Page 966 of 1226
Automatic Tr;
Vehicles Wil
307-01 -6 Transn
~nsmission/Transaxle -
:h: 4-Speed Automatic
~ission (AW81-40) --
DESCRIPTION AND OPERATION
Item Description
I 1 I I st - 3rd gear clutch 1
1 2 14th gear brake I
1 3 1 Reverse gear clutch I
1 4 )2nd - 4th gear brake I
1 5 1 Reverse gear brake I
1 6 1 3rdl4th gear clutch I
1 7 ITorque converter 1
1 8 1 Transmission input shaft I
1 9 I Fluid pump I - --
[ 10 1 Differential assembly I
~l~put wheel, planetary gearset I
11
1 13 1 Planetary gearset I
Intermediate gear stage
vlIlstgear one-way clutch I
1 15 1 2nd gear one-way clutch I
Torque converter with Torque
Converter Clutch (TCC)
Item Description
I 1 I Torque converter housing and impeller I
1 2 1 Turbine wheel 1
1 4 1 Transmission input shaft I
FlGwith roller-type one-way clutch (
The torque converter hydraulically transmits the
output torque from the engine to the input shaft of
the transmission.
The stator increases the torque up to the clutch
point (approx. 90
% speed difference between the
impeller and the turbine wheel).
In order to increase the efficiency of the automatic
transmission, the torque converter is also equipped
with a hydraulically activated TCC
The TCC is applied with slip to ensure soft
engagement.
i
When the TCC is engaged, the torque is '..
transmitted directly from the crankshaft via the
torque converter housing to the transmission input
shaft.
2006.0 Fiesta 1212006 ~380521 en
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Page 967 of 1226
Automatic Transmission/Transaxle -
Vehicles With: 4-Speed Automatic
Transmission (AW81-40)
DESCRIPTION AND OPERATION
The TCC is engaged depending on the current
driving situation when the selector lever is in
I position "D" and 3rd or 4th gear is engaged. When
4th gear is disabled
(OID Off) the TCC is
engaged in 3rd gear depending on the current
driving situation.
Fluid pump and stator shaft
Item Description It sucks up transmission fluid from the oil pan,
1
2
3
2006.0 Fiesta 1212006 G380521 en
Fluid pump housing
4 builds
up the oil pressure and then supplies it under
high pressure to the main control body.
Inner rotor, fluid pump
Outer rotor, fluid pump The
fluid pump is driven by the crankshaft via the
torque converter housing.
transmission housing.
The fluid pump is a G-rotor oil pump.
The stator shaft is bolted to the fluid pump. It
engages via teeth in the stator of the torque
converter and acts as a support for the latter.
Stator
shaft The
fluid pump housing is bolted to the
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Page 968 of 1226
Automatic Transmission/Transaxle -
Vehicles With: 4-Speed Automatic
Transmission
(AW81-40) 307-01 -8
DESCRIPTION AND OPERATION
Planetary
gearset
Description The following connections exist between the
/ individual components:
small sun gear - short planet gears - long planet
Long planet gear gears- annulus,
3 Small sun gear large sun gear - long planet gears - annulus.
4
5
The output always flows through the annulus.
6
2006.0 Fiesta 1212006 ~380521 en
Short planet gear
Transmission input shaft The different transmission ratios
are selected by
actuating and releasing the individual clutches and
brakes.
shaft via the corresponding clutch either onto the
A Ravigneaux planetary gearset is a two-stage
small sun gear (1st - 3rd gear) or the planet gear gearset with a shared planet gear carrier and one carrier (3rd and 4th gear) or the large sun gear annulus. (reverse gear).
Large sun gear
The drive is transmitted from the transmission input
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Page 969 of 1226
Automatic Transmission/Transaxle -
Vehicles With: 4-Speed Automatic
Transmission
(AW81-40)
DESCRIPTION AND OPERATION
Clutches and brakes
/
Description The clutches are multi-plate clutches.
I 1 I I st - 3rd gear clutch I
1 2 14th gear brake I
1 3 1 Reverse gear clutch I
1 4 12nd - 4th gear brake I
1 6 1 3rdl4th gear clutch I
1 7 1 1st gear one-way clutch I
1 8 12nd gear one-way clutch I
The transmission is equipped with three clutches
and five brakes. The brakes
are three multi-plate brakes and two
one-way sprag clutches.
The clutches serve to transmit the torque from the
transmission input
shaft to certain components of
the planetary
gearset.
The brakes serve to hold certain components of
the planetary
gearset.
In order to achieve a given transmission ratio, it is
necessary for at least one component of the
planetary
gearset to be held while the torque is
transmitted to another component.
These combinations produce the different
transmission ratios for the individual gears.
2006.0 Fiesta 1212006 G380521 en
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Page 970 of 1226
Automatic Transmission/Transaxle -
Vehicles With: $-Speed Automatic
Transmission
(AW81-40)
DESCRIPTION AND OPERATION
Overview of operation
Item Descri~tion
I 1 I I st - 3rd gear clutch I
1 2 12nd gear one-way clutch I
1 3 12nd - 4th gear brake I
1 4 1 1st gear one-way clutch
1 5 1 Reverse gear brake I
1 6 13rd14th gear clutch
Item Description
1 8 1 Output wheel, planetary gearset
I
1 7 1 From the torque converter
1 9 ( Intermediate gear stage I
I
1 10 1 Differential assembly I
I A I Planetary gearset, rear I
11
12
I B I Planetary gearset, front I
4th gear brake
Reverse gear clutch
2006.0 Fiesta 1212006 ~380521 en
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Page 971 of 1226
Automatic Transmission/Transaxle -
Vehicles With: 4-Speed Automatic
Transmission
(AW81-40)
DESCRIPTION AND OPERATION
i '
Intermediate gear stage and differential assembly
1 I
Component Connects
2006.0 Fiesta 1212006 G380521 en
3rdl4th gear clutch
Reverse gear clutch
2nd
- 4th gear brake
4th gear brake
Reverse gear brake
1st gear one-way clutch
2nd gear one-way clutch
* Only in selector lever position 2
** Only in selector lever position 1
Transmission input shaft to planet gear
carrier
Transmission input shaft to large sun gear
Transmission housing to large sun gear
Transmission housing to 2nd gear one-
way clutch
Transmission housing to planet gear
carrier
Transmission housing to planet gear
carrier
4th gear brake to large sun gear
X
X
X**
X X*
X X
XXX X
X
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Page 972 of 1226
Automatic Transmission/Transaxle -
Vehicles With: 4-Speed Automatic
307-01 -1 2 Transmission (AW81-40) 307-01 -1 2 --
DESCRIPTION AND OPERATION
Item Description The output wheel of the planetary gearset drives
I 1 I Output wheel, planetary gearset
2
I I 1
The annulus of the planetary gearset is fixedly Any differences in rotational speed between the
connected to the output
wheel of the planetary two halfshafts are compensated by the differential.
gearset.
the input wheel of the intermediate gear stage.
3
4
Main control body
Output wheel, intermediate gear stage
Item Descri~tion The hydraulic lines and pressures are electronically
The output
wheel of
the intermediate gear stage [<.
drives the spur gear of the differential assembly.
Differential assembly
Input wheel, intermediate gear stage The
differential assembly transmits the torque
via
the halfshafts to the front wheels.
In addition, the manual selector slide in the main
control body provides a hydraulic emergency
running programme which
allows the vehicle to be
Manual selector lever driven in 3rd aear with the selector lever in position
.
1
Shift timing solenoid valve
5
2006.0 Fiesta 1212006 ~380521 en
regulated by a proportional solenoid valve (main
regulating valve) and four shift solenoid valves.
1 6 1 SSA shift solenoid valve
SSB
shift solenoid valve
transmission control unit-fail. -
"D", "2" or "ll'and in reverse gear with the selector
lever in position "R if key components or the
The hydraulic pressure is distributed to the The
manual selector slide is actuated by the driver
individual clutches and brakes in the main control via the selector lever, the selector lever cable, the
body. selector shaft lever and the internal gearshift
mechanism.
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Page 973 of 1226
Automatic Transmission/Transaxle -
Vehicles With: 4-Speed Automatic
307-01 -1 3 Transmission (AW81-40) 307-01 -1 3
DESCRIPTION AND OPERATION
Internal gearshift mechanism
Item Description The movement is then transferred via the selector
1
2
I I I The cone displaces the parking pawl when the
The mechanical parking lock secures the vehicle
selector lever position wPw is against rolling away.
The parking pawl engages in the teeth on the
When the vehicle is stationary it is engaged purely
output wheel of the planetary gearset. mechanically via the selector lever when the
selector lever position "P" is engaged. Accordingly,
the differential is blocked via the
intermediate shaft, and the vehicle is secured and
The movement of the selector lever is transmitted
cannot roll away. via the selector lever cable to the selector shaft Stepped cam
with actuating lever for the
3
4
lever. Selector
shaft
2006.0 Fiesta 1212006 G380521 en
shaft to the stepped cam.
forms part of the stepped cam, and it is used to
actuate the manual selector slide in the main
Actuating rod for the parking pawl with cone
Parking pawl
manual
selector slide
control body.
The actuating rod for the parking pawl with cone
is hooked into the stepped cam.
The actuating lever for
the manual selector slide
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