Chrysler 1997 Stratus Convertible LHD, Service Manual, Page: 971 / 1196

SPECIAL ADDITIVES
Chrysler Corporation does not recommend the
addition of any fluids to the transaxle, other than the
fluid listed above. An exception to this policy is the
use of special dyes to aid in detecting fluid leaks. The
use of transmission sealers should be avoided, since
they may adversely affect seals.
DESCRIPTION AND OPERATION
CLUTCH AND GEAR
The transaxle consists of:
•
Three multiple disc input clutches
•
Two multiple disc grounded clutches
•
Four hydraulic accumulators
•
Two planetary gear sets
This provides four forward ratios and a reverse
ratio. The clutch-apply pistons were designed with
centrifugally balanced oil cavities so that quick
response and good control can be achieved at any
speed. A push/pull piston is incorporated for two of
the three input clutches.
CAUTION: Some clutch packs appear similar, but
they are not the same. Do not interchange clutch
components, as they might fail.
HYDRAULICS
The hydraulics of the transaxle provide:
•
Manual shift lever select function
•
Main line pressure regulation
•
Torque converter and cooler flow control
Oil flow to the friction elements is controlled
directly by four solenoid valves. The hydraulics also
include a unique logic- controlled solenoid torque con-
verter clutch control valve. This valve locks out the
1st gear reaction element with the application of 2nd,
direct, or overdrive gear elements. It also redirects
the 1st gear solenoid output so that it can control
torque converter clutch operation. To regain access to
1st gear, a sequence of commands must be used to
move the solenoid switch valve. This precludes any
application of the 1st gear reaction element with
other elements applied. It also allows one solenoid to
control two friction elements.
Small, high-rate accumulators are provided in each
controlled friction element circuit. These serve to
absorb the pressure responses, and allow the controls
to read and respond to changes that are occurring.
SOLENOIDS
The solenoid valves perform most control functions,
these valves must be extremely durable and tolerant
of dirt. For that reason hardened-steel poppet and
ball valves are used. These are free from any close
operating clearances. The solenoids operate the
valves directly without any intermediate element.
Direct operation means that these units must have
very high output. They must close against the size-
able flow areas and high line pressures. Fast
response is also required to meet the control require-
ments.
Two of the solenoids are normally-venting and two
are normally-applying; this was done to provide a
default mode of operation. With no electrical power,
the transmission provides 2nd gear in (OD), (3), or
(L) shift lever positions. All other transmission lever
positions will operate normally. The choice of 2nd
gear was made to provide adequate breakaway per-
formance while still accommodating highway speeds.
SENSORS
There are three pressure switches to identify sole-
noid application. There are two speed sensors to read
input (torque converter turbine) and output (parking
sprag) speeds. There is a transmission range sensor
to indicate the manual shift lever position. Also there
is a transmission temperature sensor that is part of
the transmission range sensor. The transmission
temperature sensor measures the fluid temperature
at the tranmission sump. The pressure switches are
incorporated in an assembly with the solenoids.
Engine speed, throttle position, temperature, etc., are
also observed. Some of these signals are read directly
from the engine control sensors; others are read from
a multiplex circuit with the powertrain control mod-
ule.
ELECTRONICS
The 41TE Transmission Control Module (TCM) is
located underhood in a potted, die-cast aluminum
housing. The module used is a new controller called
EATX III. The TCM has a sealed, 60-way connector.
TORQUE CONVERTER CLUTCH CONTROL (TCC)
The EMCC logic enables torque converter clutch to
partially engage between 23 to 47 miles per hour.
Full engagement occurs at about 50 miles per hour.
This feature is on all vehicles equipped with the
41TE transaxle.
ADAPTIVE CONTROLS
These controls function by reading the input and
output speeds over 140 times a second and respond-
ing to each new reading. This provides the precise
and sophisticated friction element control needed to
make smooth clutch-to-clutch shifts for all gear
changes. The use of overrunning clutches or other
shift quality aids are not required. As with most
automatic transaxles, all shifts involve releasing one
element and applying a different element. In simpli-
JX
TRANSAXLE 21 - 3
GENERAL INFORMATION (Continued)