transmission repair JEEP CHEROKEE 1995 Service Owner's Manual

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

(4) Apply thick soapy water solution to suspected
leak areas.
CAUTION: The recommended test pressure is 8 psi.
The maximum allowable test pressure is 10 psi. Do
not exceed specified test pressure.
(5) Pressurize transmission to 8 psi with air pump.
(6) Observe suspected leak areas. Air bubbles ap-
pearing in soapy water solution indicate leak points.
(7) Remove test tools and plugs after test comple-
tion and make necessary repairs as described in Leak
Correction procedure.
CONVERTER HOUSING AREA LEAK
CORRECTION
(1) Remove converter.
(2) Tighten front band adjusting screw until band
is tight around clutch retainer. This prevents
clutches from coming out when oil pump is removed.
(3) Remove oil pump and seal. Inspect pump hous-
ing drainback and vent holes for obstructions. Clear
holes with solvent and wire.(4) Inspect pump bushing and converter hub. If
bushing is scored, replace it. If converter hub is
scored, either polish it with crocus cloth or replace
converter if scoring is severe.
(5) Install new pump seal, O-ring, gasket, bushing.
Replace oil pump if cracked, porous or damaged in
any way.
(6) Loosen kickdown lever pin plug two turns. Ap-
ply Permatex No. 2 or equivalent to plug threads and
tighten plug to 17 Nzm (150 in-lbs) torque.
(7) Adjust front band.
(8) Lubricate pump seal and converter hub with
transmission fluid or petroleum jelly and install con-
verter.
(9) Install transmission.
(10) Install converter housing dust shield and
lower vehicle.
DIAGNOSIS GUIDES AND CHARTS
The diagnosis charts provide additional reference
for transmission and converter clutch diagnosis.
The hydraulic flow charts outline fluid flow and hy-
draulic circuitry. Circuit operation is provided for all
gear ranges. Normal working pressures are also sup-
plied for each of the various gear ranges.
Fig. 15 Vent Plug And Hub Seal Cup Installation
Fig. 16 Pressurizing Transmission
J30RH/32RH TRANSMISSION DIAGNOSIS 21 - 77

(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

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

CONNECTING COOLER LINES AND FITTINGS
(ALL TYPES)
(1) Wipe cooler line and fitting clean with shop
towel.
(2) Insert cooler line into fitting. Then push line
inward until retainer or insert secures line. A snap or
click sound will be heard when the insert tabs or re-
tainer clip seats behind the cooler line flange.
(3)Pull outward on cooler lines/fittings to
verify they are properly secured.
CAUTION: The wire retainer clips or insert release
tabs secure the cooler lines. If the clips or tabs are
deformed, distorted, or not fully seated, normal
fluid pressure could unseat the lines resulting in
fluid loss and transmission damage. Be very sure
the cooler lines are firmly secured as described in
step (3).
CONVERTER DRAINBACK CHECK VALVE SERVICE
The converter drainback check valve is located in
the cooler outlet (pressure) line near the radiator
lower tank. The valve prevents fluid drainback when
the vehicle is parked for lengthy periods. The valve
check ball is spring loaded and has an opening pres-
sure of approximately 2 psi. Refer to the cooler flow
test procedure for valve testing.
The valve is serviced as an assembly; it is not re-
pairable. Do not clean the valve if restricted, or con-
taminated by sludge, or debris. If the valve fails, or if
a transmission malfunction occurs that generates
sludge and/or clutch particles and metal shavings,
the valve must be replaced.
The valve must be removed whenever the cooler
and lines are reverse flushed. The valve can be flow
tested when necessary. The procedure is exactly the
same as for flow testing a cooler.
If the valve is restricted, installed backwards, or in
the wrong line, it will cause an overheat condition
and possible transmission failure.
CAUTION: The drainback valve is a one-way valve.
As such, it must be properly oriented in terms of
flow direction. In addition, the valve must only beinstalled in the pressure line. Otherwise flow will be
blocked causing overheat and eventual transmis-
sion failure.
TRANSMISSION COOLER FLOW TESTING
The transmission main and auxiliary coolers, plus
the drainback valve, should be flow tested whenever
fluid overheating is noted.
Restricted flow caused by contamination, or a
cooler malfunction, reduces lubrication fluid flow
throughout the transmission. This can result in fluid
overheating, fluid breakdown, bushing wear, shift
problems and component failure.
Normal color of transmission fluid varies from
bright red, to light pink. Fluid overheating is indi-
cated when fluid color ranges from orange-brown to
black, and the fluid smells burned, or contains
sludge.
CAUTION: If a transmission malfunction contami-
nates the fluid with clutch disc and metal particles,
the cooler and lines must be reverse flushed thor-
oughly. Flushing will prevent sludge and particles
from flowing back into the transmission and con-
verter after repair.
Cooler flow is tested by measuring the amount of
fluid pumped through the cooler in a specified time
by the transmission oil pump.The same flow test
procedure is used for the drainback valve, main
cooler, and auxiliary cooler.
Cooler And Drainback Valve Flow Test Procedure
(1) Test flow throughdrainback valveas follows:
(a) Add extra quart of ATF Plus to transmission.
(b) Disconnect pressure line at radiator fitting, or
at drainback valve and position hose or valve end
in one quart test container.
(c) Shift transmission into neutral, run engine at
idle speed for 20 seconds, and note flow from valve.
Use stopwatch to check test time.
(d) Replace drainback valve if flow is less than
one quart in 20 seconds, is intermittent, or does
not flow at all.
(e) Connect pressure hose to radiator fitting and
proceed to cooler flow test.
(2) Test flow throughmain cooleras follows:
(a) Disconnect cooler return (rear) line at trans-
mission and place it in one quart test container.
(b) Add extra quart of fluid to transmission.
(c) Shift transmission into neutral, run engine at
idle speed for 20 seconds, and note flow from valve.
Use stopwatch to check test time.
(d) Replace cooler if fluid flow is less than one
quart in 20 seconds, is intermittent, or does not
flow at all.
Fig. 33 New Style Fitting Insert (On Cooler Line)
J30RH/32RH IN-VEHICLE SERVICE 21 - 113

grip the metal part of the seal. Then tighten the tool
puller screw to withdraw the seal from the pump
body.
Use Special Tool C-4193-A to install the seal (Fig.
6). Be sure to lubricate the pump seal and converter
hub with transmission fluid before installation.
TRANSMISSION AND CONVERTER INSTALLATION
CAUTION: If the transmission was repaired to cor-
rect a problem that generated sludge and debris,
the fluid cooler and lines must be reverse flushed
and the torque converter and drainback valve re-
placed. Sludge and metal or friction particles must
be removed from the cooler system before reinstall-
ing the transmission. This avoids re-contaminating
the repaired transmission. Failure to flush the sys-
tem will result in repeat failure and a shop come-
back.
(1) Lubricate converter drive hub and pump seal
with Mopar ATF Plus transmission fluid. Then in-
stall converter. Turn converter back and forth toalign drive slots in converter hub with pump gear
lugs. Be sure converter is fully seated in pump (Fig.
7).
(2) Temporarily secure converter with C-clamp or
metal strap attached across converter housing.
(3) Position transmission on jack and secure it
with safety chains.
(4) Raise transmission and align converter with
drive plate.
(5) Move transmission forward. Then raise, lower
or tilt transmission to align converter housing with
engine block dowels.
(6) Install two transmission attaching bolts.
Tighten bolts just enough to hold transmission con-
verter housing in place on block.
(7) Install torque converter attaching bolts.
Tighten bolts to following torque.
²54 Nzm (40 ft. lbs.) with 9.5 in. 3-lug converter
²74 Nzm (55 ft. lbs.) with 9.5 in. 4-lug converter
²74 Nzm (55 ft. lbs.) with 10.0 in. 4-lug converter
²31 Nzm (270 in. lbs.) with 10.75 in. 4-lug converter
(8) Install and tighten remaining bolts that attach
transmission converter housing to engine block (Fig.
8).
CAUTION: Be sure the converter housing is fully
seated on the engine block dowels before tighten-
ing any bolts.
(9) Install crankshaft position sensor.
(10) Install transmission fill tube and O-ring (Fig.
5).
(11) Connect transmission cooler lines to fittings.
Refer to Figure 9 for cooler line identification.
Fig. 5 Pump Seal Removal
Fig. 6 Pump Seal Installation
Fig. 7 Checking Torque Converter Seating
J30RH/32RH TRANSMISSION REMOVAL AND INSTALLATION 21 - 117

30RH/32RH TRANSMISSION OVERHAUL
INDEX
page page
Adapter/Extension Housing Inspection and Park
Lock Component Overhaul................ 127
Front Clutch Overhaul..................... 134
Front Servo and Band Overhaul............. 146
Governor and Park Gear Overhaul........... 127
Oil Pump Overhaul....................... 131
Overhaul Service Information................ 125
Overrunning ClutchÐLow-Reverse DrumÐRear
Support Overhaul....................... 125
Planetary Gear Train Overhaul.............. 141Rear Clutch Overhaul..................... 138
Rear Servo and Band Overhaul.............. 146
Transmission Assembly and Adjustment Procedures. 155
Transmission Assembly Tips................ 155
Transmission Case Cleaning and Inspection.... 125
Transmission Disassembly.................. 119
Valve Body Assembly and Adjustment......... 153
Valve Body Disassembly and Inspection....... 147
TRANSMISSION DISASSEMBLY
(1) Clean transmission exterior with steam gun or
with solvent. Wear eye protection during cleaning
process.
(2) Remove throttle and shift levers from valve
body manual shaft and throttle lever shaft.
(3) Mount transmission in repair stand C-3750-B
(Fig. 1).
(4) Remove nuts attaching adapter, or extension
housing to transmission case.
(5) Remove adapter/extension housing and gasket
(Fig. 2).
(6) Remove rear bearing and snap ring, if
equipped.(7) Remove park/neutral position switch and seal
(Fig. 3).
Fig. 1 Transmission Mounted On Typical Repair
Stand
Fig. 2 Adapter Housing Removal/Installation (4 x 4
Models)
Fig. 3 Park/Neutral Position Switch Removal/
Installation
J30RH/32RH TRANSMISSION OVERHAUL 21 - 119

(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

AW-4 TRANSMISSION DIAGNOSIS
INDEX
page page
General Diagnosis Information............... 176
Hydraulic Pressure Test.................... 177
Manual Shifting Test...................... 177Preliminary Inspection and Adjustment......... 176
TimeLagTest ........................... 178
Torque Converter Stall Test................. 178
GENERAL DIAGNOSIS INFORMATION
Shift points are controlled by the transmission con-
trol module (TCM). Before attempting repair, deter-
mine if a malfunction is electrical or mechanical.
The TCM used with the AW-4 transmission has a
self-diagnostic program compatible with the DRB
scan tool. The tester will identify faults in the elec-
trical control system.
Diagnosis should begin with the Preliminary Inspec-
tion And Adjustment procedure. It is will help deter-
mine if a problem is mechanical or electrical. The first
procedure step is Initial Inspection and Adjustment.
PRELIMINARY INSPECTION AND ADJUSTMENT
(1) Check and adjust transmission shift cable if
necessary.
Fig. 26 Preliminary Diagnosis Check Procedure
21 - 176 AW-4 TRANSMISSION DIAGNOSISJ

(2) Verify transmission throttle cable operation.
Repair or replace cable if necessary.
(3) Check engine throttle operation. Operate accel-
erator pedal and observe injector throttle plate move-
ment. Adjust linkage if throttle plate does not reach
wide open position.
(4) Check transmission fluid level when fluid is at
normal operating temperature. Start engine. Shift
transmission through all gear ranges then back to
Neutral. Correct level is to Full or Add mark on dip-
stick with engine at curb idle speed.
(5) Check and adjust park/neutral position switch
if necessary.
(6) Check throttle position sensor adjustment and
operation. Adjust the sensor if necessary.
MANUAL SHIFTING TEST
(1) This test determines if problem is related to
mechanical or electrical component.
(2) Stop engine and disconnect transmission con-
trol module or module fuse.
(3) Road test vehicle. Shift transmission into each
gear range. Transmission should operate as follows:
²lock in Park
²back up in Reverse
²not move in Neutral
²provide first gear only with shift lever in 1-2 posi-
tion
²operate in third gear only with shift lever in 3 po-
sition
²operate in overdrive fourth gear in D position
(4) If transmission operates as described, proceed
to next step. However, if forward gear ranges were
difficult to distinguish (all feel the same), or vehicle
would not back up, refer to diagnosis charts. Do not
perform stall or time lag tests.
CAUTION: Do not overspeed the engine during the
next test step. Ease off the throttle and allow the
vehicle to slow before downshifting.
(5) Continue road test. Manually downshift trans-
mission from D to 3, and from 3 to 1-2 position. Then
manually upshift transmission through forward
ranges again.
(6) If transmission operation is OK, perform stall,
time lag and pressure tests. If transmission shifting
problem is encountered, refer to diagnosis charts.
(7) If a problem still exists, continue testing with
DRB scan tool.
HYDRAULIC PRESSURE TEST
PRESSURE TEST PROCEDURE
(1) Connect pressure test gauge to test port on pas-
senger side of transmission. Use Adapter 7554 to con-
nect gauge. Be sure test gauge has minimum
capacity of 300 psi (2100 kPa).(2) Be sure transmission fluid is at normal operat-
ing temperature.
(3) Apply parking brakes and block wheels.
WARNING: DO NOT ALLOW ANYONE TO STAND
AT THE FRONT OR REAR OF THE VEHICLE WHILE
PERFORMING THE FOLLOWING STEPS IN THE
PRESSURE TEST.
(4) Check and adjust engine curb idle speed.
(5) Apply (and hold) service brakes.
(6) Shift transmission into D range and note line
pressure with engine at curb idle speed. Pressure
should be 61-to-70 psi (421-to-481 kPa).
(7) Press accelerator pedal to wide open throttle
position and note line pressure. Pressure should be
173-to-209 psi (1196-to-1442 kPa).
CAUTION: Do not hold wide open throttle for more
than 3-4 seconds at a time.
(8) Shift transmission into Reverse and note line
pressure with engine at curb idle speed. Pressure
should be 75-to-90 psi (519-to-618 kPa).
(9) Press accelerator to wide open throttle position
and note line pressure in Reverse. Pressure should
be 213-to-263 psi (1471-to-1814 kPa).
CAUTION: Do not hold wide open throttle for more
than 4 seconds.
(10) If line pressure is not within specifications,
adjust transmission throttle cable and repeat pres-
sure test.
Fig. 27 Pressure Test Gauge Connection
JAW-4 TRANSMISSION DIAGNOSIS 21 - 177