1998 ISUZU TROOPER oil pressure

7A±1 AUTOMATIC TRANSMISSION (4L30±E)
TRANSMISSION
AUTOMATIC TRANSMISSION (4L30±E)
CONTENTS
Service Precaution 7A±3. . . . . . . . . . . . . . . . . . . . . .
Construction 7A±3. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Range Reference Chart 7A±4. . . . . . . . . . . . . . . . . .
Normal Operation Of 1998 4L30±E
Transmission 7A±5. . . . . . . . . . . . . . . . . . . . . . . . . . .
Diagnosis 7A±5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Driver Information 7A±5. . . . . . . . . . . . . . . . . . . . . . .
General Diagnosis Procedure 7A±8. . . . . . . . . . . . .
Preliminary Inspection Chart 7A±9. . . . . . . . . . . . . .
Checking Transmission Fluid Level and
Condition 7A±10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Test Driving 7A±11. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mechanical / Hydraulic Diagnosis Check Trans
Indicator Chart 7A±12. . . . . . . . . . . . . . . . . . . . . . . . . .
Mechanical / Hydraulic Diagnosis Symptoms
Index 7A±13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stall Test 7A±23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Line Pressure Test 7A±23. . . . . . . . . . . . . . . . . . . . . .
Shift Speed Chart 7A±24. . . . . . . . . . . . . . . . . . . . . . .
Lockup Speed Chart 7A±26. . . . . . . . . . . . . . . . . . . . .
Changing Transmission Fluid 7A±27. . . . . . . . . . . . .
Selector Lever 7A±27. . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection 7A±27. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal 7A±28. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 7A±28. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mode Switch 7A±29. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal 7A±29. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 7A±29. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transmission (With Transfer Case) 7A±31. . . . . . . .
Transmission And Associated Parts 7A±31. . . . . .
Removal 7A±31. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 7A±33. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Solenoid (Main Case Valve Body) 7A±36. . . . . . . . .
Removal 7A±36. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 7A±36. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Solenoid (Adapter Case Valve Body) 7A±37. . . . . . .
Removal 7A±37. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 7A±37. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve Body Assembly (Main Case) 7A±38. . . . . . . .
Removal 7A±38. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 7A±38. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve Body Assembly (Adapter Case) 7A±40. . . . . .
Removal 7A±40. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 7A±40. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Powertrain Control Module (PCM) 7A±40. . . . . . . . . Removal 7A±40. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 7A±40. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Speed Sensor (Extension Housing) 7A±41. . . . . . . .
Removal 7A±41. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 7A±41. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transmission Oil Temperature Sensor
(Adapter Case) 7A±41. . . . . . . . . . . . . . . . . . . . . . . . .
Removal 7A±41. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 7A±42. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Front Oil Seal (Converter Housing) 7A±42. . . . . . . .
Removal 7A±42. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 7A±42. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear Oil Seal (Extension Housing) 7A±43. . . . . . . . .
Removal 7A±43. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 7A±43. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transmission (4L30±E) 7A±43. . . . . . . . . . . . . . . . . .
Disassembly 7A±43. . . . . . . . . . . . . . . . . . . . . . . . . .
Reassembly 7A±47. . . . . . . . . . . . . . . . . . . . . . . . . .
Converter Housing And Oil Pump Assembly 7A±57
Disassembled View 7A±57. . . . . . . . . . . . . . . . . . . .
Disassembly 7A±57. . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection And Repair 7A±57. . . . . . . . . . . . . . . . . .
Reassembly 7A±57. . . . . . . . . . . . . . . . . . . . . . . . . .
Oil Pump 7A±58. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disassembled View 7A±58. . . . . . . . . . . . . . . . . . . .
Disassembly 7A±58. . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection And Repair 7A±58. . . . . . . . . . . . . . . . . .
Reassembly 7A±58. . . . . . . . . . . . . . . . . . . . . . . . . .
Main Case Valve Body 7A±59. . . . . . . . . . . . . . . . . . .
Disassembled View 7A±59. . . . . . . . . . . . . . . . . . . .
Disassembly 7A±59. . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection And Repair 7A±60. . . . . . . . . . . . . . . . . .
Reassembly 7A±60. . . . . . . . . . . . . . . . . . . . . . . . . .
Adapter Case Valve Body 7A±61. . . . . . . . . . . . . . . .
Disassembled View 7A±61. . . . . . . . . . . . . . . . . . . .
Disassembly 7A±61. . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection And Repair 7A±61. . . . . . . . . . . . . . . . . .
Reassembly 7A±61. . . . . . . . . . . . . . . . . . . . . . . . . .
Third Clutch And Sprag Unit 7A±63. . . . . . . . . . . . . .
Disassembled View 7A±63. . . . . . . . . . . . . . . . . . . .
Disassembly 7A±63. . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection And Repair 7A±64. . . . . . . . . . . . . . . . . .
Reassembly 7A±64. . . . . . . . . . . . . . . . . . . . . . . . . .
Third Clutch 7A±65. . . . . . . . . . . . . . . . . . . . . . . . . . . .

7A±5 AUTOMATIC TRANSMISSION (4L30±E)
Normal Operation Of 1998 4L30±E
Transmission
Torque Converter Clutch (TCC)
Application Conditions:
The TCC is normally applied in 2nd, 3rd and 4th gears
only when all of the following conditions exist:
Ð The engine coolant temperature is above 70
C
(158
F).
Ð The brake pedal is released.
Ð The shift pattern requests TCC apply.
Moreover, TCC is always applied in 2nd, 3rd and 4th
gears when the transmission oil temperature is above
135
C (275
F).
This mode should be canceled at 125
C (257
F).
ATF Warning Lamp
The ATF warning lamp will be constantly on (not flashing)
if the transmission oil temperature is above 140
C
(284
F).
The ATF warning lamp goes off again when the
transmission oil temperature is below 130
C (266
F).
Special Shift Pattern When The Engine Is
Cold:
A special shift pattern is activated when the engine
coolant temperature is below 70
C (158
F). (3±4 shifts,
for example, are delayed for small throttle openings and
will occur a few MPH higher.)
Diagnosis
Introduction
The systematic troubleshooting information covered by
this Section offers a practical and systematic approach to
diagnosing 4L30±E transmission, using information that
can be obtained from road tests, electrical diagnosis, oil
pressure checks or noise evaluation.
The key to correcting a complaint is to make use of all of
the available symptoms and logically letting them direct
you to the cause.
When dealing with automatic transmission complaints, it
is best to gather as many symptoms as possible before
making the decision to remove the transmission from the
vehicle.
Frequently, the correction of the complaint does not
require removal of the transmission from the vehicle.
Driver Information
To analyze the problem fill out a complete description of
the owner's complaint.
Please draw a circle around the right information and
complete the following form. (The next page is an
example of a completed form). You can draw a circle
around many numbers if you are not sure.

7A±18
AUTOMATIC TRANSMISSION (4L30±E)
Chart 9c: Coastdown Harsh Shift Or Clunk At 3±2 Downshift
StepActionYe sNo
1Check line pressure. Refer to Line Pressure Test in this section.
Was line pressure normal?
Go to Step 2
Use Chart 15b:
Possible Causes
of High Line
Pressure in this
section
2Does DTC P1850 set?
Diagnose P1850
first
Replace band
apply solenoid
(PWM) (323)
Chart 10: Intermittent 4TH TO 2ND Gear Downshift At Steady Speed
StepActionYe sNo
1Check for consistent speed sensor reading with scan tool.
Was the reading correct?Replace mode
switch for
intermittent
contact.
Go to Step 2
21. Check for wiring harness damage or short to ground. If OK, go
to (2).
2. Check transmission speed sensor connections. If OK, go to
(3).
3. Replace transmission speed sensor.
Was the replacement complete?
Ð
Replace speed
sensor.
Chart 11: Engine Flare At Shifting During Turning Only (Usually With Warm Engine)
StepActionYe sNo
1Check for oil leaks at transmission.
Was the problem found?Replace
transmission oil
filter and gasket
Ð
Chart 12: Engine Flare During 1±2 Or 2±3 Shift
StepActionYe sNo
1Check line pressure. Refer to Line Pressure Test in this section.
Was line pressure normal?
Go to Step 2
Use Chart 15a:
Possible Causes
of Low Line
Pressure in this
section
21. Check for a stuck 1±2 accumulator valve (320).
2. Check for servo piston (106) leaks.
3. Check for a stuck band apply solenoid (323).
Was line pressure normal?
Repair or replaceÐ

7A±20
AUTOMATIC TRANSMISSION (4L30±E)
Chart 15a: Possible Causes of Low Line Pressure
StepActionYe sNo
1Check oil level.
Was the problem found?
Fill with ATFGo to Step 2
2Check for defective throttle position sensor.
Was the problem found?Replace throttle
position sensor
Go to Step 3
3Check for plugged, loose, or damaged oil filter (79).
Was the problem found?Inspect oil filter,
tighten bolts or
replace oil filter
(79)
Go to Step 4
4Check for a stuck force motor plunger (404). (Adapter case valve
body)
Was the problem found?Replace force
motor plunger
(404)
Go to Step 5
5Check for a stuck feed limit valve (412). (Adapter case valve body)
Was the problem found?Replace feed limit
valve (412)
Go to Step 6
6Check for loose converter bolts (4 & 5).
Was the problem found?Tighten converter
bolts (4 & 5)
Go to Step 7
7Check for a stuck pressure regulator valve (208). (Oil pump)
Was the problem found?Replace pressure
regulator valve
(208)
Go to Step 8
8Check for a stuck boost valve (205).(Oil pump)
Was the problem found?Replace boost
valve (205)
Go to Step 9
9Check for blocked intermediate oil passages to pressure
regulator valve. (Oil pump)
Was the problem found?
Replace oil pumpGo to Step 10
10Check for defective oil pump (9, 201, 202 & 209).
Was the problem found?
Replace oil pumpGo to Step 11
11Check for internal leaks.
± Check balls missing or out of location in valve bodies
± Seals cut or damaged
± Gaskets defective, etc.
Was the problem found?Install balls, or
correct ball
location
Replace seals
Replace gaskets
Ð

7A±21 AUTOMATIC TRANSMISSION (4L30±E)
Chart 15b: Possible Causes Of High Line Pressure
NOTE: If transmission is operating in backup mode, high
line pressure will be present.
Step
ActionYe sNo
1Check for defective throttle position sensor.
Was the problem found?Replace throttle
position sensor.
Go to Step 2.
2Check for a stuck force motor plunger (404). (Open
circuit/intermittent) (Adapter case valve body)
Was the problem found?Replace force
motor plunger
(404)
Go to Step 3
3Check for a stuck feed limit valve (412). (Adapter case valve body)
Was the problem found?Replace force
motor plunger
(412)
Go to Step 4
4Check converter bolts (4 & 5).
Was the problem found?Tighten converter
bolts (4 & 5)
Go to Step 5
5Check for a stuck pressure regulator valve (208). (Oil pump)
Was the problem found?Replace pressure
regulator valve
(208)
Go to Step 6
6Check for a stuck boost valve (205). (Oil pump)
Was the problem found?Replace boost
valve (205)
Go to Step 7
7Check for internal leaks.
± Check balls missing or out of location in valve bodies
± Seals cut or missing
± Gaskets defective, etc.
Was the problem found?Install balls, or
correct ball
location
Replace seals
Replace gaskets
Ð

7A±22
AUTOMATIC TRANSMISSION (4L30±E)
Chart 16: Possible Causes Of
Transmission Fluid Leaks
Before attempting to correct an oil leak, the actual source
of the leak must be determined. In many cases, the
source of the leak may be difficult to determine due to
ªwind flowº around the engine and transmission.
The suspected area should be wiped clean before in-
specting for the source of the leak.Oil leaks around the engine and transmission are gener-
ally carried toward the rear of the vehicle by the air
stream. In determining the source of an leak, the following
two checks should be made:
1. With the engine running, check for external line
pressure leaks.
2. With the engine off, check for oil leaks due to the
raised oil level caused by drainback of converter oil
into the transmission.
Possible Causes Of Fluid Leaks Due To Sealing Malfunction
240RS002
Legend
(1) Electrical Connector (Main Case) Seal
(2) Transmission Vent (Breather)
(3) Speed Sensor O±Ring
(4) Extension (Adapter) Lip Seal
(5) Extension (Adapter) to Main Case Gasket
(6) Oil Drain Plug Gasket
(7) Oil Pan Gasket (Main Case)
(8) Selector Shaft Seal(9) Oil Cooler Connectors (2)
(10) Oil Pan Gasket (Adapter Case)
(11) Converter housing attaching bolts not correctly
torqued
(12) Converter Housing Lip Seal
(13) Line Pressure Tap Plug
(14) Electrical Connector (Adapter Case) Seal
(15) Adapter Case Seal Rings (2)

7A±23 AUTOMATIC TRANSMISSION (4L30±E)
Stall Test
The stall test allows you to check the transmission for
internal abrasion and the one way clutch for slippage.
Torque converter performance can also be evaluated.
The stall test results together with the road test results will
identify transmission components requiring servicing or
adjustment.
Stall Test Procedure:
1. Check the level of the engine coolant, the engine oil,
and the automatic transmission fluid. Replenish if
necessary.
2. Block the wheels and set the parking brake.
3. Connect a tachometer to the engine.
4. Start the engine and allow it to idle until the engine
coolant temperature reaches 70 ± 80
C (158 ±
176
F).
5. Hold the brake pedal down as far as it will go.
6. Place the selector in the ªDº range.
7. Gradually push the accelerator pedal to the floor.
The throttle valve will be fully open.
Note the engine speed at which the tachometer
needle stabilizes.
Stall Speed : 2,100 +150 rpm
NOTE: Do not continuously run this test longer than 5
seconds.
8. Release the accelerator pedal.
9. Place the selector in the ªNº range.
10. Run the engine at 1,200 rpm for one minute.
This will cool the transmission fluid.
11. Repeat Steps 7 ± 10 for the ª3º, ª2º, ªLº and ªRº
ranges.
Line Pressure Test
The line pressure test checks oil pump and control valve
pressure regulator valve function. It will also detect oil
leakage.
Line Pressure Test Procedure:
1. Check the level of the engine coolant, the engine oil,
and the automatic transmission fluid.
Replenish if required.
2. Block the wheels and set the parking brake.
3. Remove the pressure detection plug at the left side of
the transmission case.
Set 5±8840±0004±0 pressure gauge and adapter to
the pressure detection plug hole.
241RS001
4. Start the engine and allow it to idle until the engine
coolant temperature reaches 70 ± 80
C (158 ±
176
F).
5. Hold the brake pedal down as far as it will go.
6. Place the selector in the ªDº range.
7. Note the pressure gauge reading with the engine
idling.
8. Gradually push the accelerator pedal to the floor. The
throttle valve will be fully open.
Note the pressure gauge reading with the accelerator
pedal fully depressed.
NOTE: Do not continuously run this test longer than 5
seconds.
9. Release the accelerator pedal.
10. Place the selector in the ªNº range.
11. Run the engine at 1,200 rpm for one minute.
This will cool the transmission fluid.
12. Repeat Steps 7 ± 11 for the ª3º, ª2º, ªLº, and ªRº
ranges.
13. Install a pressure detection plug to the transmission
case, applying recommended thread locking agent
(LOCTITE 242) or its equivalent to thread of plug.
Make sure that thread is cleaned before applying
locking agents.
14. Tighten the pressure detection plug to the specified
torque.
Torque: 9 ± 14N´m (0.9 ± 1.4 kg´m/7 ± 10 lb ft)

7A±47 AUTOMATIC TRANSMISSION (4L30±E)
36. Separate second (40) and third clutch (41)
assemblies.
37. Remove thrust washer (42).
38. Remove reverse clutch plates (43 and 44) and
reverse clutch pressure plate (45).
39. Remove bearing (46) and washer (47).
40. Remove planetary carrier assembly (48).
41. Remove thrust bearing (49).
42. Remove reaction sun gear (50)
43. Remove needle bearing (51).
44. Remove brake drum (52).
45. Remove brake band (53).
46. Remove thrust bearing (54).
242RS003
47. Rotate case to horizontal position, valve body side
facing up.

Remove spring pin (55), using cutting pliers, then
remove parking lock and selector lever assembly
(56).NOTE: Insert wire in the center of the spring pin to
prevent it from collapsing during removal. Be aware of pin
height. Protect machined face of main case.
48. Remove parking lock and range selector lever 17 mm
nut (57).
49. Remove parking lock and range selector lever (56),
and actuator assembly.
50. Remove selector shaft (58).
NOTE: Inspect the shaft for burrs before removing to
prevent damaging seal. If necessary, remove burrs by
lightly sanding with an oilstone.
249RS004
Reassembly
1. Inspect selector shaft seal, and replace it if
necessary.
NOTE: Use a seal installer when replacing the seal.

Install selector shaft.
NOTE: Spring pin groove must be positioned inside the
case.
2. Install spring pin. Be sure the selector shaft can move
freely. Do not push the pin flush with the case surface.
Leave enough height for removal.
3. Install actuator assembly (1).
4. Install parking lock and range selector lever (2) and
new 17 mm nut. Tighten the nut to the specified
torque.
Torque: 22 Nwm (2.2 kg´m/16 lb ft)