and
tension spring. Reposition protective cap and bel-
lows and button cap from below. Replace console.
3. In
Figuie 7B-11, distance A - 8.07”.Figure 7B-10
7&l 1Figure 78.1 1
4. After installation, check as to whether pull ring
can be lifted up approximately
.04 to .08”, whereby
the stop sleeve must still rest against intermediate
shift lever. Otherwise, loosen threaded pin forBowden control wire attachment. See Figure 7B- 12.
Adjust distance B
- free travel - by lifting up pull
ring, and retighten threaded pin. See Figure 7B- 13.
REPLACING BOWDEN CONTROL WIRE IN
GEARSHIFT LEVER
1. Remove gearshift lever.

78.221973 OPEL SERVICE MANUAL
3. Install new bellows. Adhere to distance A
- 8.07”.
See Figure 7B-I 1.
4. Heat up new gearshift lever knob in boiling water
to 176 degrees F. and push it onto gearshift lever
tube. Adhere to distance A .3”, see Figure
7B-15.The gearshift lever tube end is provided with trans-
verse grooves for which reason the old button cannot
be reused. Install gearshift lever.
REPLACING RUBBER DAMPENING PARTS IN
GEARSHIFT LEVER1. Remove gearshift lever.
2. Knock off gearshift lever button and loosen
threaded pin for Bowden control wire attachment.
3. Remove lower snap ring from gearshift lever tube
and pull tube off shift finger.
4. Take off and replace rubber dampening parts.
5. After installation of tube, tighten Bowden control
wire with threaded pin. Prior to tightening, pull ring
must rest on gearshift lever tube and clamping block
on pull ring. See Figure
7B-15.6. Heat up new gearshift lever knob in boiling water
to 176 degrees F. and push it onto gearshift lever
tube. Adhere to distance A
- .3”, see Figure 7B-15.The gearshift lever tube end is provided with trans-
verse grooves for which reason the old button cannot
be reused.
7. Install gearshift lever.
MAJOR REPAIR
TRANSMISSION REMOVAL1. Remove air cleaner. Remove throttle rod from
carburetor and rear support and disconnect battery.
2. Remove screws from fan shroud.
3. Remove gearshift lever (refer to paragraph on ser-
vicing gearshift lever).
4. Support car with frame or wheel stands in the
front or frame stands in the rear.
5. Loosen front exhaust pipe to manifold flange.
6. Remove clutch cable from fork by pushing fork to
disengage the clutch and unsnap cable from slot.
7. Disconnect both wires from backup lamp switch.8. Disconnect speedometer cable from transmission
case extension housing.
9. Unhook parking brake cable return spring and
remove cable adjusting nut, equalizer, and spacer.
See Figure
7B-16.PARKING BRAKE CABLE
PARKING BRAKE
Figure 78-16 Parking Brake Equalizer and Return
Spring
9. Disconnect drive shaft at central joint and remove
as follows: See Figure
7B-16.a. Disconnect parking brake cable equalizer from
rod.b. Mark the mating parts of U-Joint and the drive
pinion extension shaft flange.
c. Loosen bolt locks and remove bolts or nuts.
d. Work propeller shaft slightly forward, lower rear
end of shaft and slide assembly rearward. Remove
thrust spring.
e. Install a plug in the rear of the transmission to
prevent loss of lubricant.
10. Remove rear engine mount bolts and lower trans-
mission as far as possible.
11. Remove transmission case to clutch housing at-
taching bolts and remove transmission.
INSTALLATION OF TRANSMISSION WITH
ENGINE IN CAR1. Make certain main drive gear splines are clean and
dry. Also, make certain the transmission is in Neu-
tral so that the main drive gear splines may be in-
dexed when making the installation.
2. Install transmission and support weight while in-
stalling transmission case to clutch housing bolts.
3. Install rear engine mount.
4. Install propeller shaft, align, and tighten U-Joint
to pinion flange U-Bolt nuts and torque to 11 lb. ft.

78.241973 OPEL SERVICE MANUAL
Removing Shifter Shaft
1. Remove cotter pins that secure each end of shifter
shaft. See Figure
7B-20.7&20
Figure 78.20 Cotter Pin Locations on Shifter Shaft
2. Remove shifter shaft with washer and spring
washer at each end.
Removing Selector Lever
1. With punch, drive out pin securing selector lever
to transmission case extension bolt. See Figure 7B-
21.
Figure
78-21 Pin and Bracket Securing Selector
Lever to Intermediate Shaft and Rear Bearing
Retainer2. Remove the two (2) bolts and spring washers from
the transmission case extension housing which se-
cure selector lever bracket. See Figure 7B-2 1.
3. Remove selector lever and bracket. Selector lever
will just slip off selector ring.
4. Remove lock nut and selector ring.
5. Remove transmission case extension bolt. See Fig-
ure 7B-21.Removing Transmission Case Cover
1. Remove ten (10) transmission case cover bolts,
cover, and gasket.
2. Invert transmission to drain oil.
Removing Countergear
1. Remove remaining three transmission case exten-
sion housing to case attaching bolts and spring wash-
ers.2. Turn transmission case extension housing until
gear unit countershaft is exposed. See Figure 7B-22.
Figure
78-22 Position of Rear Bearing So
Countergear Can Be Removed
3. From the front of the transmission, using Special
Tool J-2291 1, drive out shaft. Ensure that lock ball
is not lost. See Figure 7B-23.
Figure
78-23 Removing Countergear Shaft

78.261973 OPEL SERVICE MANUAL
4. Remove both first and second speed shifter yoke
and shifter shaft cam.
Removing Main Drive Gear and Mainshaft
Assembly
1. From front of transmission, pull main drive gear
and needle bearing out of transmission. (May be
necessary to rock main drive gear.)
2. From rear of transmission, pull mainshaft assem-
bly and transmission case extension housing out of
transmission. Gear shifter sleeve will be pulled off
gear shifter sleeve carrier by the third and fourth
speed shifter yoke. Remove sleeve from yoke and
keep sleeve with mainshaft assembly. (Make sure
third and fourth speed shoes are not lost.)
Removing Third and Fourth Gear Shifter Shaft.
1. With main shaft assembly out of transmission
case, drive third and fourth gear shifter shaft out
through hole in front of case with brass drift from
rear of transmission through mainshaft assembly
hole in case.
2. Remove third and fourth speed yoke.
Removing Reverse Gear Shifter Shaft and Reverse
Idler Gear
1. Using a brass drift and from the front of the trans-
mission, drive out reverse gear shifter shaft and plug.
See Figure
7B-28. The reverse speed shifter yoke will
remain in transmission case.
Figure 78.28 Removing Reverse Shifter Shaft
2. With Special Tool J-22923 push reverse idler gear
shaft from front toward the rear. Ensure that lock
ball is not lost. See Figure
7B-29.Figure 78.29 Removing Reverse Idler Gear Shaft
3. Take shaft, reverse idler gear and reverse speed
shifter yoke out of transmission case.
Disassembling Mainshaft Assembly
1. Remove mainshaft bearing snap ring from trans-
mission case extension housing groove and remove
mainshaft assembly from housing. See Figure
7B-30.Figure 78-30 Removing Snap Ring From Rear Bearing
Retainer2. Remove loose parts such as mainshaft needle bear-
ing, mainshaft front ring, synchronizer cover, gear
shifter sleeve, shoes, and front synchronizer spring.
The gear shifter sleeve carrier and the first and sec-
ond speed sliding gear guide unit and their respective
gear shifter sleeve and first and second gear sliding
gear are selected assemblies and should be kept
together as originally assembled. See Figure 7B- 31.

iB- 281973 OPEL SERVICE MANUAL
1 ST SPEED
GINEEDLE BEARING-/CLUTCH
SLEEc?iE,-.
SNAP RING_.. ..~~ ~-KEY SPRING,a-37Figure 70-37Figure 7B-39 Pressing Off Small Clutch Hub
7. With Special Tool J-21684, Press Plate, located
below third speed gear, press out gear shifter sleeve
carrier. See Figure
7B-38.2. Install third speed synchronizer cover onto third
speed gear cone.
J-21604
\
2ND SPEED
GE,ARFigure 78.38 Pressing Off Large Clutch Hub and
Needle Bearing Inner Sleeve8. With Special Tool J-21684, Press Plate, located
below second speed gear, press out gear shifter sleevecarrier. See Figure
7B-39.
TRANSMISSION REASSEMBLY
A. Assembling Mainshaft1. From front of the mainshaft install third speedf;cz&mto mainshaft. Gear must turn freely on main-3. Install rear synchronizer spring into rear side of
gear shifter sleeve carrier so that hooked spring end
rests in one of the slots.
4. Using Press Plate J-21684, press gear shifter sleeve
carrier onto mainshaft so that original tooth contact
is obtained. The rear side of gear shifter sleeve carrier
with installed spring should be toward third speed
gear. This rear side of carrier is recessed more than
front side to allow carrier to be pressed almost flush
with synchronizer cover. See Figure
7B-40.3rd
8 4th
Figure 78.40 Securing Third and Fourth Speed Clutch
Hub on Mainshaft With Snap Ring

78.301973 OPEL SERVICE MANUAL
SHOULDER OR
SHIFTE
.44Figure 78-46 Installing Reverse Shifter Fork
Figure 78.44 Mainshaft Assembly Secured Into Rear
Bearing Retainer by Snap Ring
16. Place front synchronizer spring in the gear shifter
sleeve carrier. Install (3) third and fourth speed shoes
(short design) and gear shifter sleeve over gear shifter
sleeve carrier along with synchronizer cover. Arrows
on shoes point toward rear of mainshaft. Gear shifter
sleeve yoke groove should be toward front.
17. With sealer, install new gasket onto transmission
case extension housing.
Installing Reverse Idler Gear and Reverse Gear
Shifter Shaft1. Inspect shafts carefully for burrs, and remove with
emery cloth. Burrs on shifter shaft will prevent easy
installation of shifter yoke. Lightly oil with transmis-
sion oil prior to installation. Place lock ball into
reverse idler gear shaft and push shaft through hole
in rear of case and on through reverse idler gear
which should have groove end toward front. See Fig-
ure
7B-46.Continue to drive reverse idler gear shaft forward
with plastic hammer until rear end of shaft is flush
with rear case face.
2. Position reverse speed shifter yoke in groove of
reverse idler gear and install reverse gear shifter shaft
from rear of case with notches up, pushing it through
reverse speed shifter yoke. See Figure
7B-47.3. Install spiral pin to secure yoke to shifter shaft and
drive plug into hole in rear of case.Figure 78.47 Third and Fourth Speed Shifter Shaft
Installed
Installing Mainshaft Assembly and Main Drive
Gear1. Slide mainshaft assembly into transmission case
from rear.
2. From the’front, slide mainshaft front ring and the
mainshaft needle bearing onto the mainshaft. See
Figure
7B-48.3. Install main drive gear through front of transmis-
sion case until main drive (standard part) snap ring
is flush with case.
Installing Third and Fourth Gear Shifter Shaft1. Position third and fourth speed yoke onto gear
shifter sleeve. See Figure
7B-47.2. Insert third and fourth gear shifter shaft through
hole in front of case with notches down, pushing it
through third and fourth speed yoke. Third and