1993 CHEVROLET DYNASTY engine

OPERATION
The 41TE transaxle provides forward ratios of 2.84,
1.57, 1.00, and 0.69 with torque converter clutch
available in 2nd, direct, or overdrive gear; the Re-
verse ratio is 2.21. The shift lever is conventional
with six positions: P, R, N, OD, 3, and L. When OD
is selected the transaxle shifts normally 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 trans-
mission 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 for improved trans-
mission 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 transaxles, up-
shifts are provided to 2nd or direct gear at peak en-
gine speeds if the accelerator is depressed. This
provides engine over-speed protection and maximum
performance.
CLUTCH AND GEAR
The transaxle consists of:
² Three multiple disc input clutches
² Two multiple disc grounded clutches
² Four hydraulic accumulators
² Two planetary gear sets
This provides four forward ratios and a reverse ra-
tio. The clutch-apply pistons were designed with cen-
trifugally 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 the manual
shift lever select function, main line pressure regula-
tion, and 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 converter
clutch control valve''. This valve locks out the 1st
gear reaction element with the application of 2nd, di-
rect, 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 special sequence of solenoid commands must
be used to unlock and move the solenoid torque con-
verter clutch control valve. This precludes any appli- cation of the 1st gear reaction element with other
elements applied. It also allows one solenoid to con-
trol two friction elements.
Small, high-rate accumulators are provided in each
controlled friction element circuit. These serve to ab-
sorb the pressure responses, and allow the controls to
read and respond to changes that are occurring.
SOLENOIDS
Since the solenoid valves perform virtually all con-
trol functions, these valves must be extremely dura-
ble and tolerant of normal dirt particles. For that
reason hardened-steel poppet and ball valves are
used. These are free from any close operating clear-
ances, and the solenoids operate the valves directly
without any intermediate element. Direct operation
means that these units must have very high output
so that they can close against the sizeable flow areas
and high line pressures. Fast response is also re-
quired to meet the control requirements. Two of the solenoids are normally-venting and two
are normally-applying; this was done to provide a de-
fault mode of operation. With no electrical power, the
transmission provides 2nd gear in OD, 3,orLshift
lever positions. All other transmission lever positions
will operate normally. The choice of 2nd gear was
made to provide adequate breakaway performance
while still accommodating highway speeds.
SENSORS
There are three pressure switches to identify sole-
noid application and two speed sensors to read input
(torque converter turbine) and output (parking sprag)
speeds. There is also a position switch to indicate the
manual shift lever position. 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 is located
underhood in a potted, die-cast aluminum housing
with a sealed, 60-way connector.
ELECTRONIC MODULATED CONVERTER CLUTCH (EMCC)
The EMCC enables the torque converter clutch to
partially engage between 23 to 47 MPH before full
engagement at about 50 MPH and beyond. This fea-
ture is on all vehicles equipped with the 41TE tran-
saxle.
ADAPTIVE CONTROLS
These controls function by reading the input and
output speeds over 140 times a second and respond-
Ä TRANSAXLE 21 - 87

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 au-
tomatic transaxles, all shifts involve releasing one el-
ement and applying a different element. In simplified
terms, the upshift logic allows the releasing element
to slip back wards slightly to ensure that it does not
have excess capacity; the apply element is filled until
it begins to make the speed change to the higher
gear; its apply pressure is then controlled to main-
tain the desired rate of speed change until the shift
is complete. The key to providing excellent shift
quality is precision; for example, as mentioned, 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 transmission control module learns the
characteristics of the particular 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 precision than
would be possible with exacting tolerances. It can
also adapt to any changes that occur with age or en-
vironment, for example, altitude, temperature, en-
gine output, etc. For kickdown shifts, the control logic allows the re-
leasing element to slip and 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 and a
smooth torque exchange since the release element
can control the rate of torque increase. This control
can make any powertrain feel more responsive with-
out in creasing harshness. Adaptive controls respond to input speed changes. They compensate for changes in engine or friction el-
ement torque and provide good, consistent shift qual-
ity for the life of the transaxle.
ON-BOARD DIAGNOSTICS
These controls provide comprehensive, on-board
transaxle diagnostics. The information available can
aid in transaxle diagnosis. For example, apply ele-
ment buildup rate indicates solenoid performance.
Also included are self diagnostic functions. Self diag-
nostics allow the technician to test the condition of
the electronic controls. The transmission control
module continuously monitors its critical functions.
It also records any malfunctions, and the number of
engine starts since the last malfunction. This allows
the technician to use the information in the event of
a customer complaint.
41TE TRANSAXLE GENERAL DIAGNOSIS
CAUTION: Before attempting any repair on a 41TE
four speed automatic transaxle, check for diagnos-
tic trouble codes with the DRB II scan tool. Always
use the Powertrain Diagnostic Test Procedure Man-
ual.
Transaxle malfunctions may be caused by these
general conditions:
² Poor engine performance
² Improper adjustments
² Hydraulic malfunctions
² Mechanical malfunctions
² Electronic malfunctions
Diagnosis of these problems should always begin
by checking the easily accessible variables: fluid
level and condition, gearshift cable adjustment. Then
perform a road test to determine if the problem has
been corrected or that more diagnosis is necessary. If
the problem exists after the preliminary tests and
corrections are completed, hydraulic pressure checks
should be performed.
21 - 88 TRANSAXLE Ä

FLUID LEVEL AND CONDITION
The transmission and differential sump have a
common oil sump with a communicating opening
between the two. The torque converter fills in both the PPark and N
Neutral positions. Place the selector lever in PPark 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 com-
plete 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 indicator. 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 over heat-
ing, fluid oxidation, and varnishing, which can inter-
fere with normal valve, clutch, and accumulator opera-
tion. 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. MOPAR tATF PLUS (Automatic
Transmission FluidÐtype 7176) should be used to aid
in assuring optimum transmission performance. Flu-
ids of the type labeled DEXRON II Automatic Trans-
mission Fluid are not recommended . DEXRON II
can be used only if the recommended fluid is not
available. If more than a small amount of DEXRON II
is used shudder or shift quality problems may result. It
is important that the transmission fluid be maintained
at the prescribed level using the recommended fluids.
SPECIAL ADDITIVES
Chrysler Corporation does not recommend the addi-
tion of any fluids to the transaxle, other than the
automatic transmission fluid listed above. An excep- tion 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.
FLUID AND FILTER CHANGES
When the factory fill fluid is changed, only fluids
labeled MOPAR tATF PLUS (Automatic Transmis-
sion fluid) Type 7176 should be used. A filter change
should be made at the time of the oil change. Also
the magnet (on the inside of the oil pan) should be
cleaned with a clean, dry cloth. If the transaxle is disassembled for any reason, the
fluid and filter should be changed.
FLUID DRAIN AND REFILL
(1) Raise vehicle on a hoist (See Lubrication,
Group 0). Place a drain container with a large open-
ing, 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 O-ring on bottom of the
valve body. (4) Clean the oil pan and magnet. Reinstall pan
using new MOPAR tAdhesive Sealant. Tighten oil
pan bolts to 19 N Im (165 in. lbs.).
(5) Pour four quarts of MOPAR tATF PLUS (Au-
tomatic Transmission Fluid) Type 7176 through the
fill tube. (6) Start engine and allow to idle for at least one
minute. Then, with parking and service brakes ap-
plied, move selector lever momentarily to each posi-
tion, ending in the park or neutral position. (7) Add sufficient fluid to bring level to 1/8 inch
below the ADD mark. Recheck fluid level after transaxle is at normal op-
erating temperature. The level should be in the HOT
region (Fig. 3).
To prevent dirt from entering transaxle, make cer-
tain that dipstick is seated into the dipstick fill tube
(Fig. 4).
ROAD TEST
Prior to performing a road test, be certain that the
fluid level and condition, and control cable adjust-
ment have been checked and approved.
Fig. 3 Oil Level Indicator
Ä TRANSAXLE 21 - 93

During the road test, the transaxle should be oper-
ated in each position to check for slipping and any
variation in shifting. If vehicle operates properly at highway speeds, but
has poor acceleration, the torque converter stator
overrunning clutch may be slipping. If through-gear
acceleration is normal, but high throttle opening is
required to maintain highway speeds, the torque con-
verter stator clutch may have seized. Both of these
stator defects require replacement of the torque con-
verter. The clutch that is slipping can be determined by
noting the transaxle operation in all selector posi-
tions. Then comparing which internal units are ap-
plied in those positions. The Elements in Use Chart
provides a basis for road test analysis. The process of elimination can be used to detect
any unit which slips and to confirm proper operation
of good units. Road test analysis can usually diag-
nose slipping units, but the actual cause of the mal-
function usually can not be decided. Practically any
condition can be caused by leaking hydraulic circuits
or sticking valves.
HYDRAULIC PRESSURE TESTS
Pressure testing is a very important step in the di-
agnostic procedure. These tests usually reveal the
cause of most transaxle problems. Before performing pressure tests, be certain that
fluid level and condition, and shift cable adjustments
have been checked and approved. Fluid must be at
operating temperature (150 to 200 degrees F.). Install an engine tachometer, raise vehicle on hoist
which allows front wheels to turn, and position ta-
chometer so it can be read. Attach 150 psi gauges to ports required for test be-
ing conducted. A 300 psi gauge (C-3293) is required
for reverse pressure test. Test port locations are shown in (Figure 1).
TEST ONE-SELECTOR IN LOW 1ST GEAR
(1) Attach pressure gauge to the low/reverse clutch
tap. (2) Move selector lever to the L position.
(3) Allow vehicle wheels to turn and increase
throttle opening to achieve an indicated vehicle
speed to 20 mph. (4) Low/reverse clutch pressure should read 115 to
145 psi.
ELEMENTS IN USE AT EACH POSITION OF THE SELECTOR LEVER
Fig. 4 Oil Level Indicator Location
21 - 94 TRANSAXLE Ä

first separator plate and watch carefully for the pis-
ton to move forward. The piston should return to its
original 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 ro-
tate 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.
Since fluid leakage at or around the torque con-
verter area may originate from an engine oil leak,
the area should be examined closely. Factory fill
fluid is dyed red and, therefore, can be distinguished
from engine oil. (2) Prior to removing the transaxle, perform the
following checks: When leakage is determined to originate from the
transaxle, check fluid level prior to removal of the
transaxle and torque converter. 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. After performing this operation, inspect for leak-
age. If a leak persists, perform the following opera-
tion on the vehicle to determine if it is the torque
converter or transaxle that is leaking.
LEAKAGE TEST PROBE
(1) Remove torque converter housing dust shield.
(2) Clean the inside of torque converter housing
(lower area) as dry as possible. A solvent spray fol-
lowed by compressed air drying is preferable. (3) Fabricate and fasten test probe (Fig. 4) securely
to convenient dust shield bolt hole. Make certain
torque converter is cleared by test probe. Tool must be
clean and dry. (4) Run engine at approximately 2,500 rpm with
transaxle in neutral, for about 2 minutes. Transaxle
must be at operating temperature. (5) Stop engine and carefully remove tool.
(6) If upper surface of test probe is dry, there is no
torque converter leak. A path of fluid across probe
indicates a torque converter leak. Oil leaking under the
probe is coming from the transaxle torque converter
area. (7) Remove transaxle and torque converter assembly
from vehicle for further investigation. The fluid should
be drained from the transaxle. Re install oil pan (with
MOPAR tAdhesive Sealant) at specified torque.
Possible sources of transaxle torque converter area
fluid leakage are: (1) Torque converter hub seal.
² Seal lip cut, check torque converter hub finish.
² Bushing moved and/or worn.
² Oil return hole in pump housing plugged or omitted.
² Seal worn out (high-mileage vehicles).
(2) Fluid leakage at the outside diameter from pump
housing O-ring. (3) Fluid leakage at the front pump to case bolts.
Check condition of washers on bolts and use new bolts,
if necessary. (4) Fluid leakage due to case or front pump housing
porosity.
TORQUE CONVERTER LEAKAGE
Possible sources of torque converter leakage are:
² Torque converter weld leaks at the out side (periph-
eral) weld.
² Torque converter hub weld.
Hub weld is inside and not visible. Do not
attempt to repair. Replace torque converter. If the torque converter must be replaced, refer
to Torque Converter Clutch Break-in Procedure
in this section. This procedure will reset the
transmission control module break-in status.
Failure to perform this procedure may cause
transaxle shutter.
AIR PRESSURE TEST OF TRANSAXLE
Fabricate equipment needed for test as shown in
Figures 5 and 6. The transaxle should be prepared for pressure test as
follows after removal of the torque converter: (1) Plug dipstick tube and plug oil cooler line fitting.
Remove vent from manual shaft and in stall a 1/8 inch
pipe plug.Fig. 4 Leak Locating Test Probe Tool
Ä TRANSAXLE 21 - 97

CAUTION: If the vehicle is equipped with two oil
coolers (one in the radiator tank, one in front of the
radiator) they must be flushed separately. Do not
attempt to flush both coolers at one time. (1) Disconnect the cooler lines at the transmission.
(2) Using a hand suction gun filled with mineral
spirits, reverse flush the cooler. Force mineral spirits
into the From Cooler line of the cooler (Fig. 7) and
catch the exiting spirits from the To Coolerline.
Observe for the presence of debris in the exiting
fluid. Continue until fluid exiting is clear and free
from debris.
(3) Using compressed air in intermittent spurts,
blow any remaining mineral spirits from the cooler,
again in the reverse direction. (4) To remove any remaining mineral spirits from
the cooler, one (1) quart of automatic transmission
fluid should be pumped through the cooler before re-
connecting. (5) If at any stage of the cleaning process, the
cooler does not freely pass fluid, the cooler must be
replaced.
OIL COOLER FLOW CHECK
After the new or repaired transmission has been
installed, filled to the proper level with automatic
transmission fluid. The flow should be checked using
the following procedure: (1) Disconnect the From coolerline at the trans-
mission and place a collecting container under the
disconnected line. (2) Run the engine at curb idle speed , with the
shift selector in neutral. (3) If the fluid flow is intermittent or it takes more
than 20 seconds to collect one quart of automatic
transmission fluid, the cooler should be replaced. 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.
(4) If flow is found to be within acceptable limits,
reconnect the cooler line. Then fill transmission to
the proper level, using the approved type of auto-
matic transmission fluid.
TRANSAXLE REMOVAL AND INSTALLATION
Transaxle removal does NOT require engine re-
moval. See Group 7-Cooling, to drain engine cooling sys-
tem and remove coolant return extension (3.0 liter
engine only). (1) The transaxle and torque converter must be re-
moved 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 drive plate during removal. (2) Disconnect negative battery cable.
(3) Disconnect transaxle shift linkage.
(4) Install engine support fixture and support en-
gine (Fig.1).
(5) Remove upper bell housing upper bolts.
(6) Raise vehicle. Remove front wheels. Refer to
Suspension, Group 2 to remove wheel hub nut and
both drive shafts. (7) Remove left plastic splash to gain access to the
transaxle (Fig. 2). (8) Remove torque converter dust shield to gain ac-
cess to torque converter bolts (Fig. 3). (9) Mark torque converter and drive plate with
chalk, for reassembly. Remove torque converter
mounting bolts. (10) Disconnect electrical connectors at transmis-
sion range switch and Park/Neutral Position Switch
(Fig. 4).
Fig. 7 Cooler Line Location
Fig. 1 Engine Support Fixture (Typical)
Ä TRANSAXLE 21 - 99

(11) Remove front engine mount insulator and
bracket (Fig. 5). (12) On vehicles equipped with D.I.S. ignition sys-
tem, remove crankshaft position sensor from bell
housing. For installation procedure refer to section
8D of this service manual.
CAUTION: Failure to remove the crankshaft position
sensor from the bell housing could damage the
sensor or torque converter drive plate during trans-
mission removal or installation.
(13) Remove starter bolts and set starter aside. Do
not allow the starter to hang from battery cable (Fig.
6). (14) Position transmission jack securely under
transaxle (Fig. 7). (15) With transmission jack in position, remove
the left transmission mount (Fig. 8). (17) Carefully lower the transaxle assembly from
vehicle (Fig. 9). When installing transaxle, reverse the above proce-
dure.
Fig. 2 Remove Left Splash Shield
Fig. 3 Remove Torque Converter Dust Shield
Fig. 4 Disconnect transmission range switch and Park/Neutral Position Switch
Fig. 5 Remove Front Engine Mount
21 - 100 TRANSAXLE Ä

SPEED SENSOR-OUTPUT
CAUTION: When disconnecting speed sensor con-
nector, be sure that the weather seal does not fall
off or remain in old sensor. The output speed sensor is located to the left of the
manual shift lever (Fig. 8).
TRANSMISSION CONTROL MODULE
When replacing a transmission control module, do
not interchange transmission control modules with
previous year transmission control modules. If a
same year transmission control module is being used
from a different vehicle, the following procedures
must be performed before operating the transaxle:
² Quick Learn Procedure
² Torque Converter Clutch Break-in Procedure
² Electronic Pinion Procedure
The transmission control module is located on the
passenger side of the engine compartment. It is held
in place by four mounting screws. If the transmission control module has been
replaced, the following procedures must be per-
formed:
² ``Quick Learn Procedure''. This procedure will al-
low the transmission control module to learn the
characteristics of the vehicle.
² ``Electronic Pinion Procedure''. This procedure will
reprogram settings within the transmission control
module to compensate for different tire sizes and fi-
nal drive ratios.
² ``Converter Clutch Break-In Procedure'' This proce-
dure will reset the torque converter clutch status.
REMOVAL AND INSTALLATION
(1) Loosen 60 way retaining screw, located in the
center of the 60 way connector. Then disconnect the
60 way connector on transmission control module. (2) Remove transmission control module mounting
screws and lift module from vehicle. To install, reverse removal procedure.
TRANSAXLE QUICK LEARN PROCEDURE
The quick learn procedure requires the use of the
DRB II scan tool and the 1993 DRB II scan tool car-
tridge. This program allows the electronic transaxle sys-
tem to recelebrate itself to provide the best possible
transaxle operation. The quick learn procedure
should be performed if any of the following proce-
dures are performed:
² Transaxle Assembly Replacement
² Transmission Control Module Replacement
² Solenoid Pack Replacement
² Clutch Plate and/or Seal Replacement
² Valve Body Replacement or Recondition
(1) Plug the DRB II scan tool into the blue CCD
Buss connector. The connector is located under the
instrument panel on the drivers side of the vehicle. (2) Insert the 1993 DRB II scan tool cartridge into
the DRB II scan tool. (3) The red and green lights on the DRB II scan
tool will light up and then begin flashing. Wait until
the lights stop flashing before continuing with this
procedure. (4) Press the number 4 key on the DRB II scan
tool key pad. Item number 4 will not appear on the
DRB II scan tool screen unless you scroll down. It is
not necessary to scroll down to be able to choose item
4. (5) Press the number 2 on the DRB II scan tool
key pad (Transmission). (6) Press the number 1 on the DRB II scan tool
key pad. Wait for the DRB II scan tool to perform the
following three tests before continuing (These tests
are done automatically by the DRB II scan tool).
² Buss Test
² Initialize
² Controller Part Number
Fig. 7 Park/Neutral Position Switch
Fig. 8 Output Speed Sensor
Ä TRANSAXLE 21 - 103