2002 JEEP GRAND CHEROKEE turn

Test Four - Transmission In Reverse
NOTE: This test checks pump output, pressure reg-
ulation and the front clutch and rear servo circuits.
Use 300 psi Test Gauge C-3293-SP for this test.
(1) Leave vehicle on hoist and leave gauge C-3292
in place at accumulator port.
(2) Move 300 psi Gauge C-3293-SP back to rear
servo port.
(3) Have helper start and run engine at 1600 rpm
for test.
(4) Move transmission shift lever four detents
rearward from full forward position. This is Reverse
range.
(5) Move transmission throttle lever fully forward
then fully rearward and note reading at Gauge
C-3293-SP.
(6) Pressure should be 145 - 175 psi (1000-1207
kPa) with throttle lever forward and increase to 230 -
280 psi (1586-1931 kPa) as lever is gradually moved
rearward.
Test Five - Governor Pressure
NOTE: This test checks governor operation by mea-
suring governor pressure response to changes in
vehicle speed. It is usually not necessary to check
governor operation unless shift speeds are incor-
rect or if the transmission will not downshift. The
test should be performed on the road or on a hoist
that will allow the rear wheels to rotate freely.
(1) Move 100 psi Test Gauge C-3292 to governor
pressure port.
(2) Move transmission shift lever two detents rear-
ward from full forward position. This is D range.
(3) Have helper start and run engine at curb idle
speed. Then firmly apply service brakes so wheels
will not rotate.
(4) Note governor pressure:
²Governor pressure should be no more than 20.6
kPa (3 psi) at curb idle speed and wheels not rotat-
ing.
²If pressure exceeds 20.6 kPa (3 psi), a fault
exists in governor pressure control system.
(5) Release brakes, slowly increase engine speed,
and observe speedometer and pressure test gauge (do
not exceed 30 mph on speedometer). Governor pres-
sure should increase in proportion to vehicle speed.
Or approximately 6.89 kPa (1 psi) for every 1 mph.
(6) Governor pressure rise should be smooth and
drop back to no more than 20.6 kPa (3 psi), after
engine returns to curb idle and brakes are applied to
prevent wheels from rotating.
(7) Compare results of pressure test with analysis
chart.Test Six - Transmission In Overdrive Fourth Gear
NOTE: This test checks line pressure at the over-
drive clutch in fourth gear range. Use 300 psi Test
Gauge C-3293-SP for this test. The test should be
performed on the road or on a chassis dyno.
(1) Remove tachometer; it is not needed for this
test.
(2) Move 300 psi Gauge to overdrive clutch pres-
sure test port. Then remove other gauge and reinstall
test port plug.
(3) Lower vehicle.
(4) Turn OD switch on.
(5) Secure test gauge so it can be viewed from
drivers seat.
(6) Start engine and shift into D range.
(7) Increase vehicle speed gradually until 3-4 shift
occurs and note gauge pressure.
(8) Pressure should be 469-496 kPa (68-72 psi)
with closed throttle and increase to 620-827 kPa (90-
120 psi) at 1/2 to 3/4 throttle. Note that pressure can
increase to around 896 kPa (130 psi) at full throttle.
(9) Return to shop or move vehicle off chassis
dyno.
PRESSURE TEST ANALYSIS CHART
TEST CONDITION INDICATION
Line pressure OK during
any one testPump and regulator
valve OK
Line pressure OK in R
but low in D, 2, 1Leakage in rear clutch
area (seal rings, clutch
seals)
Pressure low in D Fourth
Gear RangeOverdrive clutch piston
seal, or check ball
problem
Pressure OK in 1, 2 but
low in D3 and RLeakage in front clutch
area
Pressure OK in 2 but low
in R and 1Leakage in rear servo
Front servo pressure in 2 Leakage in servo; broken
servo ring or cracked
servo piston
Pressure low in all
positionsClogged filter, stuck
regulator valve, worn or
faulty pump, low oil level
Governor pressure too
high at idle speedGovernor pressure
solenoid valve system
fault. Refer to diagnostic
book.
21 - 14 AUTOMATIC TRANSMISSION - 42REWJ
AUTOMATIC TRANSMISSION - 42RE (Continued)

leaks are generally deposited on the housing and not
on the converter.
TORQUE CONVERTER LEAK POINTS
Possible sources of converter leaks are:
(1) Leaks at the weld joint around the outside
diameter weld (Fig. 12).
(2) Leaks at the converter hub weld (Fig. 12).
CONVERTER HOUSING AREA LEAK CORRECTION
(1) Remove converter.
(2) Tighten front band adjusting screw until band
is tight around front clutch retainer. This prevents
front/rear clutches from coming out when oil pump is
removed.
(3) Remove oil pump and remove pump seal.
Inspect pump housing 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.(5) Install new pump seal, O-ring, and gasket.
Replace oil pump if cracked, porous or damaged in
any way. Be sure to loosen the front band before
installing the oil pump, damage to the oil pump seal
may occur if the band is still tightened to the front
clutch retainer.
(6) Loosen kickdown lever pin access plug three
turns. Apply LoctiteŸ 592, or PermatextNo.2to
plug threads and tighten plug to 17 N´m (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 and converter housing
dust shield.
(10) Lower vehicle.
DIAGNOSIS AND TESTING - DIAGNOSIS
CHARTS
The diagnosis charts provide additional reference
when diagnosing a transmission fault. The charts
provide general information on a variety of transmis-
sion, overdrive unit and converter clutch fault condi-
tions.
The hydraulic flow charts in the Schematics and
Diagrams section of this group, outline fluid flow and
hydraulic circuitry. Circuit operation is provided for
PARK, NEUTRAL, FIRST, SECOND, THIRD,
FOURTH, MANUAL FIRST, MANUAL SECOND,
and REVERSE gear ranges. Normal working pres-
sures are also supplied for each of the gear ranges.
Fig. 11 Converter Housing Leak Paths
1 - PUMP SEAL
2 - PUMP VENT
3 - PUMP BOLT
4 - PUMP GASKET
5 - CONVERTER HOUSING
6 - CONVERTER
7 - REAR MAIN SEAL LEAK
Fig. 12 Converter Leak Points - Typical
1 - OUTSIDE DIAMETER WELD
2 - TORQUE CONVERTER HUB WELD
3 - STARTER RING GEAR
4 - LUG
21 - 16 AUTOMATIC TRANSMISSION - 42REWJ
AUTOMATIC TRANSMISSION - 42RE (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
SHIFTS DELAYED OR
ERRATIC (SHIFTS
ALSO HARSH AT
TIMES)1. Fluid Level Low/High. 1. Correct fluid level and check for leaks if low.
2. Fluid Filter Clogged. 2. Replace filter. If filter and fluid contained clutch
material or metal particles, an overhaul may be
necessary. Perform lube flow test.
3. Throttle Linkage Mis-adjusted. 3. Adjust linkage as described in service section.
4. Throttle Linkage Binding. 4. Check cable for binding. Check for return to
closed throttle at transmission.
5. Gearshift Linkage/Cable
Mis-adjusted.5. Adjust linkage/cable as described in service
section.
6. Clutch or Servo Failure. 6. Remove valve body and air test clutch, and
band servo operation. Disassemble and repair
transmission as needed.
7. Governor Circuit Electrical Fault. 7. Test using DRBTscan tool and repair as
required.
8. Front Band Mis-adjusted. 8. Adjust band.
9. Pump Suction Passage Leak. 9. Check for excessive foam on dipstick after
normal driving. Check for loose pump bolts,
defective gasket. Replace pump assembly if
needed.
NO REVERSE (D
RANGES OK)1. Gearshift Linkage/Cable
Mis-adjusted/Damaged.1. Repair or replace linkage parts as needed.
2. Park Sprag Sticking. 2. Replace overdrive annulus gear.
3. Rear Band Mis-adjusted/Worn. 3. Adjust band; replace.
4. Valve Body Malfunction. 4. Remove and service valve body. Replace valve
body if any valves or valve bores are worn or
damaged.
5. Rear Servo Malfunction. 5. Remove and disassemble transmission.
Replace worn/damaged servo parts as necessary.
6. Direct Clutch in Overdrive Worn. 6. Disassemble overdrive. Replace worn or
damaged parts.
7. Front Clutch Burnt. 7. Remove and disassemble transmission.
Replace worn, damaged clutch parts as required.
HAS FIRST/REVERSE
ONLY (NO 1-2 OR 2-3
UPSHIFT)1. Governor Circuit Electrical Fault. 1. Test using DRBTscan tool and repair as
required.
2. Valve Body Malfunction. 2. Repair stuck 1-2 shift valve or governor plug.
3. Front Servo/Kickdown Band
Damaged/Burned.3. Repair/replace.
MOVES IN 2ND OR
3RD GEAR,
ABRUPTLY
DOWNSHIFTS TO
LOW1. Valve Body Malfunction. 1. Remove, clean and inspect. Look for stuck 1-2
valve or governor plug.
WJAUTOMATIC TRANSMISSION - 42RE 21 - 19
AUTOMATIC TRANSMISSION - 42RE (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
NO LOW GEAR
(MOVES IN 2ND OR
3RD GEAR ONLY)1. Governor Circuit Electrical Fault. 1. Test with DRBTscan tool and repair as
required.
2. Valve Body Malfunction. 2. Remove, clean and inspect. Look for sticking
1-2 shift valve, 2-3 shift valve, governor plug or
broken springs.
3. Front Servo Piston Cocked in
Bore.3. Inspect servo and repair as required.
4. Front Band Linkage Malfunction 4. Inspect linkage and look for bind in linkage.
NO KICKDOWN OR
NORMAL
DOWNSHIFT1. Throttle Linkage Mis-adjusted. 1. Adjust linkage.
2. Accelerator Pedal Travel
Restricted.2. Verify floor mat is not under pedal, repair worn
accelerator cable or bent brackets.
3. Valve Body Hydraulic Pressures
Too High or Too Low Due to Valve
Body Malfunction or Incorrect
Hydraulic Control Pressure
Adjustments.3. Perform hydraulic pressure tests to determine
cause and repair as required. Correct valve body
pressure adjustments as required.
4. Governor Circuit Electrical Fault. 4. Test with DRBTscan tool and repair as
required.
5. Valve Body Malfunction. 5. Perform hydraulic pressure tests to determine
cause and repair as required. Correct valve body
pressure adjustments as required.
6. TPS Malfunction. 6. Replace sensor, check with DRBTscan tool.
7. PCM Malfunction. 7. Check with DRBTscan tool and replace if
required.
8. Valve Body Malfunction. 8. Repair sticking 1-2, 2-3 shift valves, governor
plugs, 3-4 solenoid, 3-4 shift valve, 3-4 timing
valve.
STUCK IN LOW
GEAR (WILL NOT
UPSHIFT)1. Throttle Linkage Mis-adjusted/
Stuck.1. Adjust linkage and repair linkage if worn or
damaged. Check for binding cable or missing
return spring.
2. Gearshift Linkage Mis-adjusted. 2. Adjust linkage and repair linkage if worn or
damaged.
3. Governor Component Electrical
Fault.3. Check operating pressures and test with DRBT
scan tool, repair faulty component.
4. Front Band Out of Adjustment. 4. Adjust Band.
5. Clutch or Servo Malfunction. 5. Air pressure check operation of clutches and
bands. Repair faulty component.
CREEPS IN
NEUTRAL1. Gearshift Linkage Mis-adjusted. 1. Adjust linkage.
2. Rear Clutch Dragging/Warped. 2. Disassemble and repair.
3. Valve Body Malfunction. 3. Perform hydraulic pressure test to determine
cause and repair as required.
21 - 20 AUTOMATIC TRANSMISSION - 42REWJ
AUTOMATIC TRANSMISSION - 42RE (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
GROWLING,
GRATING OR
SCRAPING NOISES1. Drive Plate Broken. 1. Replace.
2. Torque Converter Bolts Hitting
Dust Shield.2. Dust shield bent. Replace or repair.
3. Planetary Gear Set Broken/
Seized.3. Check for debris in oil pan and repair as
required.
4. Overrunning Clutch Worn/
Broken.4. Inspect and check for debris in oil pan. Repair
as required.
5. Oil Pump Components
Scored/Binding.5. Remove, inspect and repair as required.
6. Output Shaft Bearing or Bushing
Damaged.6. Remove, inspect and repair as required.
7. Clutch Operation Faulty. 7. Perform air pressure check and repair as
required.
8. Front and Rear Bands
Mis-adjusted.8. Adjust bands.
DRAGS OR LOCKS
UP1. Fluid Level Low. 1. Check and adjust level.
2. Clutch Dragging/Failed 2. Air pressure check clutch operation and repair
as required.
3. Front or Rear Band Mis-
adjusted.3. Adjust bands.
4. Case Leaks Internally. 4. Check for leakage between passages in case.
5. Servo Band or Linkage
Malfunction.5. Air pressure check servo operation and repair
as required.
6. Overrunning Clutch Worn. 6. Remove and inspect clutch. Repair as required.
7. Planetary Gears Broken. 7. Remove, inspect and repair as required (look
for debris in oil pan).
8. Converter Clutch Dragging. 8. Check for plugged cooler. Perform flow check.
Inspect pump for excessive side clearance.
Replace pump as required.
NO 4-3 DOWNSHIFT 1. Circuit Wiring and/or Connectors
Shorted.1.
Test wiring and connectors with test lamp and
volt/ohmmeter. Repair wiring as necessary. Replace
connectors and/or harnesses as required.
2. PCM Malfunction. 2. Check PCM operation with DRBTscan tool.
Replace PCM only if faulty.
3. TPS Malfunction 3. Check TPS with DRBTscan tool at PCM.
4. Lockup Solenoid Not Venting. 4. Remove valve body and replace solenoid
assembly if plugged or shorted.
5. Overdrive Solenoid Not Venting. 5. Remove valve body and replace solenoid if
plugged or shorted.
6. Valve Body Valve Sticking. 6. Repair stuck 3-4 shift valve or lockup timing
valve.
NO 4-3 DOWNSHIFT
WHEN CONTROL
SWITCH IS TURNED
OFF1. Control Switch Open/Shorted. 1. Test and replace switch if faulty.
2. Overdrive Solenoid Connector
Shorted.2. Test solenoids and replace if seized or shorted.
3. PCM Malfunction. 3.
Test with DRBTscan tool. Replace PCM if faulty.
4. Valve Body Stuck Valves. 4.Repair stuck 3-4, lockup or lockup timing valve.
21 - 22 AUTOMATIC TRANSMISSION - 42REWJ
AUTOMATIC TRANSMISSION - 42RE (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
CLUNK NOISE FROM
DRIVELINE ON
CLOSED THROTTLE
4-3 DOWNSHIFT1. Transmission Fluid Low. 1. Add Fluid.
2. Throttle Cable Mis-adjusted. 2. Adjust cable.
3. Overdrive Clutch Select Spacer
Wrong Spacer.3. Replace overdrive piston thrust plate spacer.
3-4 UPSHIFT
OCCURS
IMMEDIATELY AFTER
2-3 SHIFT1. Overdrive Solenoid Connector or
Wiring Shorted.1.
Test connector and wiring for loose connections,
shorts or ground and repair as needed.
2. TPS Malfunction. 2. Test TPS and replace as necessary. Check with
DRBTscan tool.
3. PCM Malfunction. 3. Test PCM with DRBTscan tool and replace
controller if faulty.
4. Overdrive Solenoid Malfunction. 4. Replace solenoid.
5. Valve Body Malfunction. 5. Remove, disassemble, clean and inspect valve
body components. Make sure all valves and plugs
slide freely in bores. Polish valves with crocus
cloth if needed.
WHINE/NOISE
RELATED TO ENGINE
SPEED1. Fluid Level Low. 1. Add fluid and check for leaks.
2. Shift Cable Incorrect Routing. 2. Check shift cable for correct routing. Should not
touch engine or bell housing.
NO 3-4 UPSHIFT 1. O/D Switch In OFF Position. 1. Turn control switch to ON position.
2. Overdrive Circuit Fuse Blown. 2. Replace fuse. Determine why fuse failed and
repair as necessary (i.e., shorts or grounds in
circuit).
3. O/D Switch Wire Shorted/Open
Cut.3. Check wires/connections with 12V test lamp
and voltmeter. Repair damaged or loose
wire/connection as necessary.
4. Distance or Coolant Sensor
Malfunction.4. Check with DRBTscan tool and repair or
replace as necessary.
5. TPS Malfunction. 5. Check with DRBTscan tool and replace if
necessary.
6. Neutral Sense to PCM Wire
Shorted/Cut.6. Test switch/sensor as described in service
section and replace if necessary. Engine no start.
7. PCM Malfunction. 7. Check with DRBTscan tool and replace if
necessary.
8. Overdrive Solenoid Shorted/
Open.8. Replace solenoid if shorted or open and repair
loose or damaged wires (DRBTscan tool).
9. Solenoid Feed Orifice in Valve
Body Blocked.9. Remove, disassemble, and clean valve body
thoroughly. Check feed orifice.
10. Overdrive Clutch Failed. 10. Disassemble overdrive and repair as needed.
11. Hydraulic Pressure Low. 11. Pressure test transmission to determine
cause.
12. Valve Body Valve Stuck. 12. Repair stuck 3-4 shift valve, 3-4 timing valve.
13. O/D Piston Incorrect Spacer. 13. Remove unit, check end play and install
correct spacer.
14. Overdrive Piston Seal Failure. 14. Replace both seals.
15. O/D Check Valve/Orifice Failed. 15. Check for free movement and secure
assembly (in piston retainer). Check ball bleed
orifice.
WJAUTOMATIC TRANSMISSION - 42RE 21 - 23
AUTOMATIC TRANSMISSION - 42RE (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
OIL LEAKS. 1. Fluid Lines and Fittings
Loose/Leaks/Damaged.1. Tighten fittings. If leaks persist, replace fittings
and lines if necessary.
2. Fill Tube (where tube enters
case) Leaks/Damaged.2. Replace tube seal. Inspect tube for cracks in fill
tube.
3. Pressure Port Plug Loose
Loose/Damaged.3. Tighten to correct torque. Replace plug or
reseal if leak persists.
4. Pan Gasket Leaks. 4. Tighten pan screws (150 in. lbs.). If leaks
persist, replace gasket.
5. Valve Body Manual Lever Shaft
Seal Leaks/Worn.5. Replace shaft seal.
6. Rear Bearing Access Plate
Leaks.6. Replace gasket. Tighten screws.
7. Gasket Damaged or Bolts are
Loose.7. Replace bolts or gasket or tighten both.
8. Adapter/Extension Gasket
Damaged Leaks/Damaged.8. Replace gasket.
9. Park/Neutral Switch, or
Transmission Range Sensor
Leaks/Damaged.9. Replace switch and gasket.
10. Converter Housing Area Leaks. 10. Check for leaks at seal caused by worn seal
or burr on converter hub (cutting seal), worn
bushing, missing oil return, oil in front pump
housing or hole plugged. Check for leaks past
O-ring seal on pump or past pump-to-case bolts;
pump housing porous, oil coming out vent due to
overfill or leak past front band shaft access plug.
11. Pump Seal Leaks/Worn/
Damaged.11. Replace seal.
12. Torque Converter Weld
Leak/Cracked Hub.12. Replace converter.
13. Case Porosity Leaks. 13. Replace case.
NOISY OPERATION
IN FOURTH GEAR
ONLY1. Overdrive Clutch Discs, Plates
or Snap Rings Damaged.1. Remove unit and rebuild clutch pack.
2. Overdrive Piston or Planetary
Thrust Bearing Damaged.2. Remove and disassemble unit. Replace either
thrust bearing if damaged.
3. Output Shaft Bearings
Scored/Damaged.3. Remove and disassemble unit. Replace either
bearing if damaged.
4. Planetary Gears Worn/Chipped. 4. Remove and overhaul overdrive unit.
5. Overdrive Unit Overrunning
Clutch Rollers Worn/Scored.5. Remove and overhaul overdrive unit.
STANDARD PROCEDURE - ALUMINUM
THREAD REPAIR
Damaged or worn threads in the aluminum trans-
mission case and valve body can be repaired by the
use of Heli-CoilsŸ, or equivalent. This repair con-
sists of drilling out the worn-out damaged threads.
Then tap the hole with a special Heli-CoilŸ tap, or
equivalent, and installing a Heli-CoilŸ insert, orequivalent, into the hole. This brings the hole back to
its original thread size.
Heli-CoilŸ, or equivalent, tools and inserts are
readily available from most automotive parts suppli-
ers.
21 - 26 AUTOMATIC TRANSMISSION - 42REWJ
AUTOMATIC TRANSMISSION - 42RE (Continued)

(10) Remove valve body assembly. Push valve body
harness connector out of case. Then work park rod
and valve body out of case (Fig. 24).
(11) Remove accumulator piston and inner and
outer springs (Fig. 25).
(12) Remove pump oil seal with suitable pry tool
or slide-hammer mounted screw.
(13) Loosen front band adjusting screw locknut 4-5
turns. Then tighten band adjusting screw until bandis tight around front clutch retainer. This prevents
front/rear clutches from coming out with pump and
possibly damaging clutch or pump components.
(14) Remove oil pump bolts.
(15) Thread bolts of Slide Hammer Tools C-3752
into threaded holes in pump body flange (Fig. 26).
(16) Bump slide hammer weights outward to
remove pump and reaction shaft support assembly
from case (Fig. 26).
(17) Loosen front band adjusting screw until band
is completely loose.
Fig. 22 Oil Filter Removal
1 - OIL FILTER
2 - VALVE BODY
3 - FILTER SCREWS (2)
Fig. 23 Valve Body Bolt Locations
1 - VALVE BODY BOLTS
2 - VALVE BODY BOLTS
Fig. 24 Valve Body Removal
1 - GOVERNOR PRESSURE SENSOR
2 - VALVE BODY
3 - PARK ROD
4 - ACCUMULATOR PISTON
5 - GOVERNOR PRESSURE SOLENOID
Fig. 25 Accumulator Piston And Springs
1 - ACCUMULATOR PISTON
2 - OUTER SPRING
3 - INNER SPRING
21 - 30 AUTOMATIC TRANSMISSION - 42REWJ
AUTOMATIC TRANSMISSION - 42RE (Continued)