1973 OPEL GT-R oil

causes the sprags to wedge and prevent rotation in
one direction, and to allow free rotation in the oppo-
site direction.7C. 441973 OPEL SERVICE MANUAL
The clutch is released by exhausting the oil from
behind the piston. The release springs push the pis-
ton to the released position, thereby removing the
force from the plates. See Figure 7C-16.Band
A band is used to hold one planetary member sta-
tionary with relation to the other planetary mem-
bers.
!See Figure 7C-19. The band is connected to the
SPR
7C-16Figure
7C-16 Sprag Cage Assembly
Sprag C(utchA sprag clutch is an overrunning clutch which allows
rotation in one direction only and consists of an inner
race, an outer race and the sprag assembly.
The sprag assembly itself consists of sprags, retainer
rings and a spring. See Figure 7C- 16. The sprags are
mounted at intervals between the two concentric re-
taining rings. The spring is located between the rings
and surrounds the ‘narrow portion of the sprags.
One diagonal dimension of each sprag is greater than
the distance between the inner and outer race, while
the other diagonal is less. See Figure
7C-17. This
\ \I’b+ SPRAG
DISTANCE AFigure
7C-17 Sprag Operational Schematictransmissio; case (stationary anchor) and is ope-
rated by a servo piston. One band is used in the Opel
Three: Speed Automatic Transmission and holds the
reaction sun gear and drum stationary in first and
second gear.
BAND\- D7uM
PRESSURE
STATIONARY
PASSAGE
yPlSfON
1 y””SERVO BODY RELEASE SPRING
7c19
Figure
7C-19 Band Application
COMPONENT OPERATION AND LOCATIONThe power flow and principles of operation of the
Opel Three Speed Automatic Transmission power
train are most easily understood when each unit is
considered separately with a part by part build up of
the unit.
The torque converter is connected to the engine by
means of a flex plate which is bolted directly to the
engine crankshaft and to the converter cover. The
converter cover is welded to the converter pump
member which provides a direct connection of the
engine to the converter. The converter pump hub tits
into the transmission oil pump driving the oil pump
whenever the engine is operating. See Figure
7C-20.The input shaft is splined into the hub of the turbine,
delivering the converter’s output torque to the trans-
mission gear train. See Figure
7C-21.

AUTOMATIC TRANSMISSION7c- 45
Figure 7C-20 Converter. Converter Housing And oil Pump
INPUT SHAFT AND THIRD CLUTCH DRUM
Figure 7C-21 Input Shaft And 3rd Clutch Drum

712.461973 OPEL SERVICE MANUAL___-.. _~--- ..- -_.-. -
THIRD CLUTCH ASSEMBLY7D22
Figure 7C-22 Third Clutch Drum, Piston and Springs, Clutch Plates,
Input Sun Gear. Sprag Race And Retainer Assembly
The stator shaft is an integral part of the transmis-
sion oil pump and supports the stator assembly at the
inner race of the roller clutch assembly.
The input shaft is welded to the third clutch drum.
The sprag outer race is splined to the third clutch
drum and the inner race is splined to the input sun
gear. See Figure
7C-22.The second clutch assembly is supported by the oil
pump hub. The second clutch composition plates are
splined to the outside of the third clutch drum, mak-
ing the third clutch drum the hub for the second
clutch. The ring gear is splined to the second clutch
drum. See Figure
7C-23.The reverse clutch piston assembly is housed on the
back side of the oil pump body. The reverse clutch
steel plates are splined to the transmission case and
the composition plates are splined to the outside of
the second clutch drum. See Figure
7C-24. The re-
verse clutch serves to hold the 2nd clutch drum and
ring gear stationary in reverse range.
The ring gear surrounds the planetary carrier and
the teeth mesh with the front portion of the long
pinions. The reaction sun gear is pressed into the
reaction sun gear drum. See Figure
7C-25. The low
band is wrapped around the reaction sun gear drum
to function as the holding member for the reaction
sun gear.

AUTOMATIC TRANSMISSION7c- 47
SECOND CtUTC7cz3
Figure 7C.23 Second Clutch Drum. Piston, Springs, Clutch Plates, Spacer And Ring Gear
REVERSE CLUTCH ASSEMBLYSECOND CLUTCH
DRUM
SECOND CLUTCH
REVERSE CLUTCH ASSEMBLY
DRUMFigure 7C-24 Oil Pump. Reverse Clutch Piston, Springs, Clutch Plates and Second Clutch Drum

7C- 481973 OPEL SERVICE MANUAL
INPUT SUNRING
GEAR ASSY.GEARPLANETARY
CARRIERASSY.REACTION SUNtow
GEAR 8 DRUMBAND
Figure 7C-25Planetary Gears
The planetary pinion shafts which support the plane-
tary pinions are secured to the planetary carrier by
means of a lock plate at the rear of the planetary
carrier preventing the pinion shafts from rotating or
working loose. The lock plate is secured to the car-
rier by screws.
The planetary carrier is welded to the output shaft,
therefore, the directional movement of the carrier
delivers the transmission’s torque to the output shaft.
The governor hub is splined to, and driven by, the
output shaft. See Figure 7C-26. A governor body is
bolted to the governor hub. The speedometer drive
gear is also driven by the output shaft, and is secured
to the shaft by a retaining clip.
MECHANICAL OPERATIONThe following information describes how engine
torque is transmitted through the Opel Three Speed
automatic transmission for each selected position on
the quadrant. In every case, with the engine running,
torque is transmitted via the flex plate and converter7G25
cover to
tht? pump member of the converter. The
converter is always tilled with oil from the transmis-
sion’s oil pump, and the converter pump member
transmits the torque through oil to the driven mem-
ber of the converter. Power to the transmission is
then transmitted via the input shaft and third clutch
drum. See Figures
7C-48 through 7C-52.
HYDRAULIC CONTROL UNITS AND VALVESPreviously, the mechanical aspects of the transmis-
sion operation have been described, including refer-
ence to various clutches and the low band being
applied. The following describes, in detail, the hy-
draulic system that applies the clutches and band,
and which controls the manually selected and auto-
matic shifts.
A hydraulic pressure system requires a source of
clean hydraulic fluid and a pump to pressurize the
fluid. Opel Three Speed Automatic transmission uses
a gear type pump which draws oil through a screen
located in the sump. See Figure
7C-29. Since the
pump drive gear is keyed to the converter pump hub,
it turns whenever the engine is operating and turns
the driven gear, which causes the oil to be lifted from

AUTOMATIC TRANSMISSION7c- 49Figure 7C-26 Governor Assembly And Speedometer Drive Gearthe sump. The oil is carried past the crescent section
of the pump, beyond which the gear teeth begin to
come together, pressurizing the oil as it is squeezed
from between the gear teeth. The pressurizeh oil is
then delivered through the pump outlet to the hy-
draulic control system.1. Main pressure regulator valve.
2. Modulator valve.
mPRIMING VALVE
If the vehicle has not been operated for a while, the
oil in the pump cavity tends to drain and leak back
to the sump. With the pump cavity filled with air, the
pump cannot develop enough suction to lift the oil
from the sump. For this reason, a priming valve is
located in the pump pressure passage. As the air in
the pump is compressed by the gears, it is forced out
through the bleed orifice in the priming valve and
into the exhausted cavity behind the reverse piston.
This permits the pump to prime and draw oil from
the sump. As soon as the hydraulic pressure reaches
15
PSI: the valve is forced over closing off the bleed
orifice.PRIMING VALVE
In the hydraulic control circuit, there are four major
types of iontrol elements. These categories along
with the specific items are listed below.
A. Pressure regulating valves.
Fieure 7C-7.9 Oil Puvp and Priming Valve

712.501973 OPEL SERVICE MANUAL
3. Detent pressure regulator valve.
4. 1 - 2 Accumulator valve.
5. Governor.
B. Selector valves (manually and hydraulically con-
trolled).
I. Manual valve.
2. Detent valve.
3. 1
- 2 Shift valve.
4. 2
- 3 Shift valve.
5. 3
- 2 Downshift control valve.
6. Manual low and reverse control valve.
7. Boost control valve.
C. Timing Valves.
1. Low speed downshift timing valve.
2. High speed downshift timing valve.
3. Second clutch orifice valve.
D. Accumulators.
1. 1
- 2 Accumulator.
2. Low servo piston.
Main Pressure Regulator ValveOil pressure from the pump is delivered to the “line”
port of the main regulator valve. See Figure
7C-30.The port is connected through a damping orifice, to
the regulator port at the end of the regulator valve.
As the pressure in this port increases, it moves the
valve against the spring force until the second spool
of the. valve just opens to the “line” port. This per-
mits the pump pressure to be by- passed into the
pump suction passage. Therefore, the valve will regu-
late at
a’ fixed minimum pressure as determined by
the spring force, and all excess pump delivery will be
by-passed back into the pump suction passage.
In moving from the “bottomed” to the regulating
position, the valve also opens line pressure to the
converter feed passage. This oil is directed to and
through the
cow&x, through the oil cooler, to the
gear box lubrication system, then back to the sump.
In order to provide the required capacity in the band
and clutches, it is desirable to have a variable line
pressure that will increase with engine torque. This
PRESSURE’REGULATORY7c30Figure 7C-30 Pressure Regulator Valve
is accomplished by introducing a “modulator” pres-
sure on the end of the boost valve. The force of the
boost valve acts against the end of the regulator valve
and increases the line pressure above the base pres-
sure as established by the spring force. By introduc-
ing line pressure to the stepped area between the
spools of the boost valve, an additional pressure in-
crease over and above that described above is ob-
tained.
The regulated line pressure is then fed to:
Manual valve.
Modulator valve
Detent pressure regulator valve
Modulator Valve and Vacuum ModulatorLine pressure is directed to the second port of the
modulator valve. See Figure
7C-31. This pressure
passes between the spools of the valve and into the
modulator port. The modulator port is connected to
the regulating port at the end of the valve through a
damping orifice. As the pressure in the regulating
port incieases, it moves the valve outward against
the spring force of the modulator assembly until the
end spool just closes the line port. If excess pressure
has built up in the regulating port the valve will
continue to move till the second spool just opens to
the exhaust port. In other words, the valve tends to
regulate between the line and exhaust ports.
Even though the modulator spring force may be con-
stant, thereby causing the modulator valve to regu-
late at a fixed pressure, the pressure requirements

7C- 521973 OPEL SERVICE MANUAL
CCUMULATOR
DRIVE:--7633
Figure 7C-33 1
- 2 Accumulator Valve
The ports and spools operate as previously described.
However, for increased engine torque, it is necessary
to increase the accumulator pressure. This is accom-
plished by introducing modulator pressure to the
small end of the 1-2 accumulator valve. As the
modulator pressure increases, it adds to the spring
force and increases the l-2 accumulator pressure.
The 1-2 accumulator pressure is fed to the bottom
(spring loaded side) of the 1-2 accumulator piston.
The Governor is mounted on the output shaft and
contains two interconnected regulating valves See
Figure
7C-34. Its purpose is to supply an oil pressure
5 8I. GOVERNOR SECONDARY VALVE6
SPRING RETAINER
2. GOVERNOR SECONDARY VALVE SPRING
3. GOVERNOR SECONDARY VALVE
4. GOVERNOR PRIMARY VALVE
5. GOVERNOR BODY6. ROLL PINIC~VFigure 7C-34 Governor Assemblythat is a function of output shaft or car speed. Line
pressure is supplied to the governor from the Manual
Valve (to be covered later). The governor operates on
the principle of centrifugal force. That is, as an object
spins off center at changing speeds, its outward force
is a function of the rotating speed.
Line pressure is directed to the outer-most port of the
secondary valve. The secondary spring holds the
valve in an outward position so that the outer spool
of the valve is open to “line”. As the line pressure
builds up between the spools, it exerts a force on the
larger diameter inner spool to start counteracting the
spring. When the hydraulic force is large enough, it
moves the valve inward against the spring force until
the outer spool closes the line port. If the pressure
between the spools still creates a force larger than the
spring force, the valve will continue to move inward
until the excess pressure opens to the exhaust port.
The valve then regulates between the line and ex-
haust port.
A fixed governor pressure in the secondary valve has
now been established with no rotation of the output
shaft. As the governor begins to rotate, the outward
force (due to the weight of the secondary valve) is
added to the force of the spring. Therefore, as the
speed increases, the outward force and in turn the
secondary valve pressure increases.
The secondary valve pressure is directed to the feed
port of the primary valve. With no rotation of the
governor, the pressure acts against the large inner
spool and forces it to open to the exhaust port. Since
there is no spring force on the primary valve, it will
continue to keep the feed port closed and the exhaust
port open. The final governor pressure is then zero.
As the governor begins to rotate, the weight of the
primary valve creates an outward force working
against the oil pressure. The pressure in the primary
valve port now increases as a function of speed. This
continues up to the speed where the outward force
finally holds the primary valve outward, keeping the
feed port open.
In summary, at zero speed, the governor pressure is
zero. As the speed increases, the governor pressure
will increase as dictated by the primary valve until
the speed is great enough to hold the primary valve
all the way out. At speeds above this point, the gover-
nor pressure is established by the secondary valve.
Governor pressure is then directed to:
Modulator Valve.
1 - Two Shift Valve.
2
- Three Shift Valve.
3 High Speed Downshift Timing Valve.