refill JEEP CHEROKEE 1995 Service Owner's Guide

nostic Procedures manual for diagnostic information
and operation of the DRB scan tool.
To test operation of the fan relay only, refer to Re-
laysÐOperation/Testing. This can be found in Group
14, Fuel Systems.
REMOVAL
The auxiliary cooling fan is attached to the radia-
tor upper crossmember behind the radiator.
(1) Remove the two fan mounting bolts from radi-
ator upper crossmember (Fig. 43).
(2) Disconnect the electric fan connector.
(3) Lift fan straight up and out of vehicle.
INSTALLATION
(1) Align lower retaining tabs of fan shroud with
slots in bracket at bottom of radiator. Push fan down
into position.
(2) Tighten the mounting bolts to 4 Nzm (31 in.
lbs.) torque.
(3) Connect auxiliary cooling fan electrical connec-
tor.
TRANSMISSION OIL COOLERS
WATER-TO-OIL COOLER
All models equipped with an automatic transmis-
sion are equipped with a transmission oil cooler
mounted internally within the radiator tank. This in-
ternal cooler is supplied as standard equipment on
all models equipped with an automatic transmission.
Transmission oil is cooled when it passes through
this separate cooler. In case of a leak in the internalradiator mounted transmission oil cooler, engine cool-
ant may become mixed with transmission fluid or
transmission fluid may enter engine cooling system.
Both cooling system and transmission should be
drained and inspected if the internal radiator
mounted transmission cooler is leaking.
Also refer to the section on Transmission Air-to-Oil
Coolers. This auxiliary air-to-oil cooler is an option
on most engine packages.
REPLACING WATER-TO-OIL COOLER IN
RADIATOR SIDE TANK
The internal transmission oil cooler located within
the radiator is not serviceable. If it requires service,
the radiator must be replaced.
Once the repaired or replacement radiator has
been installed, fill the cooling system and inspect for
leaks. Refer to the Refilling Cooling System and Test-
ing Cooling System For Leaks sections in this group.
If the transmission operates properly after repairing
the leak, drain the transmission and remove the
transmission oil pan. Inspect for sludge and/or rust.
Inspect for a dirty or plugged inlet filter. If none of
these conditions are found, the transmission and
torque convertor may not require reconditioning. Re-
fer to Group 21 for automatic transmission servicing.
AIR-TO-OIL COOLER
An auxiliary air-to-oil transmission oil cooler is
available with most engine packages.
On XJ and YJ models, the cooler is located in front
of the radiator or A/C condenser (if equipped) and be-
hind the grill (Figs. 44, 45 or 46). It is mounted to
the front frame crossmember.
Fig. 43 Auxiliary Cooling FanÐRemove/InstallÐ
Typical
Fig. 44 Auxiliary Air-To-Oil CoolerÐYJ Models
7 - 36 COOLING SYSTEM SERVICE PROCEDURESJ

(2) Remove fitting from pump housing (Fig. 10).
Prevent flow control valve and spring from
sliding out of housing bore.
(3) Remove and discard O-ring seal.
INSTALLATION
(1) If necessary, clean and install flow control valve
and spring in pump housing bore.Be sure the hex
nut end of the valve is facing in toward pump.
(2) Install O-ring seal onto fitting (Fig. 10).
(3) Install flow control valve in pump housing and
tighten to 75 Nzm (55 ft. lbs.) torque.
(4) Install pressure hose to valve.
POWER STEERING PUMPÐINITIAL OPERATION
CAUTION: The fluid level should be checked with
engine off to prevent injury from moving compo-
nents. Use only Mopar Power Steering Fluid. Do not
use automatic transmission fluid. Do not overfill.
Wipe filler cap clean, then check the fluid level.
The dipstick should indicate FULL COLD when the
fluid is at normal temperature 21ÉC to 27ÉC (70ÉF to
80ÉF).
(1) Fill the pump fluid reservoir to the proper level
and let the fluid settle for at least two (2) minutes.
(2) Start the engine and let run for a few seconds.
Then turn the engine off.
(3) Add fluid if necessary. Repeat the above proce-
dure until the fluid level remains constant after run-
ning the engine.
(4) Raise the front wheels off the ground.
(5) Start the engine. Slowly turn the steering
wheel right and left, lightly contacting the wheel
stops.
(6) Add power steering fluid if necessary.
(7) Lower the vehicle and turn the steering wheel
slowly from lock to lock.
(8) Stop the engine. Check the fluid level and refill
as required.
(9) If the fluid is extremely foamy, allow the vehi-
cle to stand a few minutes and repeat the above pro-
cedure.
Fig. 10 Flow Control Valve Fitting
JSTEERING 19 - 15

CONVERTER HOUSING LEAK DIAGNOSIS
Two items must be established when diagnosing
leaks from the converter housing area. First, it must
be verified that a leak condition actually exists. And
second, the true source of the leak must be deter-
mined.
Some suspected converter housing fluid leaks may
not be leaks at all. Residual fluid in the housing, or
excess fluid spilled during factory fill or refill after
repair can be mistaken for a leak. In addition, a rear
main seal leak can also be mistaken for a pump seal
leak if care is exercised.
Converter housing leaks have several potential
sources. Through careful observation, a leak source
can be identified before removing the transmission
for repair.
Pump seal leaks tend to move along the drive hub
and onto the rear of the converter. Pump O-ring or
pump body leaks follow the same path as a seal leak
(Fig. 9).
Pump vent or pump attaching bolt leaks are gener-
ally deposited on the inside of the converter housing
and not on the converter itself (Fig. 9).
Pump seal or gasket leaks usually travel down the
inside of the converter housing.
Front band lever pin plug leaks are generally de-
posited on the housing and not on the converter.
LEAK DIAGNOSIS PROCEDURE
(1) Raise the rear of the vehicle and allow accumu-
lated fluid to drain out of the converter housing.
(2) Check and adjust the transmission fluid level.
(3) Raise the vehicle. Remove the converter hous-
ing dust cover and wipe as much fluid as possible
from the converter housing.(4) Fabricate a test probe (Fig. 10). Then attach
the probe to the converter housing with one of the
dust shield bolts (Fig. 10).
(5) Have a helper run the engine at 2500 rpm
(with the transmission in Neutral) for two minutes;
then stop the engine.
(6) Inspect the test probe and converter housing. If
a leak is evident, note the color of the fluid. Trans-
mission fluid is red. Engine oil ranges in color from
brown to green, or to black when the oil is dirty.
(7) If the probe upper surface is dry, the converter
and seal are not at fault. A path of fluid across the
probe upper surface indicates a converter or seal
leak. Fluid leakingunderthe probe is coming from
the pump housing area (Fig. 11).
(8) Fluid leaking under the probe could be from
the: pump seal and/or bushing, pump vent, kickdown
lever shaft access plug, pump bolts, or porous spots
in the pump body or transmission case (Fig. 11).
(9) If porous spots in the transmission case or
pump body are the suspected leak source, pressurize
the transmission as described in Leak Testing With
Air Pressure.
Fig. 8 Air Pressure Test Passages
Fig. 9 Typical Converter Housing Leak Paths
Fig. 10 Leak Test Probe
J30RH/32RH TRANSMISSION DIAGNOSIS 21 - 75

30RH/32RH IN-VEHICLE SERVICE
INDEX
page page
Converter Drainback Check Valve Service...... 113
Fluid and Filter Replacement................. 99
Fluid Level Check......................... 99
Front Band Adjustment.................... 102
Governor and Park Gear Service............. 105
Oil Filter Replacement..................... 103
Park Interlock Cable Adjustment (XJ).......... 101
Park Lock Component Replacement.......... 108
Park/Neutral Position Switch Service.......... 109
Rear Band Adjustment.................... 103
Recommended Fluid....................... 99Refilling After Overhaul or Fluid/Filter Change . . . 100
Shift Cable Adjustment (XJ)................. 100
Shift Linkage Adjustment (YJ)............... 100
Speedometer Service..................... 109
Throttle Valve Cable Adjustment (XJ/YJ)....... 101
Transmission Cooler Flow Testing............ 113
Transmission Cooler Line and Fitting Service.... 111
Transmission Cooler Reverse Flushing......... 114
Valve Body Installation.................... 104
Valve Body Removal...................... 104
Valve Body Service....................... 104
RECOMMENDED FLUID
Recommended (and preferred) fluid for 30RH/32RH
transmissions is Mopar ATF Plus, type 7176.
Dexron II is not really recommended and should
only be used when ATF Plus is not available.
FLUID LEVEL CHECK
Transmission fluid level should be checked monthly
under normal operation. If the vehicle is used for
trailer towing or similar heavy load hauling, check
fluid level and condition weekly.
Fluid level is checked with the engine running at
curb idle speed, the transmission in Neutral and the
transmission fluid at normal operating temperature.
FLUID LEVEL CHECK PROCEDURE
(1) Transmission fluid must be at normal operating
temperature for accurate fluid level check. Drive ve-
hicle if necessary to bring fluid temperature up to
normal hot operating temperature of 82ÉC (180ÉF).
(2) Position vehicle on level surface. This is ex-
tremely important for accurate fluid level check.
(3) Start and run engine at curb idle speed.
(4) Apply parking brakes.
(5) Shift transmission momentarily into all gear
ranges. Then shift transmission back to Neutral.
(6) Clean top of filler tube and dipstick to keep dirt
from entering tube.
(7) Remove dipstick and check fluid level as fol-
lows:
(a) Dipstick has three fluid level indicator levels
(Fig. 1) which are a MIN dot, an OK crosshatch
area, and a MAX fill arrow.
(b) Correct maximum level is to MAX arrow
mark. Correct acceptable level is to OK mark in
crosshatch area.
(c) Incorrect level is at or below MIN dot.
(d) If fluid is low, add only enough Mopar ATF
Plus restore correct level. Do not overfill.CAUTION: Do not overfill the transmission. Overfill-
ing may cause leakage out the pump vent which
can be mistaken for a pump seal leak. Overfilling
will also cause fluid aeration and foaming as the ex-
cess fluid is picked up and churned by the gear
train. This will reduce fluid life significantly.
FLUID AND FILTER REPLACEMENT
NORMAL CHANGE INTERVAL
The fluid and filter should be changed (and the
bands adjusted) at recommended maintenance inter-
vals, or whenever the transmission has been disas-
sembled for any reason.
Refer to the Driveline section in Group O, Lubrica-
tion and Maintenance for recommended change inter-
vals. Refer to the fluid/filter replacement and band
adjustment procedures in this section.
SEVERE USAGE CHANGE INTERVAL
Under severe usage, the fluid and filter should be
changed and the bands adjusted at 12,000 mile (19
000 Km) intervals.
Severe usage is defined as:
(a) More than half of vehicle operation occurs in
heavy city traffic during hot weather (above 90É F).
(b) Vehicle is used for taxi, police, limousine, or
similar commercial operation.
Fig. 1 Fluid Level Marks On Transmission Dipstick
J30RH/32RH IN-VEHICLE SERVICE 21 - 99

(c) Vehicle is used for trailer towing or heavy
load hauling.
FLUID/FILTER REPLACEMENT PROCEDURE
(1) Raise vehicle.
(2) Remove oil pan and drain fluid.
(3) Clean oil pan and pan magnet. Then clean re-
maining gasket material from gasket surface of
transmission case.
(4) Remove fluid filter screws and remove filter.
(5) Position new filter on valve body and install fil-
ter screws. Tighten screws to 4 Nzm (35 in. lbs.)
torque.
(6) Adjust rear band at this time if required.
(7) Position new gasket on oil pan and install pan
on transmission. Tighten pan bolts to 150 in. lbs. (17
Nzm) torque.
(8) Adjust front band at this time if required.
(9) Lower vehicle and refill transmission with Mo-
par ATF Plus, type 7176 fluid.
REFILLING AFTER OVERHAUL OR FLUID/FILTER
CHANGE
The most effective way to avoid overfilling after a
fluid change or overhaul is as follows:
(1) Remove dipstick and insert clean funnel in
transmission fill tube.
(2) Add following initial quantity of Mopar ATF
Plus to transmission:
(a) If only fluid and filter were changed, add3
pints (1-1/2 quarts)of ATF Plus to transmission.
(b) If transmission was completely overhauled
and torque converter was replaced or drained, add
10 pints (5 quarts)of ATF Plus to transmission.
(3) Apply parking brakes.
(4) Start and run engine at normal curb idle speed.
(5) Apply service brakes, shift transmission
through all gear ranges then back to Neutral, and
leave engine running at curb idle speed.
(6) Remove funnel, insert dipstick and check fluid
level. Add only enough fluid to bring level toMIN
dot mark on dipstick.
(7) Drive vehicle until transmission fluid is at nor-
mal operating temperature. Then recheck fluid level
as described in next step.
(8) Leave engine running at curb idle speed, shift
into Neutral, and check fluid level again. This time,
add just enough fluid to bring level up toMAX ar-
row mark but do not overfill.
(9) When fluid level is correct, shut engine off, re-
lease park brake, remove funnel, and reseat dipstick
in fill tube.
SHIFT LINKAGE ADJUSTMENT (YJ)
(1) Check linkage adjustment by starting engine in
Park and Neutral.(2) Adjustment is OK if engine starts only in park
and Neutral. Adjustment is incorrect if engine starts
in one but not both positions.
(3) If engine starts in any position other than Park
or Neutral, or if engine will not start at all, park/
neutral position switch may be faulty.
(4) Shift transmission into Park.
(5) Raise vehicle.
(6) Check condition of shift rods, bellcrank,
bellcrank brackets and linkage bushings/grommets
(Fig. 2). Tighten, repair, replace worn, damaged
parts. Do not attempt adjustment if linkage compo-
nents are worn or damaged.
(7) Loosen shift rod trunnion lock bolt or nut. Be
sure upper shift rod slides freely in trunnion (Fig. 2).
Also be sure shift rods and bellcrank rotate freely
and do not bind at any point.
(8) Verify that manual lever is in Park detent (Fig.
2). Move lever all the way rearward to be sure it is in
Park.
(9) Check for positive engagement of park lock by
attempting to rotate propeller shaft. Shaft will not
turn when park pawl is engaged.
(10) Adjust shift rod trunnion to a obtain free pin
fit in bellcrank arm and tighten trunnion lock bolt or
nut. Prevent shift rod from turning while tightening
bolt or nut. Gearshift linkage lash must be elimi-
nated to obtain proper adjustment. Eliminate lash by
pulling downward on shift rod and pressing upward
on bellcrank.
(11) Confirm proper adjustment by starting engine
in Park and Neutral. Engine should start in these
positions only.If engine starts in any position
other than Park or Neutral, adjustment is in-
correct or neutral switch is faulty.
(12) Lower vehicle and verify that steering lock op-
erates correctly.
SHIFT CABLE ADJUSTMENT (XJ)
(1) Shift transmission into Park.
(2) Raise vehicle.
(3) Release cable adjuster clamp to unlock cable
(Figs. 3 and 4). Clamp is at transmission end of ca-
ble.
(4) Unsnap cable from transmission cable bracket.
(5) Move transmission shift lever fully rearward to
Park detent. Lever is on manual valve shaft at driver
side of case.
(6) Verify positive engagement of park lock by at-
tempting to rotate propeller shaft. Shaft will not ro-
tate when park lock is engaged.
(7) Snap cable into cable bracket.
(8) Lock shift cable by pressing cable adjuster
clamp down until it snaps into place.
(9) Check engine starting. Engine should start only
in Park and Neutral.
(10) Lower vehicle.
21 - 100 30RH/32RH IN-VEHICLE SERVICEJ

(3) Clean adjusting screw threads with Mopar rust
penetrant if necessary. Then lubricate threads with
Mopar spray lube or petroleum jelly. Be sure screw
turns freely in case. This is necessary for accurate
adjustment.
(4) Tighten band adjusting screw to 8 Nzm (72 in.
lbs.) torque with inch-pound torque wrench.If
Adapter Extension C-3705 is needed in order to
reach adjusting screw, tighten screw to only 5-6
Nzm (47-50 in. lbs.) torque (Fig. 8).
(5) Back off front band adjusting screw as follows:
²On 30RH (2.5L), back adjusting screw off 2-1/2
turns
²On 32RH (4.0L), back adjusting screw off 2-1/4
turns
(6) Hold adjuster screw in position and tighten
locknut to 41 Nzm (30 ft. lbs.) torque.
(7) Lower vehicle.
REAR BAND ADJUSTMENT
The transmission oil pan must be removed for ac-
cess to the rear (low-reverse) band adjusting screw.
(1) Raise vehicle.(2) Remove transmission oil pan and drain fluid.
(3) Loosen band adjusting screw locknut 5-6 turns.
Be sure adjusting screw turns freely in lever.
(4) Tighten adjusting screw as follows: On 32Rh
transmission, tighten screw to 8 Nzm (72 in. lbs.)
torque. On 30RH transmission, tighten adjusting
screw to 5 Nzm (41 in. lbs.) torque (Fig. 9).
(5) Back off rear band adjusting screw as follows:
²On 30RH (2.5L), back adjusting screw off 7 turns
²On 32RH (4.0L), back adjusting screw off 4 turns
(6) Hold adjusting screw in place and tighten lock-
nut to 34 Nzm (25 ft. lbs.) torque.
(7) Position new gasket on oil pan and install pan
on transmission. Tighten pan bolts to 17 Nzm (150 in.
lbs.) torque.
(8) Lower vehicle and refill transmission with rec-
ommended fluid.
OIL FILTER REPLACEMENT
(1) Raise vehicle.
(2) Remove oil pan and drain fluid.
(3) Remove filter screws and remove oil filter (Fig.
10).
(4) Position new filter on valve body and install fil-
ter screws finger tight.
(5) Tighten filter screws to 4 Nzm (35 in. lbs.) with
inch-pound torque wrench.
(6) Position new gasket on oil pan and install pan
Fig. 7 Throttle Valve Cable Adjustment
Fig. 8 Front Band Adjustment
Fig. 9 Rear Band Lever And Adjusting Screw
Location
J30RH/32RH IN-VEHICLE SERVICE 21 - 103

on transmission. Tighten pan bolts to 17 Nzm (150 in.
lbs.) torque.
(7) Lower vehicle.
(8) Refill transmission with Mopar ATF Plus.
VALVE BODY REMOVAL
(1) Raise vehicle.
(2) Remove oil pan and drain fluid.
(3) Disconnect gearshift and throttle linkage at
transmission levers.
(4) Loosen clamp bolts and remove throttle and
manual valve levers from manual valve shaft.
(5) Disconnect park/neutral position switch wires
and remove switch and switch seal.
(6) Remove valve body oil filter.
(7) Remove valve body attaching screws. Lower
valve body slightly and remove accumulator piston
and spring (Fig. 11). Rotate valve body down and
away from case. Pull it forward to disengage park
rod and remove valve body.
(8) Position valve body on bench or on repair stand
for disassembly, cleaning and inspection (Fig. 12).
VALVE BODY SERVICE
The valve body can be disassembled for cleaning
and inspection of the individual components. Valve
body service procedures are detailed in the overhaul
section.
The only serviceable valve body components are:
²park lock rod and E-clip
²switch valve and spring
²pressure adjusting screw bracket
²throttle valve lever
²manual lever
²manual lever shaft seal, washer, E-clip and detent
ball
²fluid filter
²converter clutch solenoid
The remaining valve body components are serviced
only as part of a complete valve body assembly.
VALVE BODY INSTALLATION
(1) Place valve body manual lever in low (1 posi-
tion) so park lock rod can be installed in sprag.
(2) Position park sprag with screwdriver to ease
lock rod installation and engagement.
(3) Install new seals on accumulator piston if nec-
essary and install piston in case. A small amount of
petroleum jelly can be used to hold piston in place.
(4) Lubricate shaft of manual lever and lip of shaft
seal with petroleum jelly.
(5) Raise valve body and align park rod with case
opening and park sprag. Then push rod end through
opening and past sprag. Rotate propeller shaft if nec-
essary.
(6) Position accumulator spring on transfer plate.
Fig. 10 Oil Filter Screw Locations
Fig. 11 Accumulator Piston And Spring
Fig. 12 Valve Body Assembly
21 - 104 30RH/32RH IN-VEHICLE SERVICEJ

ranges. Third gear ratio is 1:1. A separate planetary
gear set provides overdrive operation in fourth gear.
TRANSMISSION RANGES AND SHIFT LEVER
POSITIONS
The AW-4 transmission has six ranges and shift le-
ver positions. Park, Reverse and Neutral are conven-
tional and mechanically operated. The 1-2, 3 and D
ranges provide electronically controlled shifting.
The 1-2 position provides first and second gear
only. The 3 position provides first, second and third
gear.
The D range provides first through fourth gear.
Overdrive fourth gear range is available only when
the shift lever is in D position (Fig. 2).
TRANSMISSION IDENTIFICATION
The transmission I.D. plate is attached to the case
(Fig. 3). The plate contains the transmission serial
and model numbers. Refer to the information on this
plate when ordering service parts.
RECOMMENDED FLUID AND CAPACITY
Recommended and preferred fluid for the AW-4
transmission is Mopar Dexron IIE/Mercon.
Mopar Dexron II can be used but only in emer-
gency situations where Mercon fluid is not available.
Approximate refill capacity for the AW-4 is 8.0 li-
ters (16.9 pints or 8.45 quarts).
COMPONENTS AND OPERATION
ELECTRONIC CONTROLS
The AW-4 is electronically controlled in 1, 2, 3 and
D ranges. Controls consist of the transmission control
module (TCM), valve body solenoids and various sen-
sors. The sensors monitor vehicle speed, throttle
opening, shift lever position and brake pedal applica-
tion.
TRANSMISSION CONTROL MODULE (TCM)
The module determines shift and converter clutch
engagement timing based on signals from sensors.
The valve body solenoids are activated, or deacti-
vated accordingly.
The TCM has a self diagnostic program. Compo-
nent and circuitry malfunctions can be diagnosed
with the DRB scan tool. Once a malfunction is noted
and stored in control module memory, it is retained
even after the problem has been corrected. To cancel
a stored malfunction, disconnect and reconnect the
9Trans.9fuse in the module harness.
TRANSMISSION VALVE BODY SOLENOIDS
The solenoids are mounted on the valve body and
operated by the TCM. The solenoids control operation
of the converter clutch and shift valves in response to
input signals from the module.
SENSORS
Sensors include:
²throttle position sensor (TPS)
²transmission speed sensor
²vehicle speed sensor
²park/neutral position switch
²brake switch
The throttle position sensor is mounted on the
throttle body. It electronically determines throttle po-
sition and relays this information to the transmission
control module to determine shift points and con-
verter clutch engagement.
Fig. 2 AW-4 Shift Lever Positions And Transmission
Ranges
Fig. 3 Transmission Identification
21 - 166 AW-4 AUTOMATIC TRANSMISSIONJ

AW-4 IN-VEHICLE SERVICE
INDEX
page page
Accumulator Pistons and Springs............. 189
Adapter Housing Seal Replacement........... 191
Checking Fluid Level and Condition........... 182
Manual Valve Shaft Seal Replacement......... 187
Park Interlock Cable Adjustment............. 195
Park Rod and Pawl Service................. 190
Park/Neutral Position Switch................ 183
Refilling After Overhaul or Fluid/Filter Change . . . 182
Second Coast Brake Servo................. 190
Shift Cable Adjustment.................... 195
Speed Sensor........................... 192Speed Sensor RotorÐSpeedometer Drive Gear . . 193
Throttle Position Sensor (TPS) Service........ 193
Transmission Control Module (TCM) Service.... 183
Transmission Cooler Line Fittings............ 197
Transmission Cooler Service................ 196
Transmission Throttle Cable Adjustment........ 194
Transmission Throttle Cable Replacement...... 193
Transmission Valve Body Installation.......... 187
Transmission Valve Body Removal........... 186
Transmission Valve Body Solenoids........... 184
CHECKING FLUID LEVEL AND CONDITION
Recommended fluid for AW-4 transmissions is Mo-
par Dexron IIE/Mercon.
Mopar Dexron II can also be used but only when
Mercon fluid is not available.
CHECKING FLUID LEVEL
(1) Be sure transmission fluid is at normal operat-
ing temperature. Normal operating temperature is
reached after approximately 15 miles (25 km) of op-
eration.
(2) Position vehicle on level surface. This is impor-
tant for an accurate fluid level check.
(3) Shift transmission through all gear ranges and
back to Park.
(4) Apply parking brakes.
(5) Verify that transmission is in Park.
(6) Wipe off dipstick handle to prevent dirt from
entering fill tube. Then remove dipstick and check
fluid level and condition.
(7) Correct fluid level isto FULL mark on dip-
stick when fluid is at normal operating temper-
ature(Fig. 1).
(8) If fluid level is low, top off level with Mopar
Dexron IIE/Mercon. Mopar Dexron II can be used but
only if Mercon is not available.Do not overfill
transmission. Add only enough fluid to bring
level to Full mark.
(9) If too much fluid was added, excess amount can
be removed with suction gun and appropriate diame-
ter plastic tubing. Tubing only has to be long enough
to extend into oil pan.
CHECKING FLUID CONDITION
Inspect the appearance of the fluid during the fluid
level check. Fluid color should range from dark red to
pink and be free of foreign material, or particles. If
the fluid is dark brown or black in color and smells
burnt, the fluid has been overheated and must be
changed.Transmission operation should also be checked if
the fluid is severely discolored and contains quanti-
ties of foreign material, metal particles, or clutch disc
friction material.
A small quantity of friction material or metal
particles in the oil pan is normal. The particles
are usually generated during the break-in pe-
riod and indicate normal seating of the various
transmission components.
REFILLING AFTER OVERHAUL OR FLUID/FILTER
CHANGE
The best way to refill the transmission after a fluid
change or overhaul is as follows:
(1) If transmission has been overhauled, install
transmission in vehicle.
(2) Remove dipstick and insert clean funnel in
transmission fill tube.
(3) Add following initial quantity of Mopar Dexron
IIE/Mercon to transmission:
(a) If fluid/filter change was performed, add4
pints (2 quarts)of fluid to transmission.
(b) If transmission was completely overhauled
and torque converter was replaced or drained, add
10 pints (5 quarts)of fluid to transmission.
(c) Remove funnel and install dipstick.
(4) Operate vehicle until fluid reaches normal op-
erating temperature.
(5) Apply parking brakes.
Fig. 1 Transmission Fluid Level
21 - 182 AW-4 IN-VEHICLE SERVICEJ

OPERATING RANGES
NP231 operating ranges are: 2-wheel drive high;
4-wheel drive high and 4-wheel drive low.
2-wheel drive range is for use on all road surfaces.
The 4-wheel drive high and low ranges are undiffer-
entiated and should only be used on unpaved, low
traction surfaces only. The only exception being when
hard surface roads are snow and ice covered.
SHIFT MECHANISM
Operating ranges are selected with a floor mounted
shift lever. The shift lever is connected to the trans-
fer case range lever by an adjustable linkage rod. A
straight line shift pattern is used. Range positions
are marked on the shifter bezel cover plate, or on the
shift knob.
TRANSFER CASE IDENTIFICATION
A circular ID tag is attached to the rear case of
each NP231 transfer case (Fig. 2). The ID tag pro-
vides the transfer case model number, assembly
number, serial number and low range ratio.
The transfer case serial number also represents the
date of build. For example, a serial number of
7-10-94 would represent July 10, 1994.TRANSFER CASE LUBRICANT AND FILL LEVEL
Recommended lubricant for the NP231 transfer
case is Mopar Dexron II.
Approximate lubricant refill capacity is 1.54 liters
(3.25 pints) for YJ and 1.04 liters (2.2 pints) for XJ.
Correct fill level is to the bottom edge of the fill
plug hole. Be sure the vehicle is level to ensure an
accurate fluid level check.
Fig. 2 Transfer Case Identification Tag
21 - 284 NP231 TRANSFER CASEJ