2001 DODGE TOWN AND COUNTRY oil type

(transmission fluid) this indicates that the Transmis-
sion differential carrier seal should be replaced. If
the fluid leaking is light brown (gear lube) this indi-
cates that the Power Transfer Unit input seal should
be replaced. For replacement of these seals refer to
Power Transfer Unit Service Procedures.
If fluid is leaking from weep hole B (Fig. 5) the
type of fluid leaking will determine which seal is
leaking. If the fluid leaking is red in color (transmis-
sion fluid) this indicates that the input shaft end seal
should be replaced. If the fluid leaking is light brown
(gear lube) this indicates that the half shaft innerseal and P.T.U. input shaft cover seal should be
replaced. For replacement of these seals refer to
Power Transfer Unit Service Procedures.
Before condemning any seal or gasket be sure that
the rear rocker arm cover on the engine is not the
cause of the oil leak. Oil leaking from the rocker arm
cover is easily mistaken for a leaking Power Transfer
Unit.
STANDARD PROCEDURE - FLUID LEVEL
INSPECTION
(1) Raise vehicle on hoist.
(2) Remove PTU inspection plug (Fig. 6).
(3) Fluid level should be within 3/16º from bottom
of inspection hole. Add Moparž Gear and Axle Lubri-
cant 80W-90 as necessary with suitable suction gun
(Fig. 7).
(4) Install inspection plug and torque to 20 N´m
(180 in. lbs.) torque.
(5) Lower vehicle.
STANDARD PROCEDURE - PTU FLUID CHANGE
NOTE: PTU Fluid should be changed upon servic-
ing the unit, or at the unit's regular scheduled inter-
val. (Refer to LUBRICATION & MAINTENANCE/
MAINTENANCE SCHEDULES - DESCRIPTION)
(1) Raise vehicle on hoist.
(2) Remove PTU inspection plug (Fig. 8).
Fig. 3 Seal Location
1 - INPUT SHAFT
2 - OUTPUT SHAFT
3 - REAR COVER
4 - P.T.U. CASE
5 - INPUT SHAFT SEAL
Fig. 4 Seal Location
1 - P.T.U. INPUT SHAFT COVER SEAL
2 - HALF SHAFT INNER SEAL
3 - INSIDE VIEW OF P.T.U. END COVER
Fig. 5 Weep Hole Locations
1 - ENGINE OIL PAN
2 - WEEP HOLE ªAº
3 - TRANSAXLE CASE
4 - P.T.U.
5 - WEEP HOLE ªBº
21 - 4 POWER TRANSFER UNITRS
POWER TRANSFER UNIT (Continued)
ProCarManuals.com

REMOVAL.............................118
INSTALLATION..........................118
THROTTLE VALVE CABLE
REMOVAL.............................118
INSTALLATION..........................118
ADJUSTMENTS.........................120
TORQUE CONVERTER
DESCRIPTION..........................120
OPERATION............................123
REMOVAL.............................125
INSTALLATION..........................125
TRANSFER SYSTEM - OUTPUT SHAFT/GEAR/
BEARING
REMOVAL.............................126
INSTALLATION..........................129
ADJUSTMENTS.........................132TRANSFER SYSTEM - TRANSFER SHAFT/
GEAR/BEARING
REMOVAL.............................134
INSTALLATION..........................137
ADJUSTMENTS.........................142
VALVE BODY
REMOVAL.............................142
DISASSEMBLY..........................145
CLEANING.............................151
INSPECTION...........................152
ASSEMBLY............................152
INSTALLATION..........................155
ADJUSTMENTS.........................157
VEHICLE SPEED SENSOR/PINION GEAR
REMOVAL.............................157
INSTALLATION..........................157
AUTOMATIC - 31TH
DESCRIPTION
This transaxle combines torque converter, three
speed transmission, final drive gearing, and differen-
tial into a front wheel drive system.
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.
Center distances between the main rotating parts
in these three areas are held precise to maintain a
low noise level.
The torque converter, transaxle area, and differen-
tial are housed in an integral aluminum die casting.
The differential oil sump is common with the
transaxle sump. Separate filling of the differen-
tial is NOT necessary.
The torque converter is attached to the crankshaft
through a flexible driving plate. Cooling of the con-
verter is accomplished by circulating the transaxle
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.
The transaxle fluid is filtered by an internal filter
attached to the lower side of the valve body assembly.Engine torque is transmitted to the torque con-
verter and 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 section.
The transaxle consists of:
²Two multiple-disc clutches
²An overrunning clutch
²Two servos
²A hydraulic accumulator
²Two bands
²Two 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 driving 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 in the
transaxle final drive (axle) ratio. The shaft also car-
ries the governor and parking sprag. An integral heli-
cal gear on the transfer shaft drives the differential
ring gear.
21 - 22 AUTOMATIC - 31THRS
ProCarManuals.com

SPECIFICATIONS
31TH AUTOMATIC TRANSAXLE
GENERAL SPECIFICATIONS
Transaxle TypeThree speed automatic with torque converter and
integral differential
Cooling Method Air to oil heat exchanger
Lubrication Method Pump (internal-external gear-type)
GEAR RATIOS
1st Gear 2.69
2nd Gear 1.55
3rd Gear 1.00
Reverse Gear 2.10
BAND ADJUSTMENT
Kickdown (Front)ÐBacked Off From 8 N²m (72 in. lbs.) 2ò turns
Low-Reverse (Rear)ÐBacked Off From 5 N²m (41 in.
lbs.)3 Turns
BEARING SETTINGS (END PLAY & TURNING TORQUE)
Description Metric Standard
Differential Assembly 0.7-1.4 N´m 6-12 in. lbs.
Output Shaft 0-0.3 N´m 0-3 in. lbs.
Transfer Shaft 0.051-0.254 mm 0.002-0.010 in. (end play)
Overall Drag At Output Hub 0.03-1.8 N´m 3-16 in. lbs.
CLUTCH CLEARANCES
Description Metric Standard
Front Clutch (Not Adjustable) 1.27-2.79 mm 0.050-0.110 in.
Rear Clutch 0.71-1.10 mm 0.028-0.043 in.
END PLAY
Description Metric Standard
Input Shaft 0.19-1.50 mm 0.008-0.060 in.
Front Clutch Retainer 0.76-2.69 mm 0.030-0.106 in.
Front Carrier 0.89-1.45 mm 0.007-0.057 in.
Front Annulus Gear 0.09-0.50 mm 0.0035-0.020 in.
Planet Pinion 0.15-0.59 mm 0.006-0.023 in.
Reverse Drum 0.76-3.36 mm 0.030-0.132 in.
RSAUTOMATIC - 31TH21-71
AUTOMATIC - 31TH (Continued)
ProCarManuals.com

(5) Back off front band adjusting screw 2ò turns.
(6) Hold adjuster screw in position and tighten
locknut to 47 N´m (35 ft. lbs.) torque.
(7) Install air cleaner assembly.
(8) Connect battery negative cable.
ADJUSTMENTS - REAR BAND
The transmission oil pan must be removed for
access to the rear (low/reverse) band adjusting screw.
(1) Raise vehicle.
(2) Remove transaxle oil pan and drain fluid (Fig.
111) (Fig. 112).(3) Loosen band adjusting screw locknut 5-6 turns.
Be sure adjusting screw turns freely in lever.
(4) Tighten adjusting screw to 5 N´m (41 in. lbs.)
(Fig. 113).
(5) Back off adjusting screw 3 turns.
(6) Hold adjusting screw in place and tighten lock-
nut to 14 N´m (125 ft. lbs.) torque.
(7) Install a bead of Moparž Silicone Rubber Adhe-
sive Sealant to the oil pan and install to case imme-
diately.
(8) Install oil pan-to-case bolts and torque to 19
N´m (165 in. lbs.).
(9) Lower vehicle and refill transmission with
Moparž ATF Plus 4, Type 9602, fluid.
CLUTCH - FRONT
DESCRIPTION
The front clutch assembly (Fig. 119) is composed of
the front clutch retainer, pressure plate, clutch
plates, driving discs, piston, piston return spring,
return spring retainer, and snap-rings. The front
clutch is the forward-most component in the trans-
mission geartrain and is directly behind the oil
pump. It is considered a driving component.
NOTE: The number of discs and plates may vary
with each engine and vehicle combination.
Fig. 111 Transaxle Oil Pan Bolts
1 - TRANSAXLE OIL PAN
2 - OIL PAN BOLTS
Fig. 112 Transaxle Oil Pan
1 - TRANSAXLE OIL PAN
2 - OIL FILTER
Fig. 113 Adjust Low/Reverse Band
1 - LOW-REVERSE BAND LEVER
2 - ADJUSTING SCREW
3 - STRUT
4 - LOW-REVERSE BAND
5 - LOCK NUT
6 - LEVER (SHORT)
21 - 80 AUTOMATIC - 31THRS
BANDS (Continued)
ProCarManuals.com

FLUID
STANDARD PROCEDURE - FLUID LEVEL AND
CONDITION CHECK
NOTE: The transmission and differential sump have
a common oil sump with a communicating opening
between the two.
FLUID LEVEL CHECK
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 fluid level indicator (Fig. 165).
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.
If there is any doubt about its condition, drain out a
sample for a double check.
FLUID CONDITION
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 recondition 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.
Moparž ATF+4 (Automatic Transmission Fluid-
Type 9602) when new is red in color. The ATF is dyed
red so it can be identified from other fluids used in
the vehicle such as engine oil or antifreeze. The red
color is not permanent and is not an indicator of fluid
condition. As the vehicle is driven, the ATF will begin
to look darker in color and may eventually become
brown. This is normal. A dark brown/black fluid
accompanied with a burnt odor and/or deterioration
in shift quality may indicate fluid deterioration or
transmission component failure.
After the fluid has been checked, seat the dipstick
fully to seal out water and dirt.
STANDARD PROCEDURE - FLUID AND FILTER
CHANGE
NOTE: For the recommended maintenance (fluid/fil-
ter change) intervals for this transaxle, (Refer to
LUBRICATION & MAINTENANCE/MAINTENANCE
SCHEDULES - DESCRIPTION)
NOTE: Only fluids of the type labeled Moparž
ATF+4 (Automatic Transmission Fluid) Type 9602
should be used. A filter change should be made at
the time of the transmission oil change. The magnet
(on the inside of the oil pan) should also be cleaned
with a clean, dry cloth.
NOTE: If the transaxle is disassembled for any rea-
son, the fluid and filter should be changed.
FLUID/FILTER SERVICE (RECOMMENDED)
(1) Raise vehicle on a hoist. Place a drain con-
tainer with a large opening, under transaxle oil pan.
Fig. 165 Fluid Level Indicator Markings
1 - TRANSAXLE DIPSTICK
21 - 98 AUTOMATIC - 31THRS
ProCarManuals.com

(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) Remove oil filter-to-valve body screws (Fig.
166).
(4) Remove oil filter and gasket (Fig. 167).
(5) Install a new filter and gasket (Fig. 167).
(6) Clean the oil pan and magnet. Reinstall pan
using new Moparž Silicone Rubber Adhesive Sealant.
Torque oil pan bolts to 19 N´m (165 in. lbs.).(7) Pour four quarts of Moparž ATF+4 (Automatic
Transmission Fluid-Type 9602) through the dipstick
opening.
(8) 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.
(9) Check the transaxle fluid level and add an
appropriate amount to bring the transaxle fluid level
to 3mm (1/8 in.) below the ªADDº mark on the dip-
stick (Fig. 168).
(10) Recheck the fluid level after the transaxle has
reached normal operating temperature (180ÉF.).
(Refer to 21 - TRANSMISSION/TRANSAXLE/AUTO-
MATIC - 31TH/FLUID - STANDARD PROCEDURE)
(11) To prevent dirt from entering transaxle, make
certain that dipstick is fully seated into the dipstick
opening.
DIPSTICK TUBE FLUID SUCTION METHOD
(ALTERNATIVE)
(1) When performing the fluid suction method,
make sure the transaxle is at full operating temper-
ature.
(2) To perform the dipstick tube fluid suction
method, use a suitable fluid suction device (VaculaŸ
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) Pour four quarts of Moparž ATF+4 (Automatic
Transmission FluidÐType 9602) through the dipstick
opening.
(7) Start engine and allow to idle for at least one
minute. Then, with parking and service brakes
Fig. 166 Oil Filter Screws
1 - SCREWDRIVER HANDLE
2 - SPECIAL TOOL L-4553
3 - OIL FILTER SCREWS (2)
4 - OIL FILTER
Fig. 167 Oil Filter and Gasket
1 - OIL FILTER
2 - GASKET
3 - VALVE BODY
Fig. 168 Dipstick Markings
1 - TRANSAXLE DIPSTICK
RSAUTOMATIC - 31TH21-99
FLUID (Continued)
ProCarManuals.com

pressure. Generally governor pressure ranges from
0-100 psi from idle to maximum speed, and rises pro-
portionally with the increase in output shaft speed.
Governor pressure and throttle pressure are acting
upon the shift valves to determine when a shift will
occur. Governor pressure is a direct indication of road
speed, and throttle pressure is an indication of
engine load. When both parameters have been met
by the throttle and governor pressures, an upshift or
downshift will occur.
CLEANING
Thoroughly clean all the governor parts in a suit-
able cleaning solution but do not use any type of
caustic cleaning agents.
The governor weight components and the governor
valve, must slide freely in their bores when clean and
dry. Minor surface scratches and burrs can be
smoothed with crocus cloth.
INSPECTION
The aluminum governor valve and outer weight
have a hard coating on them. Check condition of this
coating carefully. Do not reuse either part if the coat-
ing is damaged.
Inspect the governor weight spring for distortion.
Replace the spring, if distorted, collapsed, or broken.
Clean the filter in solvent and dry it with compressedair. Replace the filter, if damaged. Inspect the park
gear for chipped or worn gear teeth or damaged ring
grooves. Replace the gear, if damaged.
Check the teeth on the park gear for wear or dam-
age. Replace the gear if necessary. Inspect the metal
seal rings on the park gear hub. Replace the rings
only if severely worn, or broken.
OIL PUMP
DESCRIPTION
The oil pump is located in the pump housing inside
the bell housing of the transmission case. The oil
pump consists of an inner and outer gear, a housing,
and a cover that also serves as the reaction shaft
support (Fig. 182).
OPERATION
As the torque converter rotates, the converter hub
rotates the inner and outer gears. As the gears
rotate, the clearance between the gear teeth
increases in the crescent area, and creates a suction
at the inlet side of the pump. This suction draws
fluid through the pump inlet from the oil pan. As the
clearance between the gear teeth in the crescent area
decreases, it forces pressurized fluid into the pump
outlet and to the valve body.
Fig. 182 Oil Pump Assembly
1 - REACTION SHAFT SUPPORT
2 - INNER GEAR
3 - PUMP BODY4 - PUMP BUSHING
5 - OUTER GEAR
21 - 104 AUTOMATIC - 31THRS
GOVERNOR (Continued)
ProCarManuals.com

STANDARD PROCEDURE - OIL PUMP VOLUME
CHECK
Measuring the oil pump output volume will deter-
mine if sufficient oil flow to the transmission oil
cooler exists, and whether or not an internal trans-
mission failure is present.
Verify that the transmission fluid is at the proper
level. Refer to the Fluid Level Check procedure in
this section. If necessary, fill the transmission to the
proper level with Moparž ATF +4, type 9602, Auto-
matic Transmission Fluid.
(1) Using hose cutters or a suitable blade, cut the
To coolerline off flush with the cooler inlet fitting
and place a collecting container under the open 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 one quart of transmission fluid is collected in
the container in 20 seconds or less, oil pump flow vol-
ume is within acceptable limits. If fluid flow is inter-
mittent, or it takes more than 20 seconds to collect
one quart of fluid, (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 31TH - DIAGNOSIS
AND TESTING) for further diagnosis.
(4) Re-connect theTo coolerline to the transmis-
sion cooler inlet using a service splice kit. Refer to
instructions included with the kit.
(5) Refill the transmission to proper level. (Refer
to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC
- 31TH/FLUID - STANDARD PROCEDURE)
DISASSEMBLY
(1) Remove reaction shaft support-to-pump body
bolts.
(2) Remove reaction shaft support, and the inner
and outer pump gears (Fig. 183).
CLEANING
Clean pump and support components with solvent
and dry them with compressed air.
INSPECTION
(1) Check condition of the seal rings and thrust
washer on the reaction shaft support. The seal rings
do not need to be replaced unless cracked, broken, or
severely worn.
(2) Visually inspect the pump and support compo-
nents. Replace the pump assembly if the seal ring
grooves or machined surfaces are worn, scored, pit-
ted, or damaged. Replace the pump assembly if the
gears if pitted, worn chipped, or damaged.
(3) Inspect the pump bushing. Then check the
reaction shaft support bushing. Replace the pump
assembly if either bushing is heavily worn, scored or
damaged.
(4) Clearance between outer gear and reaction
shaft housing should be 0.010 to 0.063 mm (0.0004 to
0.0025 in.). Clearance between inner gear and reac-
tion shaft housing should be 0.010 to 0.063 mm
(0.0004 to 0.0025 in.). Both clearances can be mea-
sured at the same time by installing the gears in the
pump body and measure pump component clearances
as follows:
(5) Reinstall gears to pump body and measure
outer gear-to-pocket clearance with a feeler gauge
(Fig. 184).Outer gear-to-pocket clearance should
be within 0.045-0.141 mm (0.0018-0.0056 in.).
(6) Measure both inner and outer gear side clear-
ance with PlastigageŸ. If PlastigageŸ is not avail-
able, measure across the pump body with a straight
edge and feeler gauge.
(a) Position an appropriate piece of PlastigageŸ
across both gears.
(b) Align the plastigage to a flat area on the
reaction shaft housing.
(c) Install the reaction shaft support to the
pump housing and torque to 28 N´m (250 in. lbs.).
(d) Separate the reaction shaft housing from the
pump housing and measure the PlastigageŸ fol-
lowing the instructions supplied with it.Inner
and outer gear side clearance should be
within 0.020-0.046 mm (0.0008-0.0018 in.).
ASSEMBLY
(1) Install inner and outer gears to pump body
(Fig. 183). Lubricate gears with Moparž ATF+4
(Automatic Transmission Fluid-Type 9602).
(2) Install reaction shaft support to pump body
and align holes.
(3) Install and torque reaction shaft support-to-
pump body bolts to 28 N´m (250 in. lbs.).
RSAUTOMATIC - 31TH21 - 105
OIL PUMP (Continued)
ProCarManuals.com