1998 ISUZU TROOPER transmission oil

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
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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±27 AUTOMATIC TRANSMISSION (4L30±E)
Changing Transmission Fluid
There is no need to change the transmission fluid unless
the transmission is used under one or more of the
following heavy duty conditions.
A. Repeated short trips
B. Driving on rough roads
C. Driving on dusty roads
D. Towing a trailer
If the vehicle is used under these conditions, change the
fluid every 20,000 miles (32,000 km.)
More over, the remaining life percentage of ATF can be
estimated by using Tech 2 as an auxiliary tool to judge the
right time for ATF replacement.
The remaining life percentage is calculated from ATF'S
heat history. When it is close to 0%, ATF replacement is
recommended.
1. Place a large drain pan under the oil pan.
2. Remove the transmission oil drain screw (2) and drain
fluid.
3. Tighten drain screw (2).
Torque: 38 Nwm (3.9 kg´m/28 lb ft)
4. Remove the transmission overfill screw (1) and fill
transmission through overfill screw opening, using
DEXRON)±III ATF.
NOTE: Add transmission fluid until it flows out over the
overfill screw opening.
5. Let engine idle until a fluid temperature between 32
C
(90
F) and 57
C (135
F) is reached.6. Add transmission fluid until it flows out over the overfill
screw opening, then close the overfill screw (1).
Torque: 38 Nwm (3.9 kg´m/28 lb ft)
NOTE: To prevent fluid leaks, the overfill screw and oil
drain screws gasket must be replaced each time these
screws are removed.
NOTE: C h e c k t r a n s mission fluid temperature with
service scan tool.
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Selector Lever
Inspection
1. Make sure that when the shifter control lever is shifted
from ªPº to ªLº, a ªclickingº can be felt at each shift
position. Make sure that the gear corresponds to that
of the position plate indicator.
2. Check to see if the shifter lever can be shifted as
shown in illustration.
C07RW009

7A±28
AUTOMATIC TRANSMISSION (4L30±E)
Removal
1. Disconnect battery ground cable.
2. Remove transfer control lever knob.
3. Remove front console.

Disconnect wiring harness connectors from front
console.
4. Disconnect shift lock cable (1) from the selector lever
assembly side.
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5. Disconnect shift control rod (2) from the selector lever
assembly side.
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6. Disconnect wiring harness connectors from the
selector lever assembly.
7. Remove selector lever assembly.
Installation
To install, follow the removal steps in the reverse order,
noting the following points:
Adjustment of select lever and control rod
1. Place the vehicle on a level surface.NOTE: If the vehicle is not on level surface, the shift
select cable set positions will vary with the movement of
engine. To prevent possible misadjustment of the cable,
the vehicle must be placed on a level surface.
2. Install the shift control rod (1) to the transmission
select lever (2), and then place the lever in the ªNº
position.
3. Set select lever in the ªNº position.
4. Push select lever forward (ªRº position side) and
secure it (using a rubber band (3), etc.) so that the pin
comes into contact with the wall of the detent plate.
5. Install the shift control rod (1) to the selector lever arm
(4).
Torque: 32 Nwm (3.3 kg´m/24 lb ft)
NOTE: Do not apply oil to the threaded portions.
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6. After adjustment, make sure that the selector lever
operates normally, and that each selector position is
properly indicated. (The red mark shows through the
window.)
Adjustment of shift lock cable
1. Set ignition key in ªLOCKº position and selector lever
in ªPº position.
2. Adjust cable screw cap on selector lever side to
provide a gap (slack for cable) of 1 ± 2 mm between
rod on steering lock side and stopper.
Adjust cap as follows:
a. Pull screw cap (1) in arrow direction to remove
inner cable slack.
b. With cable kept as (a), adjust gap between nut (2)
and bracket to 5 mm (0.2 in).
c. Lock inner cable by turning nut (3) while holding nut
(2) in place.
Torque : 3.7 Nwm (38 kg´cm/33 lb in)
NOTE: Clean the cable threads, and do not apply oil to
them.

7A±31 AUTOMATIC TRANSMISSION (4L30±E)
Transmission (With Transfer Case)
Transmission And Associated Parts
240RW027
Legend
(1) Transfer Control Lever Knob
(2) Front Console
(3) Selector Lever Assembly
(4) Transfer Control Lever
(5) Transfer and Exhaust Protector
(6) Rear Propeller Shaft
(7) Front Propeller Shaft
(8) Harness Protector
(9) Rear Mount Nut(10) Third Crossmember
(11) Exhaust Pipe
(12) Transmission Oil Cooler Pipe
(13) Starter
(14) Transmission Harness Connector
(15) Under Cover
(16) Torque Converter Bolt
(17) Engine Transmission Bolt
(18) Transmission Assembly
Removal
NOTE: Before remove transmission and transfer
assembly from vehicle, change the tansfer mode to 2WD
using push button on dash panel.1. Remove engine hood.
2. Disconnect battery ground cable.
3. Remove transfer control lever knob (1) and
disconnect wiring harness connectors, then remove
front console (2).

7A±32
AUTOMATIC TRANSMISSION (4L30±E)
4. Disconnect shift lock cable from the selector lever
assembly side.
256RW012
5. Disconnect wiring harness connectors.
6. Disconnect shift control rod from the selector lever
assembly side.
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7. Remove selector lever assembly (3).
8. Remove transfer control lever (4).
9. Remove transfer and exhaust protector (5).
10. Remove rear propeller shaft (6).
11. Remove front propeller shaft (7).
12. Remove harness protector (8).
13. Support transfer case with a jack and remove two rear
mount nuts (9) from the 3rd crossmember side.
14. Remove eight third crossmember bolts and third
crossmember (10).
15. Disconnect one oxygen sensor connector from the
transmission harness.
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16. Remove exhaust pipe (11).
17. Disconnect transmission oil cooler pipe (12) from A/T
side.
18. Remove oil pipe clamp from torque converter
housing bracket.
253RW001
19. Loosen oil pipe clamp bolt at the engine mount side.
20. Remove starter (13).
21. Disconnect fuel pipe clamp bracket from
transmission side.
22. Disconnect transmission harness connectors (14)
from transmission, and transfer.
23. Remove flywheel under covers (3 pieces) (15) from
transmission case.
24. Lower the front of the transmission a little, then
remove flywheel torque converter fixing bolts (6
pieces) (16) by turning crankshaft.
25. Support the transmission with a transmission jack,
and hoist engine with a chain block.
26. Remove engine transmission fixing bolts (17).