1973 OPEL GT-R automatic transmission

AUTOMATIC TRANSMISSION7c- 39
TURBINESTATOR
(DRIVEN MEMBER)fREACTION
MEMBER)CON;ERTER
COVERP;MP
(DRIVING MEMBER)
7c.3Figure
7C-3 Torque Converter Assembly
energy of the oil to the turbine. See Figure
7C-1. The
driven member, or turbine is splined to the transmis-
sion input shaft to transmit turbine torque to the
transmission gear train.
When the engine is idling, the converter pump is
being driven slowly. The energy of the oil leaving the
pump is very low, therefore there is very little torque
imparted to the turbine. For this reason, the engine
can idle and the car will have little or no tendancy
to “Creep.”
As the throttle is opened and pump speed increases,
the force of the oil leaving the pump increases and
the resultant torque is absorbed by the turbine.
After the oil has imparted its force to the turbine
member, oil leaving the turbine follows the contour
of the turbine blades so that it leaves the turbine
spinning counterclockwise. Since the turbine mem-
ber has absorbed the energy required to reverse the
direction of the oil, the turbine now has greater forceor torque than is being delivered by the engine, and
the process of torque multiplication has begun.TURBINE
PUMPTURBINE
PUMP7c4Figure
7C-4 Oil Flow Without Stator
If the counterclockwise spinning oil were allowed to
return directly to the converter pump, the oil would
strike the inner section of the pump blades in a direc-
tion that would hinder its rotation, cancelling out
any gains in torque that have been obtained. To pre-
vent this, a stator assembly is added, and is located
between the converter pump and turbine. See Figure7c-5.
The stator redirects the oil returning to the pump
member of the converter and changes its direction of
rotation to that of the pump. Since the direction of
the oil leaving the stator is not opposing the rotationof the pump, the energy or torque of the engine is
added to the oil as it passes through the
the entire cycle repeats. See Figure
7C-6.pump and
The force of the returning oil from the turbine tends
to rotate the stator in a counterclockwise direction,
the stator is mounted on a one-way or roller clutch
which allows it to turn clockwise but not counter-
clockwise. Therefore, at low turbine speeds, the re-
turning oil from the turbine striking the stator blades
in a counterclockwise direction causes the roller
clutch to “lockup,” and prevent the stator from turn-
ing.
As the turbine speed increases, the direction of the
oil leaving the turbine changes and flows against thestator blades in a clockwise direction. Since the sta-tar would now be hindering the smooth flow of re-
turning oil to the pump, the roller clutch releases,
and the stator rotates freely on its shaft. With this
condition, the stator becomes ineffective and no fur-
ther multiplication of engine torque is produced
within the converter. At this point the converter acts

7C- 401973 OPEL SERVICE MANUAL
ENERGIZING SPRINGS
UTER RACE (CAM)
ROLLER CLUTCHSTATOR
LOCKS UPSTATOR
COUNTER CLOCKWISE FORCES ON CAM, LOCKOVERRUNS
ROLLERS TO INNER RACE
CLOCKWISE FORCES ON CAM CAUSESTATOR ASSEMBLYx.5
ROLLERS TO OVERRUN INNER RACE
Figure 7C-5 Roller Clutch And Stator Assembly
as a fluid coupling, since both the converter pump
and turbine are turning at the same speed, or at a 1:l
ratio.
The torque converter and input shaft actually form
a simple transmission in themselves, however, since
the requirements of an automobile transmission are
greater, some means of providing additional torque,
neutral and reverse, are required. For this reason a
gear set is added behind the torque converter.
Planetary Gears
Planetary gears are used in automatic transmissions
as the basic means of multiplying the twisting force
or torque from the engine. They are so named be-
cause of their physical arrangement and are used
because they permit constant mesh operation, cannot
clash, operate in a minimum of space and distribute
the load over several gears. The simplest planetary
gear set consists of a center or sun gear, internal or
ring gear and a planetary gears called planetary pin-
ions. See Figure
7C-9. The sun gear meshes with theplanetary pinions which rotate freely on their shafts
attached to the planetary carrier. The ring gear
sur-rounds the assembly and meshes with the planetary
pinions. Power flow through the planetary gear set
is accomplished by applying power to one member,
holding another member thus making it a reaction
member and obtaining the transmitted power from
the third member, which can result in any of the
following conditions:
1. Increase torque with a proportional decrease in
output speed.
2. Increase speed with a proportional decrease of
output torque.
3. Reverse direction of rotation.
4. Act as a direct connection for direct drive.
The gear set used in the Opel Three Speed Automatic
transmission is known as a Ravigneaux planetary

AUTOMATIC TRANSMISSION7c- 41
Figure
7C-6 Oil Flow With Stator Active
gear set and utilizes two sets of planetary pinions in
one planet carrier, two sun gears and one ring gear.
See Figure
7C-8.The short planetary pinions are in constant mesh
with both the input (front) sun gear and the long
planetary pinions. The long planetary pinions are inconstr$ mesh with the reaction (rear) sun gear, the
short planetary pinions and the ring gear.
In the first gear the reaction (rear) sun gear is held
stationary. The input (front) sun gear rotates in aclockwise direction (when viewed from the front)
turning the short planet pinions counterclockwise
and the long planet pinions clockwise. The long pla-
net pinions turn the ring gear clockwise and walk
around the held reaction (rear) sun gear driving the
planet carrier and output shaft assembly in a clock-
wise direction. See Figure
7C-10.In second gear the reaction (rear) sun gear is again
held statioinry. The ring gear is the input and is
driven in a clockwise direction turning the long pla-
net pinions clockwise which walk around the station-
ary reaction (rear) sun gear, driving the planet

AUTOMATIC TRANSMISSION7c- 43
LONG PINIONINPUT SUNGPLANETARY CARRIERFigure 7C-12 Third Gear
LONG PINION
ORT PINION
INPUT SUN
PLANETARY CARRIER7c.13Figure 7C-13 Reverse
Three Speed automatic transmission has three disc
clutches, a band and a sprag (overrunning) clutch.
Disc Clutch
A disc clutch serves to connect or disconnect a rotat-
ing member with another rotating member or a sta-
tionary member. A clutch of this type can have one
or mgre discs or plates depending on the desired
capacity.
A disc clutch consists of drive plates, driven plates,
a hub and a drum or housing (depending on whether
the rotating member is being clutched to another
rotating member or a stationary member). Themethod of apply in an automatic transmission is a
hydraulic piston.
One set of plates is lined with friction material and
the other plates are steel. Whether the plates are
designated as “drive” or “driven” plates depends on
the power flow through the clutch.
One set of plates is splined to the drum or housing.
With the piston in the released position, the hub with
its plates are free to rotate relative to the drum or
housing. When hydraulic pressure is applied behind
the piston, the piston forces the drive and drivenp!ates together, thus causing the hub to rotate with
the
drur.1 or remain stationary with the housing. See
Figure 7C- 12.
DRUM
FORCE APPLIED
FORCE APPLIEDr
7c-14
Figure
7C-14 Clutch Applied
CLUTCHAPPLY
\
PISTON
CLUTCH
RELEASE-SPRING
r
HUB
CLUTCH DISCS
RELEASED
CLUTCH HUBFigure
7C-15 Clutch Released

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

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