(40) Install oil filter and gasket into position (Fig.
93).
(41) Install oil filter-to-valve body screws (Fig. 94)
and torque to 5 N´m (45 in. lbs.) torque.(42) Install an 1/8º bead of MopartSilicone Rub-
ber Adhesive Sealant to the transaxle oil pan (Fig.
95). Install oil pan to case and immediately install
and torque oil pan-to-case bolts (Fig. 96) to 19 N´m
(165 in. lbs.) torque.
Fig. 93 Oil Filter and Gasket
1 - OIL FILTER
2 - GASKET
3 - VALVE BODY
Fig. 94 Oil Filter Screws
1 - SCREWDRIVER HANDLE
2 - SPECIAL TOOL L-4553
3 - OIL FILTER SCREWS (2)
4 - OIL FILTER
Fig. 95 Transaxle Oil Pan
1 - TRANSAXLE OIL PAN
2 - OIL FILTER
Fig. 96 Transaxle Oil Pan Bolts
1 - TRANSAXLE OIL PAN
2 - OIL PAN BOLTS
21 - 60 31TH AUTOMATIC TRANSAXLERS
31TH AUTOMATIC TRANSAXLE (Continued)
ProCarManuals.com
TORQUE SPECIFICATIONS
Description N´m Ft. Lbs. In. Lbs.
Bolt, Differential Bearing Retainer-to-Case 34 Ð 300
Bolt, Differential Cover-to-Case 19 Ð 165
Bolt, Differential Ring Gear-to-Case 95 70 Ð
Bolt, Extension Housing-to-Case 28 Ð 250
Bolt, Drive Plate-to-Crankshaft 95 70 Ð
Bolt, Drive Plate-to-Torque Converter 68 50 Ð
Bolt, Governor-to-Support 7 Ð 60
Bolt, Output Gear Strap 23 17 Ð
Bolt, Oil Pan-to-Case 19 Ð 165
Bolt, Oil Pump-to-Case 31 Ð 275
Bolt, Park Rod Support-to-Case 28 Ð 250
Bolt, Reaction Support-to-Pump Body 28 Ð 250
Bolt, Sprag Retainer-to-Case 28 Ð 250
Bolt, Starter Motor-to-Transaxle 54 40 Ð
Bolt, Transaxle Case-to-Engine Block 95 70 Ð
Bolt, Transfer Gear Cover-to-Case 19 Ð 165
Bolt, Transfer Gear Strap 23 17 Ð
Bolt, Valve Body-to-Case 12 Ð 105
Fitting, Transaxle Oil Cooler-to-Case 7 Ð 60
Screw, Fluid Filter 5 Ð 45
Screw, Cooler Bypass Valve-to-Transfer Plate 5 Ð 40
Screw, Governor Counterweight 28 Ð 250
Screw, Manual Valve Lever-to-Shaft 12 Ð 105
Screw, Speedo Adapter-to-Extension Housing 7 Ð 60
Screw, Valve Body-to-Transfer Plate 5 Ð 45
Nut, Kickdown Band Adjuster Lock 47 35 Ð
Nut, Output Gear-to-Shaft 271 200 Ð
Nut, Reverse Band Adjuster Lock 14 Ð 125
Nut, Transfer Gear-to-Shaft 271 200 Ð
Plug, Pressure Tap 5 Ð 45
Plug, Rear Band Lever Pivot Shaft 7 Ð 60
Switch, Park/Neutral 34 25 Ð
21 - 74 31TH AUTOMATIC TRANSAXLERS
31TH AUTOMATIC TRANSAXLE (Continued)
ProCarManuals.com
(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
1¤2turns.
(6) Hold adjusting screw in place and tighten lock-
nut to 14 N´m (125 ft. lbs.) torque.
(7) Install a bead of MopartSilicone 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
MopartATF Plus 4, Type 9602, fluid.
Fig. 110 Front (Kickdown) Band Adjustment
Location
1 - KICKDOWN BAND ADJUSTING SCREW
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)
RS31TH AUTOMATIC TRANSAXLE21-81
BANDS (Continued)
ProCarManuals.com
FLUID
STANDARD PROCEDURE
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 thetransaxle dipstick where it may be mistaken for a
leak.
FLUID CONDITION
Along with fluid level, it is important to check the
condition of the fluid. MopartATF+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.
ATF+4 also has a unique odor that may change with
age. Consequently,odor and color cannot be used
to indicate the fluid condition, or the need for a
fluid change.
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 MoparTATF+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.
(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 MopartSilicone Rubber Adhesive Sealant.
Torque oil pan bolts to 19 N´m (165 in. lbs.).
(7) Pour four quarts of MopartATF+4 (Automatic
Transmission Fluid-Type 9602) through the dipstick
opening.
Fig. 165 Fluid Level Indicator Markings
1 - TRANSAXLE DIPSTICK
RS31TH AUTOMATIC TRANSAXLE21-99
ProCarManuals.com
(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 MopartATF+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
applied, move selector lever momentarily to each
position, ending in the park or neutral position.
(8) 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).
(9) Recheck the fluid level after the transaxle has
reached normal operating temperature (180ÉF.).
(Refer to 21 - TRANSMISSION/TRANSAXLE/AUTO-
MATIC - 31TH/FLUID - STANDARD PROCEDURE)
(10) To prevent dirt from entering transaxle, make
certain that dipstick is fully seated into the dipstick
opening.
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
21 - 100 31TH AUTOMATIC TRANSAXLERS
FLUID (Continued)
ProCarManuals.com
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 compressed
air. 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 drawsfluid 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.
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 MopartATF +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-
Fig. 182 Oil Pump Assembly
1 - REACTION SHAFT SUPPORT
2 - INNER GEAR
3 - PUMP BODY4 - PUMP BUSHING
5 - OUTER GEAR
RS31TH AUTOMATIC TRANSAXLE21 - 105
GOVERNOR (Continued)
ProCarManuals.com
VALVE BODY
REMOVAL
(1) Disconnect battery negative cable.
(2) Disconnect throttle valve cable from throttle
valve lever at transaxle.
(3) Disconnect gearshift cable from gearshift lever
at transaxle.
(4) Disconnect torque converter clutch solenoid
connector.
(5) Raise vehicle on hoist.
(6) Remove transaxle oil pan bolts (Fig. 297).
(7) Separate oil pan from case and drain fluid into
suitable container (Fig. 298).(8) Remove oil filter-to-valve body screws (Fig.
299).
(9) Remove oil filter and gasket (Fig. 300).
Fig. 297 Transaxle Oil Pan Bolts
1 - TRANSAXLE OIL PAN
2 - OIL PAN BOLTS
Fig. 298 Transaxle Oil Pan
1 - TRANSAXLE OIL PAN
2 - OIL FILTER
Fig. 299 Oil Filter Screws
1 - SCREWDRIVER HANDLE
2 - SPECIAL TOOL L-4553
3 - OIL FILTER SCREWS (2)
4 - OIL FILTER
Fig. 300 Oil Filter and Gasket
1 - OIL FILTER
2 - GASKET
3 - VALVE BODY
21 - 146 31TH AUTOMATIC TRANSAXLERS
ProCarManuals.com
(5) Install oil filter and gasket (Fig. 336).(6) Install oil filter-to-valve body screws (Fig. 337)
to 5 N´m (45 in. lbs.).
(7) Install a bead of MopartSilicone Rubber Adhe-
sive Sealant to oil pan (Fig. 338) and immediately
install to case.
Fig. 335 Parking Rod
1 - VALVE BODY
2 - PARKING ROD
Fig. 336 Oil Filter and Gasket
1 - OIL FILTER
2 - GASKET
3 - VALVE BODY
Fig. 337 Oil Filter Screws
1 - SCREWDRIVER HANDLE
2 - SPECIAL TOOL L-4553
3 - OIL FILTER SCREWS (2)
4 - OIL FILTER
Fig. 338 Transaxle Oil Pan
1 - TRANSAXLE OIL PAN
2 - OIL FILTER
RS31TH AUTOMATIC TRANSAXLE21 - 159
VALVE BODY (Continued)
ProCarManuals.com