(2) To perform the dipstick tube fluid suction
method, use a suitable fluid suction device (Vaculay
or equivalent).
(3) Insert the fluid suction line into the dipstick
tube.
NOTE: Verify that the suction line is inserted to the
lowest point of the transaxle oil pan. This will
ensure complete evacuation of the fluid in the pan.
(4) Follow the manufacturers recommended proce-
dure and evacuate the fluid from the transaxle.
(5) Remove the suction line from the dipstick tube.
(6) Add 4 Quarts of Mopar ATF Plus 3 Type 7176
transaxle fluid.
(7) Start the engine and allow it to idle for a min-
imum of one minute. With the parking brake applied,
press your foot on the service brake and cycle the
transaxle from park to all gear positions ending in
neutral or park.
(8) Check the transaxle fluid level and add an
appropriate amount to bring the transaxle fluid level
to 3mm (1/8 in.) below the ADD mark on the dip-
stick.
(9) Recheck the fluid level after the transaxle is at
normal operating temperature. The level should be in
the HOT range.
TRANSAXLE OIL PAN DROP METHOD
This procedure involves removing the transaxle oil
pan to drain the transaxle fluid.
(1) Bring the vehicle up to normal operating tem-
perature. Drive the vehicle a minimum of 10 miles.
(2) Raise the vehicle on the hoist.
(3) Loosen the transaxle oil pan and drain the
fluid into a suitable container.
(4) Remove the pan and clean all sealant from the
pan and transaxle mating surfaces. Clean the mag-
net and the inside of the pan.
(5) Apply a 1/8 inch bead of Mopar RTV Sealant to
the mounting flange of the transaxle oil pan. Apply
RTV Sealant to the underside of the attaching bolts.
Attach the oil pan to the transaxle. Tighten the bolts
to 19 N²m (165 in. lbs.).
(6) Lower the vehicle and add 4 Quarts of Mopar
ATF Plus 3 Type 7176 transaxle fluid.
(7) Start the engine and allow it to idle for a min-
imum of one minute. With the parking brake applied,
press your foot on the service brake and cycle the
transaxle from park to all gear positions ending in
neutral or park.
(8) Check the transaxle fluid level and add an
appropriate amount to bring the transaxle fluid level
to 3mm (1/8 in.) below the ADD mark on the dip-
stick.
(9) Recheck the fluid level after the transaxle is at
normal operating temperature. The level should be inthe HOT range. Drive the vehicle a minimum of 10
miles.
(10) Raise the vehicle on the hoist.
(11) Check for leaks around the transaxle oil pan
sealing surfaces.
(12) Recheck the fluid level. The level should be in
the HOT range.
SEVERE USAGE SERVICE
If the vehicle exhibits any of the following symp-
toms, it is recommended that the transaxle oil and
filter be replaced.
²Transaxle oil discolored
²Transaxle oil has high mileage
²Oil feels grimy when rubbed between fingertips
²Poor shift quality
²Delayed gear engagement
²Vehicle shudder between shifts
TRANSAXLE OIL AND FILTER REPLACEMENT
This procedure involves changing the transaxle
fluid and filter, driving the vehicle for 10 miles and
changing the transaxle fluid a second time.
(1) Bring the vehicle up to normal operating tem-
perature. Drive the vehicle a minimum of 10 miles.
(2) Raise the vehicle on the hoist.
(3) Loosen the transaxle oil pan and drain the
fluid into a suitable container.
(4) Remove the pan and clean all sealant from the
pan and transaxle mating surfaces. Clean the mag-
net and the inside of the pan.
(5) Separate the filter and O-ring from the valve
body. Inspect the O-ring for cuts or improper instal-
lation. This could lead to delayed garage shifts.
(6) Install a new filter. Replace the O-ring as nec-
essary.
(7) Apply a 1/8 inch bead of Mopar RTV Sealant to
the mounting flange of the transaxle oil pan. Apply
RTV Sealant to the underside of the attaching bolts.
Attach the oil pan to the transaxle. Tighten the bolts
to 19 N²m (165 in. lbs.).
(8) Lower the vehicle and add 4 Quarts of Mopar
ATF Plus 3 Type 7176 transaxle fluid.
(9) Start the engine and allow it to idle for a min-
imum of one minute. With the parking brake applied,
press your foot on the service brake and cycle the
transaxle from park to all gear positions ending in
neutral or park.
(10) Check the transaxle fluid level and add an
appropriate amount to bring the transaxle fluid level
to 3mm (1/8 in.) below the ADD mark on the dip-
stick.
(11) Recheck the fluid level after the transaxle is
at normal operating temperature. The level should be
in the HOT range. Drive the vehicle a minimum of
10 miles.
(12) Raise the vehicle on the hoist.
NSTRANSAXLE AND POWER TRANSFER UNIT 21 - 17
SERVICE PROCEDURES (Continued)
(13) Remove the pan and clean all sealant from
the pan and transaxle mating surfaces. Clean the
magnet and the inside of the pan.
(14) Separate the filter from the valve body to
allow additional fluid to drain from the transaxle.
Inspect the filter O-ring for any damage and replace
as necessary.
(15) After the transaxle has stopped draining,
reinstall the filter and O-ring.
(16) Apply a 1/8 inch bead of Mopar RTV Sealant
to the mounting flange of the transaxle oil pan.
Apply RTV Sealant to the underside of the attaching
bolts. Attach the oil pan to the transaxle. Tighten the
bolts to 19 N²m (165 in. lbs.).
(17) Lower the vehicle and add 4 Quarts of Mopar
ATF Plus 3 Type 7176 transaxle fluid.
(18) Start the engine and allow it to idle for a min-
imum of one minute. With the parking brake applied,
press your foot on the service brake and cycle the
transaxle from park to all gear positions ending in
neutral or park.
(19) Check the transaxle fluid level and add an
appropriate amount to bring the transaxle fluid level
to 3mm (1/8 in.) below the ADD mark on the dip-
stick.
(20) Recheck the fluid level after the transaxle is
at normal operating temperature. The level should be
in the HOT range.
FLUID DRAIN AND REFILL
(1) Raise vehicle on a hoist (See Group 0, Lubrica-
tion). Place a drain container with a large opening,
under transaxle oil pan.
(2) Loosen pan bolts and tap the pan at one corner
to break it loose allowing fluid to drain, then remove
the oil pan.
(3) Install a new filter and gasket on bottom of the
valve body and tighten retaining screws to 5 N´m (40
inch-pounds).
(4) Clean the oil pan and magnet. Reinstall pan
using new sealant. Tighten oil pan bolts to 19 N´m
(165 in. lbs.).
(5) Pour four quarts of Mopar ATF PLUS 3 (Auto-
matic Transmission Fluid) Type 7176 through the
dipstick opening.
(6) Start engine and allow to idle for at least one
minute. Then, with parking and service brakes
applied, move selector lever momentarily to each
position, ending in the park or neutral position.
(7) Add sufficient fluid to bring level to 1/8 inch
below the ADD mark.
(8) Recheck fluid level after transaxle is at normal
operating temperature. The level should be in the
HOT region.
ALUMINUM THREAD REPAIR
Damaged or worn threads in the aluminum transaxle
case and valve body can be repaired by the use of Heli-
Coils, or equivalent. This repair consists of drilling out
the worn-out damaged threads. Then tapping the hole
with a Heli-Coil tap, or equivalent, and installing a
Heli-Coil insert, or equivalent, into the hole. This
brings the hole back to its original thread size.
Heli-Coil, or equivalent, tools and inserts are readily
available from most automotive parts suppliers.
FLUSHING COOLERS AND TUBES
When a transaxle failure has contaminated the
fluid, the oil cooler(s) must be flushed. The cooler
bypass valve in the transaxle must be replaced also.
The torque converter must also be replaced with an
exchange unit. This will ensure that metal particles
or sludged oil are not later transferred back into the
reconditioned (or replaced) transaxle.
The recommended procedure for flushing the cool-
ers and tubes is to use Tool 6906A Cooler Flusher.
WARNING: WEAR PROTECTIVE EYEWEAR THAT
MEETS THE REQUIREMENTS OF OSHA AND ANSI
Z87.1±1968. WEAR STANDARD INDUSTRIAL RUB-
BER GLOVES.
KEEP LIGHTED CIGARETTES, SPARKS, FLAMES,
AND OTHER IGNITION SOURCES AWAY FROM THE
AREA TO PREVENT THE IGNITION OF COMBUSTI-
BLE LIQUIDS AND GASES. KEEP A CLASS (B) FIRE
EXTINGUISHER IN THE AREA WHERE THE
FLUSHER WILL BE USED.
KEEP THE AREA WELL VENTILATED.
DO NOT LET FLUSHING SOLVENT COME IN CON-
TACT WITH YOUR EYES OR SKIN: IF EYE CONTAM-
INATION OCCURS, FLUSH EYES WITH WATER FOR
15 TO 20 SECONDS. REMOVE CONTAMINATED
CLOTHING AND WASH AFFECTED SKIN WITH
SOAP AND WATER. SEEK MEDICAL ATTENTION.
COOLER FLUSH USING TOOL 6906A
(1) Remove cover plate filler plug on Tool 6906A.
Fill reservoir 1/2 to 3/4 full of fresh flushing solution.
Flushing solvents are petroleum based solutions gen-
erally used to clean automatic transmission compo-
nents.DO NOTuse solvents containing acids, water,
gasoline, or any other corrosive liquids.
(2) Reinstall filler plug on Tool 6906A.
(3) Verify pump power switch is turned OFF. Con-
nect red alligator clip to positive (+) battery post.
Connect black (-) alligator clip to a good ground.
(4) Disconnect the cooler lines at the transmission.
NOTE: When flushing transmission cooler and
lines, ALWAYS reverse flush.
21 - 18 TRANSAXLE AND POWER TRANSFER UNITNS
SERVICE PROCEDURES (Continued)
(5) Connect the BLUE pressure line to the OUT-
LET (From) cooler line.
(6) Connect the CLEAR return line to the INLET
(To) cooler line
(7) Turn pump ON for two to three minutes to
flush cooler(s) and lines. Monitor pressure readings
and clear return lines. Pressure readings should sta-
bilize below 20 psi. for vehicles equipped with a sin-
gle cooler and 30 psi. for vehicles equipped with dual
coolers. If flow is intermittent or exceeds these pres-
sures, replace cooler.
(8) Turn pump OFF.
(9) Disconnect CLEAR suction line from reservoir
at cover plate. Disconnect CLEAR return line at
cover plate, and place it in a drain pan.
(10) Turn pump ON for 30 seconds to purge flush-
ing solution from cooler and lines. Turn pump OFF.
(11) Place CLEAR suction line into a one quart
container of Mopar ATF Plus 3ttype 7176 automatic
transmission fluid.
(12) Turn pump ON until all transmission fluid is
removed from the one quart container and lines. This
purges any residual cleaning solvent from the trans-
mission cooler and lines. Turn pump OFF.
(13) Disconnect alligator clips from battery. Recon-
nect flusher lines to cover plate, and remove flushing
adapters from cooler lines.
OIL PUMP VOLUME CHECK
After the new or repaired transmission has been
installed, fill to the proper level with MopartAT F
PLUS 3 (Type 7176) automatic transmission fluid.
The volume should be checked using the following
procedure:
(1) Disconnect theFrom coolerline at the trans-
mission and place a collecting container under the
disconnected line.
CAUTION: With the fluid set at the proper level,
fluid collection should not exceed (1) quart or inter-
nal damage to the transmission may occur.
(2) Run the engineat curb idle speed, with the
shift selector in neutral.
(3) If fluid flow is intermittent or it takes more
than 20 seconds to collect one quart of ATF PLUS 3,
disconnect theTo Coolerline at the transaxle.
(4) Refill the transaxle to proper level and recheck
pump volume.
(5) If flow is found to be within acceptable limits,
replace the cooler. Then fill transmission to the
proper level, using MopartATF PLUS 3 (Type 7176)
automatic transmission fluid.
(6) If fluid flow is still found to be inadequate,
check the line pressure using the Transaxle Hydrau-
lic Pressure Test procedure.
REMOVAL AND INSTALLATION
VEHICLE SPEED SENSOR PINION GEAR
When the sensor is removed for any reason, a
NEW O-ring must be installed on its outside diame-
ter.
REMOVAL
(1) Remove harness connector from sensor. Make
sure weatherseal stays on harness connector.
(2) Remove bolt securing the sensor in the exten-
sion housing.
(3) Carefully pull sensor and pinion gear assembly
out of extension housing.
(4) Remove pinion gear from sensor.
INSTALLATION
(1) To install, reverse the above procedure. Make
sure extension housing and sensor flange are clean
prior to installation. Always use a NEW sensor
O-ring.
(2) Tighten bolt to 7 N´m (60 in. lbs.). Tighten
speedometer cable to 4 N´m (35 in. lbs.).
PARK/NEUTRAL STARTING AND BACK-UP LAMP
SWITCH
TEST
The park/neutral starting switch is the center ter-
minal of the 3 terminal switch. It provides ground for
the starter solenoid circuit through the selector lever
in only Park and Neutral positions.
(1) To test switch, remove wiring connector from
switch and test for continuity between center pin of
switch and transaxle case. Continuity should exist
only when transaxle is in Park or Neutral.
(2) Check gearshift cable adjustment before replac-
ing a switch which tests bad.
REMOVAL
(1) Unscrew switch from transaxle case allowing
fluid to drain into a container. Move selector lever to
Park, then to Neutral position, and inspect to see the
switch operating lever fingers are centered in switch
opening.
INSTALLATION
(1) Screw the switch with a new seal into tran-
saxle case and tighten to 33 N´m (24 ft. lbs.). Retest
switch with the test lamp.
(2) Add fluid to transaxle to bring up to proper
level.
(3) The back-up lamp switch circuit is through the
two outside terminals of the 3 terminal switch.
(4) To test switch, remove wiring connector from
switch and test for continuity between the two out-
side pins.
NSTRANSAXLE AND POWER TRANSFER UNIT 21 - 19
SERVICE PROCEDURES (Continued)
(5) Continuity should exist only with transaxle in
Reverse position.
(6) No continuity should exist from either pin to
the case.
TRANSAXLE AND TORQUE CONVERTER REMOVAL
NOTE: Transaxle removal does NOT require engine
removal.
The transaxle and torque converter must be
removed as an assembly; otherwise, the torque con-
verter drive plate, pump bushing, or oil seal may be
damaged. The drive plate will not support a load;
therefore, none of the weight of the transaxle should
be allowed to rest on the plate during removal.
REMOVAL
(1) Disconnect negative battery cable.
(2) Remove air cleaner and hoses.
(3) Disconnect throttle linkage and shift linkage
from transaxle.
(4) Unplug torque converter clutch connector,
located near the dipstick. Unplug the gear position
switch.
(5) Remove transaxle dipstick tube.
(6) Remove the transaxle cooler lines and plug.
(7) Install engine support fixture (Fig. 5) .
(8) Remove bell housing upper bolts.
(9) Raise vehicle. Remove front wheels. Refer to
Group 2, Suspension to remove or install wheel hub
nut and both drive shafts.
CAUTION: The exhaust flex joint must be discon-
nected from the exhaust manifold anytime the
engine is lowered. If the engine is lowered while the
flex pipe is attached, damage will occur.(10) Remove bolts securing exhaust flex joint to
exhaust manifold. Disconnect exhaust pipe from
manifold.
(11) Remove torque converter dust cover. Mark
torque converter and drive plate with chalk, for reas-
sembly. Rotate engine clockwise and remove torque
converter mounting bolts.
(12) Remove engine mount bracket from front
crossmember.
(13) Remove front mount insulator through-bolt
and bellhousing bolts.
(14) Position transaxle jack (Fig. 6) .
(15) Remove rear engine mount shield.
(16) Remove rear engine mount bracket bolts and
bracket.
(17) Remove left engine mount thru-bolt.
(18) Remove left engine mount from transaxle.
(19) Remove starter. Remove lower bell housing
bolts.
(20) Carefully work transaxle and torque converter
assembly rearward off engine block dowels and dis-
engage converter hub from end of crankshaft.Attach
a small C clamp to edge of bell housing. This
will hold torque converter in place during tran-
saxle removal.Lower transaxle and remove assem-
bly from under the vehicle.
(21) To remove torque converter assembly, remove
C±clamp from edge of bellhousing and slide converter
out of transaxle.
INSTALLATION
(1) When installing transaxle, reverse the above
procedure.
(2) If torque converter was removed from transaxle
be sure to align pump inner gear pilot flats with
torque converter impeller hub flats.
(3) Adjust gearshift and throttle cables.
(4) Refill transaxle with Mopar ATF PLUS 3
(Automatic Transmission Fluid) Type 7176.
Fig. 5 Engine Support Fixture
Fig. 6 Transaxle Jack
21 - 20 TRANSAXLE AND POWER TRANSFER UNITNS
REMOVAL AND INSTALLATION (Continued)
Inspect all valve springs for distortion and col-
lapsed coils. Inspect all valves and plugs for burrs,
nicks, and scores. Small nicks and scores may be
removed with crocus cloth, providing extreme care is
taken not to round off sharp edges. The sharpness of
these edges is vitally important. It prevents foreign
matter from lodging between valve and valve body.
This reduces the possibility of sticking. Inspect all
valves and plugs for freedom of operation in valve
body bores.
When bores, valves, and plugs are clean and dry,
the valves and plugs should fall freely in the bores.
The valve body bores do not change its dimensions
with use. Therefore, a valve body that was function-
ing properly when vehicle was new, will operate cor-
rectly if it is properly and thoroughly cleaned. There
is no need to replace valve body unless it is damaged
in handling.
ADJUSTMENTS
GEARSHIFT CABLE ADJUSTMENT
Lift and rotate the gearshift hand lever into the
park (P) gate position and remove the ignition key.
This confirms the shift lever is in the gated park (P)
position.
After confirming the park gate position, turn the
ignition switch. If the starter will operate, the park
gate position is correct. Move the shift lever into the
neutral (N) position. If the starter will operate in this
position, the linkage is properly adjusted. If the
starter fails to operate in either position, linkage
adjustment is required.
(1) Park the vehicle on level ground and set the
parking brake.
(2) Place the gearshift lever in park (P) gate posi-
tion and remove key.
(3) Loosen the cable adjustment screw at the tran-
saxle operating lever (Fig. 160).
(4) Pull the transaxle operating lever fully forward
to the park detent position.
(5) Release the park brake, then rock the vehicle
to assure it is in park lock. Reset the park brake.
(6) Tighten the cable adjustment screw to 8 N´m
(70 in. lbs.). Gearshift cable should now be properly
adjusted.
(7) Verify PRNDL indicator still displays the corre-
sponding gear completely. If not, readjustment of
PRNDL may be required.
(8) Check adjustment by using the preceding pro-
cedure.
THROTTLE PRESSURE LINKAGE ADJUSTMENT
The throttle pressure rod adjustment is very
important to proper transaxle operation. This adjust-
ment positions a valve which controls shift speed,shift quality, and part throttle downshift sensitivity.
If the setting is too short, early shifts and slippage
between shifts may occur. If the setting is too long,
shifts may be delayed and part throttle downshifts
may be very sensitive.
With engine at operating temperature, adjust idle
speed of engine using a tachometer. Refer to Group
14, Fuel System for idle speed Specifications and
adjustment.
ROD ADJUSTMENT PROCEDURE
(1) Perform transaxle throttle pressure adjustment
while engine is at normal operating temperature.
(2) Loosen adjustment swivel lock screw.
(3) To insure proper adjustment, swivel must be
free to slide along flat end of throttle rod. Disassem-
ble and clean or repair parts to assure free action, if
necessary.
(4) Hold transaxle throttle lever firmly toward
engine, against its internal stop. Tighten swivel lock
screw to 11 N´m (100 in. lbs.)
(5) The adjustment is finished and linkage back-
lash was automatically removed by the preload
spring.
(6) I
f lubrication is required see Group 0, Lubrica-
tion.
BAND ADJUSTMENT
KICKDOWN BAND (FRONT)
The kickdown band adjusting screw is located on
left side (top front) of the transaxle case.
(1) Loosen locknut and back off nut approximately
five turns. Test adjusting screw for free turning in
the transaxle case.
(2) Using wrench, tighten adjusting screw to 8
N´m (72 in. lbs.).
Fig. 160 Gearshift Cable Adjustment
NSTRANSAXLE AND POWER TRANSFER UNIT 21 - 51
CLEANING AND INSPECTION (Continued)
OPERATION
The gear ratios for the 41TE transaxle are as fol-
lows:
²1stÐ2.84
²2ndÐ1.57
²3rdÐ1.00
²ODÐ0.69
²ReverseÐ2.21
Final Drive Ratio is dependent on which engine
option is selected.
²2.4 Liter: 3.91 FDR
²3.3 Liter: 3.62 FDR
²3.8 Liter: 3.45 FDR
The torque converter clutch is available in 2nd,
direct, or overdrive gear;. The shift lever is conven-
tional with six positions: P, R, N, OD, 3, and L avail-
able. When OD is selected the transaxle shifts
through all four speeds with torque converter clutch
available in overdrive. This position is recommended
for most driving. The 3 position is tailored for use in
hilly or mountainous driving. When 3 is selected, the
transmission uses only 1st, 2nd, and direct gears
with 2nd-direct shift delayed to 40 mph or greater.
When operating in 3 or L positions torque converter
clutch application occurs in direct gear. This
improves transmission cooling under heavy loads. If
high engine coolant temperature occurs, the torque
converter clutch will also engage in 2nd gear. The L
position provides maximum engine braking for
descending steep grades. Unlike most current tran-
saxles, upshifts are provided to 2nd or direct gear at
peak engine speeds if the accelerator is depressed.
This provides engine over-speed protection and max-
imum performance.
FLUID LEVEL AND CONDITION
NOTE: The transmission and differential sump have
a common oil sump with an opening between the
two.
The torque converter fills in both the (P) Park and
(N) Neutral positions. Place the selector lever in (P)
Park to check the fluid level.The engine should be
running at idle speed for at least one minute,
with the vehicle on level ground. This will
assure complete oil level stabilization between
differential and transmission.The fluid should be
at normal operating temperature (approximately 82
C. or 180 F.). The fluid level is correct if it is in the
HOTregion (cross-hatched area) on the oil level indi-
cator.
Low fluid level can cause a variety of conditions
because it allows the pump to take in air along with
the fluid. As in any hydraulic system, air bubbles
make the fluid spongy, therefore, pressures will be
low and build up slowly.Improper filling can also raise the fluid level too
high. When the transaxle has too much fluid, the
gears churn up foam and cause the same conditions
which occur with a low fluid level.
In either case, the air bubbles can cause overheat-
ing, fluid oxidation, and varnishing. This can inter-
fere with normal valve, clutch, and accumulator
operation. Foaming can also result in fluid escaping
from the transaxle vent where it may be mistaken
for a leak.
Along with fluid level, it is important to check the
condition of the fluid. When the fluid smells burned,
and is contaminated with metal or friction material
particles, a complete transaxle overhaul is needed.
Be sure to examine the fluid on the dipstick closely.
If there is any doubt about its condition, drain out a
sample for a double check.
After the fluid has been checked, seat the dipstick
fully to seal out water and dirt.
SELECTION OF LUBRICANT
It is important that the proper lubricant be used in
the 41TE transaxle. MOPARtATF PLUS 3 (Auto-
matic Transmission FluidÐtype 7176) should be used
to aid in assuring optimum transmission perfor-
mance. Fluids of the type labeled DEXRON II Auto-
matic Transmission Fluid arenot recommended.It
is important that the transmission fluid be main-
tained at the prescribed level using the recommended
fluids.
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:
²Three multiple disc input clutches
²Two multiple disc grounded clutches
²Four hydraulic accumulators
²Two planetary gear sets
This provides four forward ratios and a reverse
ratio. The input 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.
21 - 72 TRANSAXLE AND POWER TRANSFER UNITNS
GENERAL INFORMATION (Continued)
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:
²Manual shift lever select function
²Main line pressure regulation
²Torque 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 TCC control 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 also a transmission range
sensor to indicate the manual shift lever position.
The pressure switches are incorporated in an assem-
bly with the solenoids. Engine speed, throttle posi-tion, temperature, etc., are also observed. Some of
these signals are read directly from the engine con-
trol sensors; others are read from a multiplex circuit
with the powertrain control module.
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.
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-
fied terms, the upshift logic allows the releasing ele-
ment to slip backwards slightly. This ensures that it
does not have excess capacity. The apply element is
filled until it begins to make the speed change to the
higher gear. The apply pressure is then controlled to
maintain the desired rate of speed change. This con-
tinues until the shift is made. The key to providing
excellent shift quality is precision. For example, the
release element for upshifts is allowed to slip back-
wards slightly. The amount of that slip is typically
less than a total of 20 degrees. To achieve that pre-
cision, the TCM learns the traits of the transaxle
that it is controlling. It learns the release rate of the
releasing element and the apply time of the applying
element. It also learns the rate at which the apply
element builds pressure sufficient to begin making
the speed change. This method achieves more preci-
sion than would be possible with exacting tolerances.
It can also adapt to any changes that occur with age
or environment.
For kickdown shifts, the control logic allows the
releasing element to slip. Then controls the rate at
which the input (and engine) accelerate. When the
lower gear speed is achieved, the releasing element
reapplies to maintain that speed until the apply ele-
ment is filled. This provides quick response since the
engine begins to accelerate immediately. This also
provides a smooth torque exchange since the release
element can control the rate of torque increase. This
control can make any powertrain feel more respon-
sive without increasing harshness.
Adaptive controls respond to input speed changes.
They compensate for changes in engine or friction
element torque and provide good, consistent shift
quality for the life of the transaxle.
NSTRANSAXLE AND POWER TRANSFER UNIT 21 - 73
DESCRIPTION AND OPERATION (Continued)
REVERSE CLUTCH
Apply air pressure to the reverse clutch apply pas-
sage and watch for the push/pull piston to move rear-
ward. The piston should return to its starting
position when the air pressure is removed.
2/4 CLUTCH
Apply air pressure to the feed hole located on the
2/4 clutch retainer. Look in the area where the 2/4
piston contacts the first separator plate and watch
carefully for the 2/4 piston to move rearward. The
piston should return to its original position after the
air pressure is removed.
LOW/REVERSE CLUTCH
Apply air pressure to the low/reverse clutch feed
hole (rear of case, between 2 bolt holes). Then, look
in the area where the low/reverse piston contacts thefirst separator plate. Watch carefully for the piston to
move forward. The piston should return to its origi-
nal position after the air pressure is removed.
UNDERDRIVE CLUTCH
Because this clutch piston cannot be seen, its oper-
ation is checked by function. Air pressure is applied
to the low/reverse and the 2/4 clutches. This locks the
output shaft. Use a piece of rubber hose wrapped
around the input shaft and a pair of clamp-on pliers
to turn the input shaft. Next apply air pressure to
the underdrive clutch. The input shaft should not
rotate with hand torque. Release the air pressure
and confirm that the input shaft will rotate.
FLUID LEAKAGE-TORQUE CONVERTER HOUSING
AREA
(1) Check for source of leakage.
(2) Fluid leakage at or around the torque converter
area may originate from an engine oil leak. The area
should be examined closely. Factory fill fluid is red
and, therefore, can be distinguished from engine oil.
(3) Prior to removing the transaxle, perform the
following checks:
(4) When leakage is determined to originate from
the transaxle, check fluid level prior to removal of
the transaxle and torque converter.
(5) High oil level can result in oil leakage out the
vent in the manual shaft. If the fluid level is high,
adjust to proper level.
(6) After performing this operation, inspect for
leakage. If a leak persists, perform the following
operation on the vehicle. This will determine if the
torque converter or transaxle is leaking.
TORQUE CONVERTER LEAKAGE
Possible sources of torque converter leakage are:
²Torque converter weld leaks at the outside
(peripheral) weld.
²Torque converter hub weld.
NOTE: Hub weld is inside and not visible. Do not
attempt to repair. Replace torque converter.
SHIFT POSITION INDICATOR
The transmission range sensor (on the valve body)
sends a signal to the TCM on the position of the
transaxle manual valve lever. The TCM receives the
switch signal and processes the data. The TCM sends
the Shift Lever Position (SLP) information to the
BCM via the CCD bus. The BCM then outlines with
a box the appropriate shifter position indicator in the
instrument cluster.
Fig. 3 Air Pressure Test Plate
Fig. 4 Testing Reverse Clutch
21 - 78 TRANSAXLE AND POWER TRANSFER UNITNS
DIAGNOSIS AND TESTING (Continued)