1995 JEEP YJ low oil pressure

(47) Remove rear servo spring retainer snap ring.
Then remove compressor tools and remove rear servo
spring and piston.
OVERHAUL SERVICE INFORMATION
Inspect the transmission bushings during overhaul.
Bushing condition is important as severely worn, or
scored bushings contribute to low pressures, clutch
slip and accelerated wear of other components.How-
ever, do not replace bushings as a matter of
course. Replace bushings only when they are
actually worn, or scored.
Use recommended tools to replace bushings. The
tools are sized and designed to remove, install and
seat bushings correctly. The bushing replacement
tools are included in Bushing Tool Set C-3887-B or
C-3887-J. The bushing tools are manufactured by
Miller Tool Co. and is available through the dealer
tool program.
Pre-sized service bushings are available for replace-
ment purposes. Only the sun gear bushings are not
serviced. Replace the gear as an assembly if the
bushings are worn, or scored.
Heli-Coil inserts are recommended for repairing
damaged, stripped or worn threads in aluminum
parts. These inserts are available from most automo-
tive jobbers. Stainless steel inserts are preferred.
The use of crocus cloth is permissible where neces-
sary. When used on valves, use care to avoid round-
ing off sharp edges. Sharp edges are vital as they
prevent foreign matter from getting between the
valve and valve bore.
Do not reuse oil seals, gaskets, seal rings, or
O-rings during overhaul. Replace these parts as a
matter of course. Also do not reuse snap rings or E-
clips that are bent or distorted. Replace these parts
as well.Lubricate transmission parts with Mopar ATF
Plus, Type 7176 transmission fluid during overhaul
and assembly.
Use petroleum jelly to hold parts like thrust wash-
ers in place during assembly. Use Mopar Door Ease,
Ru-Glyde, or similar products to lubricate piston
seals and O-rings to ease installation. Petroleum jelly
can also be used to prelubricate parts during reas-
sembly if desired.
TRANSMISSION CASE CLEANING AND
INSPECTION
Clean the case in a solvent tank. Flush the case
bores and fluid passages thoroughly with solvent.
Use compressed air to dry the case and clear the
fluid passages. Be sure all solvent is removed from
the case as well.
Do not use shop towels or rags to dry the case
(or any other transmission component) unless
they are made from lint-free materials. Lint
will readily adhere to case surfaces and trans-
mission components and will circulate through-
out the transmission after assembly. A sufficient
quantity of lint can block fluid passages and in-
terfere with valve body operation.
Inspect the case for cracks, porous spots, worn
bores, or damaged threads. Damaged threads can be
repaired with Helicoil thread inserts. However, the
case will have to be replaced if it exhibits any type of
damage or wear.
Lubricate the front band adjusting screw threads
with petroleum jelly and thread the screw part-way
into the case. Be sure the screw turns freely.
Remount the case in a repair stand after cleaning
and inspection.
OVERRUNNING CLUTCHÐLOW-REVERSE
DRUMÐREAR SUPPORT OVERHAUL
DISASSEMBLING OVERRUNNING CLUTCH/
LOW-REVERSE DRUM
If the clutch assembly came out with the low-re-
verse drum, thread two clutch cam bolts into the
cam. Then lift the cam out of the drum with the bolts
(Fig. 30). Rotate the cam back and forth to ease re-
moval if necessary. Remove the clutch roller and
spring assembly from the race afterward.
CLEANING AND INSPECTION
Clean the overrunning clutch assembly, clutch cam,
low-reverse drum and rear support in solvent. Dry
them with compressed air after cleaning.
Inspect condition of each clutch part after cleaning.
Replace the overrunning clutch roller and spring as-
sembly if any rollers or springs are worn or damaged,
or if the roller cage is distorted, or damaged. Replace
the cam if worn, cracked or damaged.
Fig. 29 Compressing Rear Servo Spring
J30RH/32RH TRANSMISSION OVERHAUL 21 - 125

CAUTION: The pump inner gear is a one way fit.
The bore on one side of the gear inside diameter
(I.D.) is chamfered. Be sure the chamfered side
faces forward (to front of pump).
(6) Install new thrust washer on hub of reaction
shaft support. Lubricate washer with transmission
fluid or petroleum jelly.
(7) If reaction shaft seal rings are being replaced,
install new seal rings on support hub (Fig. 59). Lu-
bricate seal rings with transmission fluid or petro-
leum jelly after installation. Squeeze each ring until
ring ends are securely hooked together.
CAUTION: The reaction shaft support seal rings will
break if overspread, or twisted. If new rings are be-
ing installed, spread them only enough for installa-
tion. Also be very sure the ring ends are securely
hooked together after installation. Otherwise, the
rings will either prevent pump installation, or break
during installation.
(8) Install reaction shaft support on pump housing
(Fig. 60).(9) Align reaction support on pump housing. Use
alignment marks made at disassembly. Or, rotate
support until bolt holes in support and pump housing
are all aligned (holes are offset for one-way fit).
(10) Install all bolts that attach support to pump
housing. Then tighten bolts finger tight.
(11) Tighten support-to-pump bolts to required
torque as follows:
(a) Reverse pump assembly and install it in
transmission case. Position pump so bolts are fac-
ing out and are accessible.
(b) Secure pump assembly in case with 2 or 3
bolts, or with pilot studs.
(c) Tighten support-to-pump bolts to 20 Nzm (15
ft. lbs.).
(d) Remove pump assembly from transmission
case.
(12) Install new oil seal in pump with Special Tool
C-4193 and Tool Handle C-4171 (Fig. 61). Be sure
seal lip faces inward.
(13) Install new seal ring around pump housing.
Be sure seal is properly seated in groove.
(14) Lubricate lip of pump oil seal and O-ring seal
with transmission fluid.
FRONT CLUTCH OVERHAUL
FRONT CLUTCH DISASSEMBLY
(1) Remove waved snap ring and remove pressure
plate, clutch plates and clutch discs (Fig. 62).
Fig. 57 Supporting Pump And Installing Outer Gear
Fig. 58 Pump Inner Gear Installation
Fig. 59 Hub Seal Ring Position
Fig. 60 Assembling Reaction Shaft Support And
Pump Housing
21 - 134 30RH/32RH TRANSMISSION OVERHAULJ

The rear planetary ring gear is splined to the out-
put shaft. The front planetary carrier and rear car-
rier ring gear are meshed and rotate as a unit with
the output shaft.
GEARTRAIN OPERATION AND APPLICATION
CHARTS
Operation and application of the first through
fourth and reverse gear elements are outlined in the
function and application charts.
The Component Function Chart (Fig. 7) describes
basic function of various geartrain elements. The
Component Application Chart (Fig. 8) indicates
which elements (including valve body solenoids), are
applied in the various gear ranges.
HYDRAULIC SYSTEM
The hydraulic system consists of the pump, valve
body and solenoids, and four hydraulic accumulators.
The oil pump provides lubrication and operating
pressure.
The valve body controls application of the clutches,
brakes, second coast band, and the converter clutch.
The valve body solenoids control sequencing of the
1-2, 2-3 and 3-4 shift valves. The solenoids are acti-
vated by signals from the transmission control mod-
ule.
The accumulators are used in the clutch and brake
feed circuits to control initial apply pressure. Spring
loaded accumulator pistons modulate the initial
surge of apply pressure for smooth engagement.
OIL PUMP
A gear-type oil pump is used. The pump gears are
mounted in the pump body. The pump drive gear isoperated by the torque converter hub. Drive tangs on
the hub engage in drive slots in the drive gear.
TRANSMISSION VALVE BODY COMPONENTS
Transmission operating pressure is supplied to the
clutch and brake apply circuits through the transmis-
sion valve body. The valve body consists of an upper
body, lower body, separator plate and upper and
lower gaskets (Fig. 9). The various spool valves,
sleeves, plugs and springs are located within the two
body sections.
Fig. 8 Component Application Chart
Fig. 9 Two-Section Transmission Valve Body
JAW-4 AUTOMATIC TRANSMISSION 21 - 169

The manual valve, 1-2 shift valve, primary regula-
tor valve, accumulator control valve, check balls, so-
lenoids and oil strainers are located in the lower
body section (Fig. 10). The remaining control and
shift valves plus check balls and one additional oil
strainer are located in the upper body section (Fig.
11).
Manual Valve
The manual valve is operated by the gearshift link-
age. The valve diverts fluid to the apply circuits ac-
cording to shift lever position.Primary Regulator Valve
The primary regulator valve (Fig. 13) modulates
line pressure to the clutches and brakes according to
engine load. The valve is actuated by throttle valve
pressure.
During high load operation, the valve increases line
pressure to maintain positive clutch and brake en-
gagement. At light load, the valve decreases line
pressure just enough to maintain smooth engage-
ment.
Fig. 10 Upper Body Components
Fig. 11 Lower Body Components
21 - 170 AW-4 AUTOMATIC TRANSMISSIONJ

PRESSURE TEST ANALYSIS
If pressures in D and Reverse are higher than
specified in test, check for the following:
²throttle cable loose, worn, binding or out of adjust-
ment
²throttle valve, downshift plug, throttle cam, or pri-
mary regulator valve are sticking, worn or damaged
If pressures in D and Reverse are lower than spec-
ified in test, check for following:
²throttle cable loose, worn, binding or out of adjust-
ment
²throttle valve, downshift plug, or throttle cam
sticking, worn or damaged
²primary regulator valve sticking, worn, or dam-
aged
²oil pump gears or housing worn, or damaged
²overdrive clutch worn, or damaged
If pressures are low in D range only, check for fol-
lowing:
²forward clutch worn or damaged
²fluid leakage in D range circuit (component seal
and O-rings)
If pressures are low in Reverse only, check for fol-
lowing:
²shift cable and manual valve out of adjustment
²fluid leakage in reverse circuit (component seal
and O-rings)
²direct clutch worn or damaged
²first/reverse brake worn or damaged
TORQUE CONVERTER STALL TEST
Stall testing checks the holding ability of the trans-
mission clutches and brakes and of the torque con-
verter stator overrunning clutch.Stall speeds are
checked in both Drive and Reverse ranges with
the AW-4 transmission.
(1) Before starting test, be sure fluid level is cor-
rect and fluid is at normal operating temperature.
(2) Connect tachometer to engine. Position tachom-
eter so it can be viewed from drivers seat.
(3) Apply parking brakes and block wheels.
(4) Apply and hold service brakes.
(5) Shift transfer case into 2H position.
(6) Start engine.
WARNING: DO NOT ALLOW ANYONE TO STAND AT
THE FRONT OR REAR OF THE VEHICLE DURING
THE TEST.
(7) Shift transmission into D range.
(8) Open throttle completely and record maximum
engine rpm registered on tachometer. It takes any-
where from 4 to 10 seconds to reach maximum rpm.
However, once maximum rpm has been achieved,do
not hold wide open throttle for more than 3-4
seconds.CAUTION: Stalling the converter causes a rapid in-
crease in fluid temperature. To avoid fluid overheat-
ing, hold wide open throttle for no more than 4
seconds after reaching peak rpm. In addition, if
more than one stall test is required, run the engine
at 1000 rpm with the transmission in Neutral for at
least 20 seconds to cool the fluid.
(9) Stall speed should be in 2100-2400 rpm range
in Drive.
(10) Release throttle, shift transmission into Neu-
tral, and run engine for 20-30 seconds to cool fluid.
(11) Shift transmission into Reverse.
(12) Repeat stall test described in step (8).
(13) Stall speed in Reverse should also be in 2100-
2400 rpm range.
(14) Release accelerator pedal, shift transmission
into Neutral, and run engine for 20-30 seconds to
cool fluid.
STALL SPEED TEST ANALYSIS
If engine rpm is lower than specified in D and Re-
verse, check for the following:
²engine output/performance insufficient
²stator overrunning clutch in torque converter not
holding if engine speed was 1500 rpm or less.
If stall speed in D range is higher than specified,
check for the following:
²line pressure low
²forward clutch slipping
²No. 2 one-way clutch not holding
²overdrive one-way clutch not holding
If stall speed in Reverse was higher than specified,
check for the following:
²line pressure low
²direct clutch slipping
²first/ reverse brake slipping
²overdrive one-way clutch not holding
If stall speeds were higher than specified in both D
and Reverse, check for the following:
²low fluid level
²line pressure low
²overdrive one-way clutch not holding
TIME LAG TEST
This test checks general condition of the overdrive
clutch, forward clutch, rear clutch and first/reverse
brake. Condition is indicated by the amount of time
required for clutch/brake engagement with the en-
gine at curb idle speed. Engagement time is mea-
sured for D and Reverse positions. A stop watch is
recommended for test accuracy.
TEST PROCEDURE
(1) Check and adjust transmission fluid level if
necessary.
(2) Bring transmission to normal operating tem-
perature.
21 - 178 AW-4 TRANSMISSION DIAGNOSISJ

the front bumper and radiator support be removed
for access to the cooler lines and attaching bracket.
REVERSE FLUSHING MAIN AND AUXILIARY
COOLERS AND COOLER LINES
Reverse flushing the cooler and lines will prevent
sludge and particles from flowing back into the
transmission after repair. The flushing procedure ap-
plies to standard (in-radiator) coolers and auxiliary
coolers equally.
Pressure equipment is preferred for reverse flush-
ing. However, reverse flushing can be performed us-
ing hand operated equipment as described in the
following procedure.
(1) Disconnect cooler lines at transmission and at
auxiliary cooler (Figs. 48 and 49).
(2) Position drain pan under cooler line to catch
material flushed through coolers and lines.
(3) Reverse flush each cooler using hand operated
suction gun filled with mineral spirits. Insert gun
nozzle (or hose) into cooler inlet (return) line. Then
force mineral spirits through into line and through
cooler.
(4) Continue reverse flushing until fluid exiting in-
let (pressure) line is clear and free of debris/residue.
(5) Replace radiator if fluid cannot be pumped
through main cooler. Replace auxiliary cooler if leaks
are evident, or if fluid cannot be pumped through it.
(6) Clear flushing materials from coolers and lines
with short pulses of compressed air. Insert air gun
nozzle into cooler inlet (return) line and continue
short pulses of air until all fluid is cleared from
cooler and lines.(7) Pump one quart of fresh automatic transmis-
sion fluid through cooler and lines before reconnect-
ing cooler lines.
FLOW TESTING TRANSMISSION MAIN
COOLER
Cooler flow is checked by measuring the amount of
fluid flow through the cooler in a 20 second time pe-
riod. The test is performed with the engine running
and transmission in neutral. Fluid is then pumped
through the cooler by the transmission oil pump.
(1) Disconnect cooler inlet line at transmission fit-
ting.
(2) Securely attach hose to end of inlet line and po-
sition line in a one quart test container.
(3) Add extra quart of fluid to transmission.
(4) Use stopwatch to check flow test time.
(5) Shift transmission into neutral and set parking
brake.
(6) Start and run engine at curb idle speed and im-
mediately note cooler flow. Approximately one quart
of fluid should flow into test container in 20 second
period.
(7) If cooler flow is intermittent, flows less than
one quart in 20 seconds, or does not flow at all,
cooler is faulty and must be replaced.
TRANSMISSION COOLER LINE FITTINGS
Quick connect fittings are used at the transmission
cooler line connections. The fitting seals and guides
are serviceable.
Replace the seals and guides whenever the fittings
exhibit leakage, or will not properly snap into place.
Fig. 49 Auxiliary Cooler Mounting (Right Hand Drive)
JAW-4 IN-VEHICLE SERVICE 21 - 197

AW-4 TRANSMISSION OVERHAUL
INDEX
page page
Cleaning and Inspection................... 214
Direct Clutch Overhaul.................... 228
First-Reverse Brake Piston and Transmission Case
Overhaul............................. 247
Forward Clutch Overhaul................... 232
Front Planetary Gear Overhaul.............. 237
Manual Valve Shaft Overhaul............... 215
Oil Pump Overhaul....................... 216
Overdrive Planetary Gear and Clutch Overhaul . . 218Overdrive Support Overhaul................ 226
Overhaul Service Tools.................... 201
Rear Planetary, No. 2 One-Way Clutch and Output
Shaft Overhaul......................... 244
Second Brake Overhaul................... 241
Sun Gear and No. 1 One-Way Clutch Overhaul . . 238
Transmission Assembly and Adjustment........ 265
Transmission Disassembly................. 201
Transmission Valve Body Overhaul........... 250
OVERHAUL SERVICE TOOLS
The special tools needed to overhaul the AW-4
transmission are provided in Tool Kit 6294. However,
Pressure Test Port Adapter 7554 is not included in
this kit and must be ordered separately. The over-
haul tool kit and test port adapter are available
through the parts division and dealer special tool
program.
TRANSMISSION DISASSEMBLY
(1) Remove torque converter.
(2) Remove lower half of filler tube if not previ-
ously removed.
(3) Remove clamps attaching wire harness and
throttle cable (Fig. 1) to transmission.(4) Remove shift lever from manual valve shaft at
left side of transmission.
(5) Remove park/neutral position switch.
(6) Remove speed sensor (Fig. 2).
Fig. 1 Typical Harness And Cable Clamp Attachment
Fig. 2 Speed Sensor Removal
JAW-4 TRANSMISSION OVERHAUL 21 - 201

(2) Remove oil strainers (Fig. 2).
(3) Note or mark position of valve retainers and
pressure reducing plug clip for assembly reference
(Fig. 2). Do not remove the retainers at this time.
(4) Remove solenoid No. 1, 2 and 3. Discard sole-
noid O-rings.
(5) Remove 1-2 shift valve retainer (Fig. 3).
(6) Remove 1-2 shift valve plug, valve spring and
valve (Fig. 4).
(7) Remove primary regulator valve as follows:
WARNING: THE PRIMARY REGULATOR VALVE
SLEEVE AND PLUNGER ARE UNDER TENSION
FROM THE VALVE SPRING. EXERT COUNTER-
PRESSURE ON THE SPRING WHILE REMOVING
THE VALVE RETAINER TO PREVENT COMPONENTS
FROM FLYING OUT.(a) Note position of valve retainer for assembly
reference (Fig. 5). Then press valve sleeve inward
with your thumb and remove retainer with magnet.
(b) Slowly release thumb pressure on sleeve and
remove sleeve, spring and washer and valve (Fig.
6). Use magnet to remove valve if necessary.
(8) Remove regulator valve plunger from sleeve
(Fig. 7).
(9) Remove retaining clip and remove pressure re-
ducing plug (Fig. 8). Cover screwdriver blade with
tape to avoid scratching valve body surface.
(10) Remove accumulator control valve retainer
and remove control valve assembly (Fig. 9).
(11) Remove spring and control valve from valve
sleeve (Fig. 10).
(12) Clean lower body valve components with sol-
vent and dry them with compressed air only. Do not
Fig. 2 Valve Retainer And Clip Location
Fig. 3 Removing 1-2 Shift Valve Retainer
Fig. 4 Removing/Installing 1-2 Shift Valve
Fig. 5 Regulator Valve Retainer Position
JAW-4 TRANSMISSION OVERHAUL 21 - 253