Page 2001 of 2585

SPEED SENSOR - INPUT
DESCRIPTION
The Input Speed Sensor is a two-wire magnetic
pickup device that generates AC signals as rotation
occurs. It is threaded into the transaxle case (Fig.
281), sealed with an o-ring (Fig. 282), and is consid-
ered a primary input to the Powertrain/Transmission
Control Module.
OPERATION
The Input Speed Sensor provides information on
how fast the input shaft is rotating. As the teeth of
the input clutch hub pass by the sensor coil (Fig.
283), an AC voltage is generated and sent to the
PCM/TCM. The PCM/TCM interprets this informa-
tion as input shaft rpm.
The PCM/TCM compares the input speed signal
with output speed signal to determine the following: ² Transmission gear ratio
² Speed ratio error detection
² CVI calculation
The PCM/TCM also compares the input speed sig-
nal and the engine speed signal to determine the fol-
lowing: ² Torque converter clutch slippage
² Torque converter element speed ratio
Fig. 281 Input Speed Sensor Location
1 - INPUT SPEED SENSOR
Fig. 282 O-Ring Location
1 - INPUT SPEED SENSOR
2 - O-RING
Fig. 283 Sensor Relation to Input Clutch Hub
1 - INPUT SPEED SENSOR
2 - TRANSAXLE CASE
3 - INPUT CLUTCH HUB
21s - 140 40TE AUTOMATIC TRANSAXLERS
Page 2002 of 2585
REMOVAL
(1) Disconnect battery negative cable.
(2) Disconnect input speed sensor connector (Fig.
284).
(3) Unscrew and remove input speed sensor (Fig.
285). (4) Inspect speed sensor o-ring (Fig. 286) and
replace if necessary.
INSTALLATION
(1) Verify o-ring is installed into position (Fig.
286). (2) Install and tighten input speed sensor to 27
N´m (20 ft. lbs.) (Fig. 285). (3) Connect speed sensor connector (Fig. 284).
(4) Connect battery negative cable.
Fig. 284 Transmission Connectors
1 - SOLENOID PACK CONNECTOR
2 - INPUT SPEED SENSOR CONNECTOR
3 - OUTPUT SPEED SENSOR CONNECTOR
4 - TRANSMISSION RANGE SENSOR CONNECTOR
Fig. 285 Input (Turbine) Speed Sensor
1 - INPUT SPEED SENSOR
Fig. 286 O-ring Location
1 - INPUT SPEED SENSOR
2 - O-RING
RS 40TE AUTOMATIC TRANSAXLE21s - 141
SPEED SENSOR - INPUT (Continued)
Page 2003 of 2585

SPEED SENSOR - OUTPUT
DESCRIPTION
The Output Speed Sensor is a two-wire magnetic
pickup device that generates an AC signal as rotation
occurs. It is threaded into the transaxle case (Fig.
287), sealed with an o-ring (Fig. 288), and is consid-
ered a primary input to the Powetrain/Transmission
Control Module.
OPERATION
The Output Speed Sensor provides information on
how fast the output shaft is rotating. As the rear
planetary carrier park pawl lugs pass by the sensor
coil (Fig. 289), an AC voltage is generated and sent to
the PCM/TCM. The PCM/TCM interprets this infor-
mation as output shaft rpm.
The PCM/TCM compares the input and output
speed signals to determine the following: ² Transmission gear ratio
² Speed ratio error detection
² CVI calculation
VEHICLE SPEED SIGNAL
The vehicle speed signal is taken from the Output
Speed Sensor. The PCM converts this signal into a
pulse per mile signal and sends the vehicle speed
message across the communication bus to the BCM.
The BCM sends this signal to the Instrument Cluster
to display vehicle speed to the driver. The vehicle
speed signal pulse is roughly 8000 pulses per mile.
Fig. 287 Output Speed Sensor
1 - OUTPUT SPEED SENSOR
Fig. 288 O-Ring Location
1 - OUTPUT SPEED SENSOR
2 - O-RING
Fig. 289 Sensor Relation to Planet Carrier Park Pawl
1 - OUTPUT SPEED SENSOR
2 - REAR PLANET CARRIER/OUTPUT SHAFT ASSEMBLY
3 - TRANSAXLE CASE
21s - 142 40TE AUTOMATIC TRANSAXLERS
Page 2004 of 2585
REMOVAL
(1) Disconnect battery negative cable.
(2) Raise vehicle on hoist.
(3) Disconnect output speed sensor connector (Fig.
290).
(4) Unscrew and remove output speed sensor (Fig.
291). (5) Inspect speed sensor o-ring (Fig. 292) and
replace if necessary.
INSTALLATION
(1) Verify o-ring is installed into position (Fig.
292). (2) Install and tighten input speed sensor to 27
N´m (20 ft. lbs.). (3) Connect speed sensor connector (Fig. 290).
(4) Connect battery negative cable.
Fig. 290 Transmission Connectors
1 - SOLENOID PACK CONNECTOR
2 - INPUT SPEED SENSOR CONNECTOR
3 - OUTPUT SPEED SENSOR CONNECTOR
4 - TRANSMISSION RANGE SENSOR CONNECTOR
Fig. 291 Output Speed Sensor
1 - OUTPUT SPEED SENSOR
Fig. 292 O-ring Location
1 - OUTPUT SPEED SENSOR
2 - O-RING
RS 40TE AUTOMATIC TRANSAXLE21s - 143
SPEED SENSOR - OUTPUT (Continued)
Page 2005 of 2585
TORQUE CONVERTER
DESCRIPTION
The torque converter (Fig. 293) is a hydraulic
device that couples the engine crankshaft to the
transmission. The torque converter consists of an
outer shell with an internal turbine, a stator, an
overrunning clutch, an impeller and an electronically
applied converter clutch. The converter clutch pro-
vides reduced engine speed and greater fuel economy
when engaged. Clutch engagement also provides
reduced transmission fluid temperatures. The con-
verter clutch engages in third gear. The torque con-
verter hub drives the transmission oil (fluid) pump. The torque converter is a sealed, welded unit that
is not repairable and is serviced as an assembly.
Fig. 293 Torque Converter Assembly
1 - TURBINE
2 - IMPELLER
3 - HUB
4-STATOR
5 - CONVERTER CLUTCH DISC
6 - DRIVE PLATE
21s - 144 40TE AUTOMATIC TRANSAXLERS
Page 2006 of 2585
IMPELLER
The impeller (Fig. 294) is an integral part of the
converter housing. The impeller consists of curved
blades placed radially along the inside of the housing
on the transmission side of the converter. As the con-
verter housing is rotated by the engine, so is the
impeller, because they are one and the same and are
the driving member of the system.
Fig. 294 Impeller
1 - ENGINE FLEXPLATE 4 - ENGINE ROTATION
2 - OIL FLOW FROM IMPELLER SECTION INTO TURBINE
SECTION 5 - ENGINE ROTATION
3 - IMPELLER VANES AND COVER ARE INTEGRAL
RS 40TE AUTOMATIC TRANSAXLE21s - 145
TORQUE CONVERTER (Continued)
Page 2007 of 2585
TURBINE
The turbine (Fig. 295) is the output, or driven,
member of the converter. The turbine is mounted
within the housing opposite the impeller, but is not
attached to the housing. The input shaft is inserted
through the center of the impeller and splined into
the turbine. The design of the turbine is similar to
the impeller, except the blades of the turbine are
curved in the opposite direction.
Fig. 295 Turbine
1 - TURBINE VANE
2 - ENGINE ROTATION
3 - INPUT SHAFT 4 - PORTION OF TORQUE CONVERTER COVER
5 - ENGINE ROTATION
6 - OIL FLOW WITHIN TURBINE SECTION
21s - 146 40TE AUTOMATIC TRANSAXLERS
TORQUE CONVERTER (Continued)
Page 2008 of 2585

STATOR
The stator assembly (Fig. 296) is mounted on a sta-
tionary shaft which is an integral part of the oil
pump. The stator is located between the impeller and
turbine within the torque converter case (Fig. 297).
The stator contains an over-running clutch, which
allows the stator to rotate only in a clockwise direc-
tion. When the stator is locked against the over-run-
ning clutch, the torque multiplication feature of the
torque converter is operational.
TORQUE CONVERTER CLUTCH (TCC)
The TCC (Fig. 298) was installed to improve the
efficiency of the torque converter that is lost to the
slippage of the fluid coupling. Although the fluid cou-
pling provides smooth, shock±free power transfer, it
is natural for all fluid couplings to slip. If the impel-
ler and turbine were mechanically locked together, a
zero slippage condition could be obtained. A hydraulic
piston was added to the turbine, and a friction mate-
rial was added to the inside of the front cover to pro-
vide this mechanical lock-up.
Fig. 296 Stator Components
1 - CAM (OUTER RACE)
2 - ROLLER
3 - SPRING
4 - INNER RACE
Fig. 297 Stator Location
1-STATOR
2 - IMPELLER
3 - FLUID FLOW
4 - TURBINE
Fig. 298 Torque Converter Clutch (TCC)
1 - IMPELLER FRONT COVER
2 - THRUST WASHER ASSEMBLY
3 - IMPELLER
4-STATOR
5 - TURBINE
6 - PISTON
7 - FRICTION DISC
RS 40TE AUTOMATIC TRANSAXLE21s - 147
TORQUE CONVERTER (Continued)