Page 1473 of 1938

STEERING
CONTENTS
page
POWER STEERINGÐ2.5L VM DIESEL....... 1
POWER STEERINGÐ2.5L VM DIESEL
INDEX
page page
GENERAL INFORMATION
POWER STEERING GEAR................ 1
POWER STEERING PUMP................ 1
STEERING GEAR OPERATIONÐRHD & LHD
VEHICLES........................... 1SERVICE PROCEDURES
POWER STEERING PUMP ± INITIAL
OPERATION.......................... 1
REMOVAL AND INSTALLATION
POWER STEERING PUMPÐ2.5L DIESEL..... 2
GENERAL INFORMATION
POWER STEERING PUMP
The power steering pump used with the 2.5L VM
Diesel engine operates the same way as the power
steering pump used with the 2.5/4.0L gasoline
engines. Refer to the Description and Operation sec-
tion for the 2.5/4.0L gasoline engine power steering
pump for more information.
STEERING GEAR OPERATIONÐRHD & LHD
VEHICLES
NOTE: The power steering gear should NOT be ser-
viced or adjusted. If a malfunction or oil leak
occurs, the complete steering gear should be
replaced.
Refer to the Power Steering Gear in group 19 for
more information
POWER STEERING GEAR
SERVICE PROCEDURES
POWER STEERING PUMP ± INITIAL OPERATION
WARNING: THE FLUID LEVEL SHOULD BE
CHECKED WITH ENGINE OFF TO PREVENT INJURY
FROM MOVING COMPONENTS.CAUTION: Use MOPAR Power Steering Fluid or
equivalent. Do not use automatic transmission fluid
and do not overfill.
Wipe filler cap clean, then check the fluid level.
The dipstick should indicateCOLDwhen the fluid is
at normal temperature.
(1) Fill the pump fluid reservoir to the proper level
and let the fluid settle for at least two minutes.
(2) Start the engine and let run for a few seconds
then turn engine off.
(3) Add fluid if necessary. Repeat the above proce-
dure until the fluid level remains constant after run-
ning the engine.
Fig. 1 Power Steering GearÐRHD Vehicles
NS/GSSTEERING 19 - 1
Page 1474 of 1938

(4) Raise the front wheels off the ground.
(5) Slowly turn the steering wheel right and left,
lightly contacting the wheel stops at least 20 times.
(6) Check the fluid level add if necessary.
(7) Lower the vehicle, start the engine and turn
the steering wheel slowly from lock to lock.
(8) Stop the engine and check the fluid level and
refill as required.
(9) If the fluid is extremely foamy or milky look-
ing, allow the vehicle to stand a few minutes and
repeat the procedure.
CAUTION: Do not run a vehicle with foamy fluid for
an extended period. This may cause pump damage.
REMOVAL AND INSTALLATION
POWER STEERING PUMPÐ2.5L DIESEL
NOTE: The power steering pump is mounted below
the fuel pump on the left side of the engine. The
vehicle should be raised on a hoist to access the
pump from below.
REMOVAL
(1) Remove serpentine drive belt. Refer to Group 7,
Cooling System, for procedure.
(2) Remove power steering pump pulley. Use a hex
wrench to secure the power steering shaft while
removing the pulley bolt with a box wrench. (Fig. 2)
CAUTION: Do not use an impact wrench to remove
the pump pulley ± this can cause rear pump seal
damage. Do not secure power steering shaft with a
wrench on the coupling to the A/C compressor ±
this can cause rear pump seal damage.
(3) Remove coupling bolts (2) from A/C compressor
side of coupling.
(4) Loosen A/C compressor bolts and separate com-
pressor from bracket. Do not disconnect A/C hoses.
(5) Remove bolts (2) securing the power steering
pump to the power steering bracket.
(6) Disconnect power steering pump supply hose at
the pump and drain fluid.
(7) Disconnect power steering pressure hose at the
steering gear assembly.
(8) Remove power steering pump.
INSTALLATION
(1) Install pump on engine.
(2) Tighten pump bracket bolts to 47 N´m (35 ft.
lbs.).(3) Reverse the above procedures in steps 8
through 1 to complete installation.
(4) Add power steering fluid and perform Power
Steering Pump Initial Operation.
Fig. 2 Power Steering Pump Pulley Removal
Fig. 3 Left SIde Motor MountÐVM DIesel
19 - 2 STEERINGNS/GS
SERVICE PROCEDURES (Continued)
Page 1475 of 1938

TRANSAXLE AND POWER TRANSFER UNIT
CONTENTS
page page
31TH AUTOMATIC TRANSAXLE.............. 1
41TE AUTOMATIC TRANSAXLE............. 71POWER TRANSFER UNIT................. 165
31TH AUTOMATIC TRANSAXLE
INDEX
page page
GENERAL INFORMATION
31TH TRANSAXLE........................ 2
FLUID LEVEL AND CONDITION.............. 2
SELECTION OF LUBRICANT................ 3
SPECIAL ADDITIVES...................... 3
DESCRIPTION AND OPERATION
CLUTCHES, BAND SERVOS, AND
ACCUMULATOR
...................... 3
FLOW CONTROL VALVES.................. 3
GEARSHIFT AND PARKING LOCK CONTROLS . . 4
GOVERNOR............................. 4
HYDRAULIC CONTROL SYSTEM............. 3
PRESSURE REGULATING VALVES........... 3
PRESSURE SUPPLY SYSTEM............... 3
TORQUE CONVERTER CLUTCH SOLENOID
WIRING CONNECTOR................... 4
TORQUE CONVERTER CLUTCH............. 3
DIAGNOSIS AND TESTING
CLUTCH AND SERVO AIR PRESSURE TESTS . 15
FLUID LEAKAGE-TRANSAXLE TORQUE
CONVERTER HOUSING AREA............ 15
HYDRAULIC PRESSURE TESTS............ 13
ROAD TEST............................. 4
THREE SPEED TRANSAXLE DIAGNOSIS AND
TESTS............................... 4
SERVICE PROCEDURES
ALUMINUM THREAD REPAIR.............. 18
FLUID AND FILTER CHANGE............... 16
FLUID DRAIN AND REFILL................. 18
FLUSHING COOLERS AND TUBES.......... 18
OIL PUMP VOLUME CHECK............... 19
REMOVAL AND INSTALLATION
FRONT PUMP OIL SEAL.................. 21
PARK/NEUTRAL STARTING AND BACK-UP
LAMP SWITCH........................ 19
TRANSAXLE AND TORQUE CONVERTER
REMOVAL............................ 20
VEHICLE SPEED SENSOR PINION GEAR..... 19DISASSEMBLY AND ASSEMBLY
ACCUMULATOR-RECONDITION............ 36
DIFFERENTIAL REPAIR................... 46
FRONT CLUTCH-RECONDITION............ 32
FRONT PLANETARY & ANNULUS GEAR-
RECONDITION........................ 35
KICKDOWN SERVO (CONTROLLED LOAD)-
RECONDITION........................ 37
LOW/REVERSE (REAR)
SERVO-RECONDITION.................. 36
OIL PUMP-RECONDITION................. 31
OUTPUT SHAFT REPAIR.................. 43
PARKING PAWL......................... 42
REAR CLUTCH-RECONDITION............. 33
TRANSAXLE........................... 21
TRANSFER SHAFT REPAIR................ 38
VALVE BODY RECONDITION............... 27
CLEANING AND INSPECTION
VALVE BODY........................... 50
ADJUSTMENTS
BAND ADJUSTMENT..................... 51
BEARING ADJUSTMENT PROCEDURES...... 52
DIFFERENTIAL BEARING................. 53
GEARSHIFT CABLE ADJUSTMENT.......... 51
HYDRAULIC CONTROL PRESSURE
ADJUSTMENTS....................... 52
OUTPUT SHAFT BEARING................ 52
THROTTLE PRESSURE LINKAGE
ADJUSTMENT......................... 51
TRANSFER SHAFT BEARING.............. 54
SCHEMATICS AND DIAGRAMS
31TH TRANSAXLE HYDRAULIC SCHEMATIC . . 56
SPECIFICATIONS
31TH AUTOMATIC TRANSAXLE............. 64
31TH TORQUE SPECIFICATIONS........... 65
SPECIAL TOOLS
31TH AUTOMATIC TRANSAXLE............. 66
NSTRANSAXLE AND POWER TRANSFER UNIT 21 - 1
Page 1476 of 1938

GENERAL INFORMATION
31TH TRANSAXLE
NOTE: Safety goggles should be worn at all times
when working on these transaxles.
This transaxle combines torque converter, three
speed transmission, final drive gearing, and differen-
tial into a front wheel drive system. The identifica-
tion markings and usage of the transaxle are charted
in Diagnosis and Tests.
NOTE: Transaxle operation requirements are differ-
ent for each vehicle and engine combination. Some
internal parts will be different to provide for this.
Therefore, when replacing parts, refer to the seven
digit part number stamped on rear of the transaxle
oil pan flange.
Within this transaxle, there are three primary
areas:
(1) Main center line plus valve body.
(2) Transfer shaft center line (includes governor
and parking sprag).
(3) Differential center line.
(4) Center distances between the main rotating
parts in these three areas are held precise to main-
tain a low noise level.
(5) The torque converter, transaxle area, and dif-
ferential are housed in an integral aluminum die
casting.The differential oil sump is common
with the transaxle sump. Separate filling of the
differential is NOT necessary.
(6) The torque converter is attached to the crank-
shaft through a flexible driving plate. Cooling of the
converter is accomplished by circulating the tran-
saxle fluid through a remote cooler. There are two
types of coolers used. An oil-to-water type cooler
located in the radiator side tank and/or an oil-to air
heat exchanger. The torque converter assembly is a
sealed unit that cannot be disassembled.
(7) The transaxle fluid is filtered by an internal fil-
ter attached to the lower side of the valve body
assembly.
(8) Engine torque is transmitted to the torque con-
verter then, through the input shaft to multiple-disc
clutches in the transaxle. The power flow depends on
the application of the clutches and bands. Refer to
Elements in Use Chart in Diagnosis and Tests sec-
tion.
(9) The transaxle consists of:
²Two multiple-disc clutches
²An overrunning clutch
²Two servos
²A hydraulic accumulator
²Two bands²Two planetary gear sets
This provides three forward ratios and a reverse
ratio. The common sun gear of the planetary gear
sets is connected to the front clutch by a driving
shell. The drive shell is splined to the sun gear and
front clutch retainer. The hydraulic system consists
of an oil pump, and a single valve body which con-
tains all of the valves except the governor valves.
The transaxle sump and differential sump are both
vented through the dipstick. Output torque from the
main center line is delivered through helical gears to
the transfer shaft. This gear set is a factor of the
final drive (axle) ratio. The shaft also carries the gov-
ernor and parking sprag. An integral helical gear on
the transfer shaft drives the differential ring gear.
The final drive gearing is completed with one of two
gear ratios of 2.98 or 3.19 depending on model and
application.
FLUID LEVEL AND CONDITION
NOTE: The transmission and differential sump have
a common oil sump with a communicating 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 be sure that the fluid level check is accurate.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 sta-
bilization between differential and transmis-
sion.The fluid should be at normal operating
temperature (approximately 82 C. or 180 F.). The
fluid level is correct if it is in the HOT region (cross-
hatched area) on the dipstick.
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 servo operation.
Foaming can also result in fluid escaping from the
transaxle dipstick 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.
21 - 2 TRANSAXLE AND POWER TRANSFER UNITNS
Page 1477 of 1938

If there is any doubt about its condition, drain out a
sample for a double check.
SELECTION OF LUBRICANT
It is important that the proper lubricant be used in
these transmissions. Mopar ATF PLUS 3 (Automatic
Transmission Fluid- type 7176) should be used to aid
in ensuring optimum transmission performance. 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
addition of any fluids to the transmission, other than
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
TORQUE CONVERTER CLUTCH
A torque converter clutch is standard on all vehi-
cles. The torque converter clutch is activated only in
direct drive and is controlled by the engine electron-
ics. A solenoid on the valve body, is powered by the
powertrain control module to activate torque con-
verter clutch.
HYDRAULIC CONTROL SYSTEM
The hydraulic control system makes the transaxle
fully automatic, and has four important functions to
perform. The components of any automatic control
system may be grouped into the following basic
groups:
The pressure supply system, the pressure regulat-
ing valves, the flow control valves, the clutches, and
band servos.
Taking each of these basic groups or systems in
turn, the control system may be described as follows:
PRESSURE SUPPLY SYSTEM
The pressure supply system consists of an oil pump
driven by the engine through the torque converter.
The single pump furnishes pressure for all the
hydraulic and lubrication requirements.Oil pump
housing assemblies are available with prese-
lected pump gears.
PRESSURE REGULATING VALVES
The pressure regulating valve controls line pres-
sure dependent on throttle opening. The governor
valve transmits regulated pressure to the valve body
(in conjunction with vehicle speed) to control upshift
and downshift.The throttle valve transmits regulated pressure to
the transaxle (dependent on throttle position) to con-
trol upshift and downshift.
FLOW CONTROL VALVES
The manual valve provides the different transaxle
drive ranges as selected by the vehicle operator.
The 1-2 shift valve automatically shifts the tran-
saxle from first to second or from second to first,
depending on the vehicle operation.
The 2-3 shift valve automatically shifts the tran-
saxle from second to third or from third to second
depending on the vehicle operation.
The kickdown valve makes possible a forced down-
shift from third to second, second to first, or third to
first (depending on vehicle speed). This can be done
by depressing the accelerator pedal past the detent
feel near wide open throttle.
The shuttle valve has two separate functions and
performs each independently of the other. The first is
providing fast release of the kickdown band, and
smooth front clutch engagement when a lift-foot
upshift from second to third is made. The second
function is to regulate the application of the kick-
down servo and band when making third to second
kickdown.
The by-pass valve provides for smooth application
of the kickdown band on 1-2 upshifts.
The torque converter clutch solenoid allows for the
electronic control of the torque converter clutch. It
also disengages the torque converter at closed throt-
tle. This is done during engine warm-up, and part-
throttle acceleration.
The switch valve directs oil to apply the torque
converter clutch in one position. The switch valve
releases the torque converter clutch in the other posi-
tion.
CLUTCHES, BAND SERVOS, AND ACCUMULATOR
The front and rear clutch pistons, and both servo
pistons are moved hydraulically to engage the
clutches and apply the bands. The pistons are
released by spring tension when hydraulic pressure
is released. On the 2-3 upshift, the kickdown servo
piston is released by spring tension and hydraulic
pressure.
The accumulator controls the hydraulic pressure
on the apply side of the kickdown servo during the
1-2 upshift; thereby, cushioning the kickdown band
application at any throttle position.
NSTRANSAXLE AND POWER TRANSFER UNIT 21 - 3
GENERAL INFORMATION (Continued)
Page 1478 of 1938

GEARSHIFT AND PARKING LOCK CONTROLS
The transaxle is controlled by a lever type gear-
shift incorporated within the steering column. The
control has six selector lever positions: P (park), R
(reverse), N (neutral), and D (drive), 2 (second), and
1 (first). The parking lock is applied by moving the
selector lever past a gate to the P position.Do not
apply the parking lock until the vehicle has
stopped; otherwise, a severe ratchet noise will
occur.
TORQUE CONVERTER CLUTCH SOLENOID WIRING
CONNECTOR
If wiring connector is unplugged, the torque con-
verter will not engage (Fig. 1) .
GOVERNOR
The governor may be serviced by removing the
transaxle oil pan and valve body assembly. The gov-
ernor may be unbolted from the governor support
and removed from the transaxle for reconditioning or
replacement.
When cleaning or assembling the governor, make
sure the governor valves move freely in the bores of
the governor body.
DIAGNOSIS AND TESTING
THREE SPEED TRANSAXLE DIAGNOSIS AND
TESTS
Automatic transaxle malfunctions may be caused
by four general conditions:
(1) Poor engine performance
(2) Improper adjustments
(3) Hydraulic malfunctions
(4) Mechanical malfunctionsDiagnosis of these problems should always begin
by checking the easily accessible variables; fluid level
and condition, gearshift cable adjustment, and throt-
tle pressure 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 tests should be per-
formed
31TH HYDRAULIC TROUBLE CODE CHARTS
The following charts should be used to help diag-
nose hydraulic or mechanical faults in the transaxle .
ROAD TEST
Prior to performing a road test, check the fluid
level, and control cable adjustments.
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 at high speeds, but has poor
acceleration, the converter's overrunning clutch may
be slipping. If acceleration is normal, but high throt-
tle opening is needed for high speeds, the stator
clutch may have seized.
Observe closely for slipping or engine speed flare-
up. Slipping or flare-up in any gear usually indicates
clutch, band, or overrunning clutch problems. If the
condition is far advanced, an overhaul will probably
be necessary to restore normal operation.
In most cases, the clutch or band that is slipping
can be determined by noting the transaxle operation
in all selector positions. Then comparing which inter-
nal units are applied in those positions. The Ele-
ments in Use Chart provides a basis for road test
analysis .
The rear clutch is applied in both the D first gear
and 1 first gear positions. Also the overrunning
clutch is applied in D first gear and the low/reverse
band is applied in 1 first gear position. If the tran-
saxle slips in D range first gear, but does not slip in
1 first gear, the overrunning clutch is slipping. Simi-
larly, if the transaxle slips in any two forward gears,
the rear clutch is slipping.
Using the same procedure, the rear clutch and
front clutch are applied in D third gear. If the tran-
saxle slips in third gear, either the front clutch or the
rear clutch is slipping. By selecting another gear
which does not use one of those units, the unit which
is slipping can be determined. If the transaxle also
slips in reverse, the front clutch is slipping. If the
transaxle does not slip in reverse, the rear clutch is
slipping.
The process of eliminating can be used to detect
any unit which slips and to confirm proper operation
of good units. Road testing can usually diagnose slip-
ping units. Although the actual cause of the problem
Fig. 1 Torque Converter Clutch Solenoid Wiring
Connector
21 - 4 TRANSAXLE AND POWER TRANSFER UNITNS
DESCRIPTION AND OPERATION (Continued)
Page 1479 of 1938
Diagnosis Guide
NSTRANSAXLE AND POWER TRANSFER UNIT 21 - 5
DIAGNOSIS AND TESTING (Continued)
Page 1480 of 1938
Diagnosis Guide
21 - 6 TRANSAXLE AND POWER TRANSFER UNITNS
DIAGNOSIS AND TESTING (Continued)