1973 OPEL GT-R seats

6~. 46,1973 OPEL SERVICE MANUAL
ary barrel, it is provided with g transfer system.
When the secondary throttle valve starts to open,
two‘ports (which are normally just above the closed
valve) are uncovered, causing fuel to feed into the
secondary bore just before the secondary nozzle
starts feeding. This provides for an additional enrich-
ment of the air-fuel mixture at the beginning of full
throttle operation. See Figure
6E-7.
nInFlFigure
6E-7 Primary to Secondary Transfer System
Full Thrdttle Enrichment SystemIf the secondary throttle valve is fully opened, the
vacuum in the throttle valve area is reduced so that
the transfer ports (mentioned above) stop feeding.
However, the vacuum increases greatly in the sec-
ondary venturi area. An enrichment tube which pro-
trudes into the primary venturi area, feeds fuel
continuously during full throttle operation. See Fig-
ure
6E-2.
Acceleration SystemWhenever the throttle is closing, the suction stroke
of the diaphragm pump causes fuel to flow from the
float chamber through the inlet ball valve into the
pump chamber. When the throttle valve is opened
the diaphragm is moved inward by the pump con-
necting rod and the pump lever. Fuel is injected into
the primary bore through the injector tube. The
amount of fuel is determined by the pump stroke.
The inlet ball valve in the pump chamber prevents
fuel from flowing back into the float chamber during
the pressure stroke of the pump. The outlet ball valve
prevents air from being drawn into the injector tube
during the suction stroke of the pump. See Figure6E- 8.
Float Bowl VentilationWhile driving, the float bowl is ventilated from insideFigure
6E-8 Acceleration System
the carburetor. That is, the float bowl is connected
through the vent valve with the area under the air
cleaner.
When the engine is idling or off, the ventilation from
inside is cut off and ventilation from the charcoal
canister is cut in. The upper spring now seats the
valve on the upper seat. See Figure
6E-9.
-6E-9
Figure
6E-9 Float Bowl VentilationThe advantage of an inside vent while driving is that
air cleaner restriction does not enrichen the air fuel
mixture. The purpose of the charcoal canister vent
while idling or after shutting-off a hot engine, is to
prevent excess fuel vapors from entering the intakemanifold and outside air. Excess fuel vapors may
cause an idling engine to stall, or may make it dif-
ficult to restart a hot engine.

6E- 561973 OPEL SERVICE MANUAL
valve stop screw. Loosen the stop screw until the
valve is completely closed. Turn the screw in l/4turn from closed position, hold, and tighten lock nut.
This is done to insure that the throttle blade will not
stick closed. See Figure
6E-30.PUMPFigure 6E-30 Adjusting Secondary Throttle Valve Gap
24. Install accelerator pump connecting rod in lower
hole of primary throttle shaft lever and cotter pin in
outboard hole at accelerator pump actuating lever
end. Paying attention to proper arrangement of cot-
ter pin and washers. See Figure
6E-2.25. With throttle plate completely closed, there
should be no clearance between the pump levei and
the pump plunger rod.
26. If a clearance is present, loosen 4 accelerator
Figure
6E-31 Accelerator Pump CoverFigure 6C32 Accelerator Pump Cover
pump cover retaining screws and allow the
dia-’phragm spring to push plunger against lever so that
a zero clearance exists. Then retighten the screws.
See Figures
6E-3 1 and 6E-32.27. Insert accelerator pump discharge nozzle so that
the bent tube end points into suction channel of the
primary barrel.
28. Fill the bowl with fuel.
29. With fuel in bowl, slowly open the throttle and
observe the accelerator pump pressure relief valve
exhaust ports and where it seats into the bowl. See
Figure
6E-33. Fuel should not be bleeding back into
the bowl from the exhaust ports or where the relief
valve seats, but a steady stream of fuel should dis-
charge from the discharge nozzle.
30. With fuel in bowl, rapidly open the throttle atid
observe the exhaust ports of the pressure relief valve.
See Figure
6E-33. Fuel should~exhaust’from the ac-
celerator pump pressure relief valve exhaust ports.
3 1. If the pressure relief valve malfunctions, remove
it and replace with a new one.
32. No float adjustment is possible, so check position
of float arm by comparing with a new float of thesame carburetor type. If float arm is bent, replace
float.

Figure 78-5 1 Position of Third, Fourth, and Reverse
Intermediate Lever on Selector Shaft
1ST. 2ND IlrFigure 78.52 Position of First and Second
Intermediate Lever on Selector Shaft
3. Install spiral pins to secure both intermediate lev-
ers to the selector shaft. Spiral pins should not be
flush with lever surface, but rather should extend up
between
l/16 and 5/64 inches.
Installing Reverse Speed Shifter Intermediate
Lever and Interlock Balls, Springs, and Plugs
1. Engage reverse speed shifter intermediate lever
with third, fourth, and reverse intermediate lever and
also in slot in reverse gear shifter shaft, and install
79-321973 OPEL SERVICE MANUAL
bedding bolt through reverse speed shifter intermedi-
ate lever and into case. Reverse speed shifter inter-
mediate lever end play on bolt should be between
,004 and .012 inches.
2. Insert both interlock balls and then springs, and
drive both interlock plugs into case holes until they
bottom in interlock plug hole seats. Grooves in plugs
will be showing.
Installing Countershaft Gear Unit
1. Coat thrust washers with ball and roller bearing
grease and stick to transmission case. Lugs of thrust
washers must fit into transmission case slots. See
Figure
7B-49.2. Turn transmission case extension housing until
gear unit countershaft bore is completely exposed.
3. Place lock ball into shaft and from the rear of the
transmission insert shaft so that thrust washer is held
in position. Hold opposite thrust washer in position
by using a short drift.
4. Insert countershaft gear unit into transmission
case. Be sure all needle bearings and both needle
bearing washers are in place.
5. Insert gear unit countershaft into gear unit and
drive shaft into transmission case while driving out
Special Tool J-2291 1. Pay attention to lock ball. See
Figure
7B-53.Figure 78-53 Installing Countergear Shaft
Installing Transmission Case Extension Housing
1. Align transmission case extension housing and
gasket and torque (3) bolts with spring washers to 21
lb. ft.

7C- 561973 OPEL SERVICE MANUALMODULATORFigure
7C-42 Low Speed Downshift Timing Valve
During a “coast” condition, the vacuum is high and
the modulator pressure is zero. The spring holds the
timing valve in a bottomed position and the servo
release pressure is exhausted through a restricting
orifice, thus delaying the apply of the servo.
During a “power on” 3-2 downshift at lower car
speeds, the servo must be applied rapidly. During
such a shift, the vacuum will be somewhat lower and
the resulting modulator pressure will force the valve
over against the spring. This provides an unrestricted
passage for servo release, thus permitting rapid apply
of the servo.
High Speed Downshift Timing Valve
When a 3-2 downshift is “forced” at high car speeds,
the application of the band must be delayed. Servo
apply pressure is directed through the high speed
downshift timing valve. See Figure
7C-43.The timing valve is held in a bottomed position by
the spring at lower car speeds. This permits an unre-
stricted
flow for servo apply. At higher car speeds,
approximately 25 to 35 MPH, (depending on axle
ratio and engine), governor pressure forces the valve
over against the spring. This closes off the direct feed
to servo apply and the feed is controlled by a fixed
orifice.While it may outwardly appear that the functions of
the two downshift timing valves are contradictory,
whether or not the application of the band is delayed
during a 3-2 downshift is a combined function of car
speed and throttle position.
--Figure
7C-43 High Speed Downshift Timing Valve
Second Clutch Orifice Valve
For reasons of shift timing, it is necessary to have
different restricting orifice sizes for the feed and ex-
haust of the second clutch. This is accomplished by
introducing a “one way” ball check in the second
clutch circuit. See Figure
7C-44.2ND CLUTCH
I?C-44
Figure
7C-44 Second Clutch Orifice Valve
When the second clutch is being applied, the apply
pressure seats the ball and the feed is directed
through a single orifice. During the release of the
clutch, the ball is unseated and the clutch can ex-
haust at a faster rate through the two orifices.

f. Operation of Controls in Low Range First GeaReverse Clutch ReleasedThird Clutch Applied
Second Clutch Released
Low Band Applied
Sprag Locked
When the
selector lever is moved to the low position on the quadrant. the manualvalve is positioned to allow drive oil, intermediate oil and low oil to pass
through the valve. Low oil is directed to the
1 2 shift valve train which acts with the I 2 shift valve spring against governor oil pressure to close off drive
oil from passing into the second clutch passage. At the
same time, low oil is directed to the Reverse and Low control valve and acts against the spring to
allow detent regulated oil at the Reverse and Law control
valve to flow to the 2 3 shift valve, which is bottomed in its bore by intermediate oil pressxeand the valve spring. The detent oil
pazses through the 2 3 shift vahre and into the third clutch oil passages to apply the third clutch and to close off
modulator oil pressure from the 3-2 control valve to the 2 3 shift control valve. Third control oil isalSo directed to the Reverse and Law control
valve.which is held open against its spring by low oil pressure. and closes off the
source of rupply to the servo release pasege. to allow the servo to apply the low
band. Intermediate oil seats the check ball at the Reverse
passage at the presue regulator boost valve cavity and continues to the pressure regulator valve
to increase oil pressure in the circuit.
iThe third clutch in on, the band is on. The transmi&n is in Low Range First Gear

AUTOMATIC TRANSMISSION 7C-109
Figure 7C-149
21. Using a drift on tap, press out oil pump bushing
with arbor press. Use rag or cloth to protect oil pumpface.22. Install new oil pump hub bushing with arbor
press using tool J-23130-1. See Figure
7C-149. Clean
pump body, including all holes and pockets
thoroughly. With oil pump shaft hole “A” facing
downward, scribe an aligning mark on oil pump
shaft inner diameter at the center of the oil groove
to the right of hole “A”. Scribe mark on outer edge
of bushing through the centers of the small and large
drilled holes “B”. Place bushing into oil pump shaft
with small hole up, and align scribe marks on bush-
ing with those made in oil pump shaft. Use arbor
press to drive bushing into oil pump shaft until
seated in the bore. Care must be taken so that bush-
ing is pressed in straight, using the scribe marks as
a guide until firmly seated.
23. Inspect and thoroughly clean the pressure regula-
tor and priming valve assemblies. Immerse all valves
in transmission fluid before installing in bores.
24. Install pressure regulator valve in oil pump body
bore. See Figure
7C-150.25. Install pressure regulator valve, two spring seats,
spring, boost valve and sleeve in oil pump body bore.
26. Depress pressure regulator boost valve sleeve un-
til backend lines up with pin hole and insert pin to
XWP$.27. Install priming valve assembly from front face of
pump. Priming valve retainer should be pressed in
flush with surface of oil pump body. See Figure 7C-
151.28. Inspect oil pump hub oil seal rings. Replace if
damaged or side wear is noted. See Figure
7C-152.29. Inspect reverse clutch piston for damage, Re-
place if necessary.
Figure
7C-150

AUTOMATIC TRANSMISSION 7C-113
12. Inspect the piston return springs. Evidence of
extreme heat or burning in the area of the clutch may
have caused the springs to take a heat set and would
justify replacement of the springs.
Figure 7C-16313. Inspect second clutch hub bushing for scoring or
wear.14. If necessary, remove second clutch hub bushing
using remover and installer J-23130-6 with driver
handle J-8092. See Figure 7C-164.
P-J-6092
SECOND CLUTCH
DRUM
iJ:23130-6Figure
7C-16415. Clean in solvent to remove any foreign matter.
Install new second clutch hub bushing using tool
J-23 130-6 and driver handle J-8092. Bushing must be
driven in until tool bottoms on bench. See Figure 7C-
164.16. To install second clutch piston into second clutch
drum, use installer tool J-23080 so as not to damage
lip seal. See Figure 7C-165. Use liberal amount of
transmission fluid for ease of installation and to pre-
vent seal damage.
SECOND CLUTCHDRUM
J-23,060Figure
7C-16517. Remove second clutch piston and seal installer
J-23080.18. Install 22 springs and retaining seat on second
clutch piston.
19. Using spring compressor tool J-2590-12 with
adapter J-21420-1 on retaining seat, compress sec-
ond clutch piston return springs. Care should be
taken so that retainer does not catch in snap ring
groove and damage retainer.
20. Install snap ring with snap ring pliers such as
J-
8059.21. Install bronze thrust washer so that the tang seats
in the slot of the second clutch hub. Secure with
petroleum jelly (unmedicated).
22. Inspect condition of composition and steel plates.
Do not diagnose a composition drive plate by co/or.
A. Dry composition plates with compressed air and
inspect the composition surface for:
1. Pitting and flaking
2. Wear
3. Glazing

HEATER SYSTEM - GT9A- 5
MAJOR REPAIR
REMOVAL AND INSTALLATION INSTRUMENT
PANEL FRESH AIR OUTLET
Removal
1. Remove instrument panel cover assembly. Refer
to Group 1.
2. Snap grille out of outlet.
3. Remove knob from lever and remove outlet.
Installation
1. Install outlet and knob onto lever.
2. Snap grille into outlet.
3.
Install instrument panel cover assembly. Refer to
Group 1.
REMOVAL AND INSTALLATION KICK PANEL
FRESH AIR OUTLET
Removal
Using a screwdriver, carefully pry out outlet.
Installation
Install outlet.
REMOVAL AND INSTALLATION BLOWER
SWITCH
Removal
i. Remove instrument panel assembly. Refer to
Group 1.
2. Unscrew switch assembly from panel.
Installation
1. Screw switch assembly to instrument panel.
2. Install instrument panel assembly. Refer to Group
1.
REMOVAL AND INSTALLATION HEATER
Ramova!
1. Remove lower radiator hose, drain, and collect
coolant. 2. Detach coolant feed (A) and return (B) hoses, in
engine compartment from heater core. See Figure
9A-5.
Figure 9A-5 Heater Hose Connections
3. In engine compartment remove hood lock control
cable retaining clip and cable from lock bar. See Figure
9A-6.
Figure 9A-6 Hood Release Control Cable
4. Remove console shift cover between seats using
the following instructions:
a. Remove ash tray and remove two screws under it.