2004 ISUZU TF SERIES transmission fluid

ON-VEHICLE SERVICE (AW30–40LE) 7A3-1
TRANSMISSION
ON-VEHICLE SERVICE (AW30–40LE)
CONTENTS

Service Precaution .................................................
7A3-2
Location of Clutch, Brake, One-Way Clutch
and Solenoid ........................................................
7A3-3
Operation of Clutch, Brake and One-Way
Clutch ....................................................................
7A3-4
Trnasmission Indentification ..............................
7A3-4
Speed Change and Lock-Up Pattern ...............
7A3-5
Overdrive and Lock-Up Operating
Conditions ............................................................
7A3-5
Diagnosis .................................................................
7A3-6
Basic Troubleshooting ........................................
7A3-6
Manual Shifting Test ...........................................
7A3-12
Stall Test ..............................................................
7A3-12
Time Lag Test .....................................................
7A3-13
Hydraulic Test ......................................................
7A3-14
Road Test .............................................................
7A3-15
Shift Pont Chart and Lock-Up Point Chart ..........
7A3-19
Shift Pont Chart ...................................................
7A3-19
Lock-Up Point Chart ...........................................
7A3-20
Transmission Fluid Level and Condition .............
7A3-21
Inspection .............................................................
7A3-21
ATF Replacement ..................................................
7A3-22
Inspection .............................................................
7A3-22
Neutral Start Switch (Mode Switch) .....................
7A3-23
Inspection .............................................................
7A3-23
Removal ...............................................................
7A3-23
Installation ............................................................
7A3-23
Brake Signal ............................................................
7A3-24
Inspection .............................................................
7A3-24
Input and Output Revolution Sensor ....................
7A3-25
Inspection .............................................................
7A3-25
Pattern Select Switch .............................................
7A3-25
Inspection .............................................................
7A3-25
Solenoid ...................................................................
7A3-26
Inspection .............................................................
7A3-26

ATF Temperature Sensor ......................................
7A3-27
Inspection .............................................................
7A3-27
Select Lever ....................................................... 7A3-28 Remove or Disconnect .......................................
7A3-28
Install or Connect .................................................
7A3-29
Shift Cable ......................................................... 7A3-31
Remove or Disconnect .......................................
7A3-31
Install or Connect .................................................
7A3-32
Torque specifications ..........................................
7A3-33
Transmission Control Module (TCM) ...................
7A3-34
Removal ................................................................
7A3-34
Installation .............................................................
7A3-34
Shift Solenoid and Lock-Up Solenoid ...................
7A3-35
Removal ................................................................
7A3-35
Installation .............................................................
7A3-36
Valve Body Assembly and Pressure Control Solenoid .................................................
7A3-37
Removal ................................................................
7A3-37
Installation .............................................................
7A3-39
Rear Oil Seal (Adapter Housing, 4

4) .................
7A3-40
Removal ................................................................
7A3-40
Installation .............................................................
7A3-40
Rear Oil Seal (Extension Housing, 4
2) ..............
7A3-41
Removal ................................................................
7A3-41
Installation .............................................................
7A3-41
Transmission Assembly .........................................
7A3-42
Transmission and Associated Parts .................
7A3-42
Removal ................................................................
7A3-43
Installation .............................................................
7A3-46
Major Components ..............................................
7A3-50

7A3-12 ON-VEHICLE SERVICE (AW30 –40LE)

Manual Shifting Test
NOTE: With this test, it can be determined whether the
trouble lies within the electrical circuit or is a mechanical
problem in the transmission.
1. Disconnect TCM connector
Inspect manual driving operation
2. Inspect manual driving operation
Check that the shift and gear positions correspond
with the table.
If the “L", “2", “3" and “D" range gear positions are
difficult to distinguish, do perform the following road
test.
While driving, shift through the “L", “2", “3" and “D"
ranges. Check that the gear change corresponds to
the gear position.
If any abnormality is found in the above test, do
perform the stall, time lag or gear change tests.



RUW37ASH004101
3. Connect TCM connector
With the engine off, connect the TCM connector.


Stall Test



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The object of this test is to check the overall
performance of the transmission and engine b
y
measuring the maximum engine speeds at the “D" and
“ R" ranges.
NOTE:
1. Perform the test at normal operation fluid
temperature (50 – 80 
C or 122 – 176 
F).
2. Do not continuously run this test longer than 5 seconds.

7A3-14 ON-VEHICLE SERVICE (AW30 –40LE)

Measure Time Lag
1. Fully apply the parking brake.
2. Start the engine. Check idling speed (A/C OFF).
3. Shift the shift lever from “N" to “D" range. Using a
stopwatch, measure the time it takes from shifting
the lever until the shock is felt.
Time lag: Less than 0.7 seconds
4. In same manner, measure the time lag for “N"


“R".
Time lag: Less than 1.2 seconds
Evaluation
1. If “N" 
“ D" time lag is longer than specified:

Line pressure too low
 Forward clutch malfunction
 No.2 one-way clutch not operating properly
2. If “N" 
“ R" time lag is longer than specified:

Line pressure too low
 Direct clutch malfunction
 No.3 brake malfunction
3. If both time lag is longer than specified:

Line pressure too low

Hydraulic Test



RUW37ALH000201
Preparation

1. Warm up the transmission fluid.
2. Remove the transmission case test plug and mount the hydraulic pressure gauge.
Oil pressure gauge: J –29770 –A
NOTE: Perform the test at normal operation fluid
temperature (50 – 80 
C or 122 – 176 
F).

ON-VEHICLE SERVICE (AW30 –40LE) 7A3-21

Transmission Fluid Level and Condition
Inspection
Park vehicle on level ground and set parking brake.
With the engine idling, move the shift lever through all
positions from “P" to “L", then return to position “P".
Check to see if the level of fluid comes to “HOT" range
of about 80 
 

C (176 
 

F) on the dipstick gauge.
If the level of fluid is too low, replenish to bring it to
maximum level in “HOT" range.
Inspection of fluid condition. If the ATF is black o
r
smells burnt, replace it.



RUW37ASH002501

ON-VEHICLE SERVICE (AW30 –40LE) 7A3-35

Shift Solenoid and Lock-Up Solenoid
Removal
Preparation:

Disconnect negative ( –) battery cable.
 Drain the fluid.
Refer to ATF REPLACEMENT in this section.
1. Remove oil lever gage and oil filler tube.
2. Support transfer case (4
4) or rear cover (42)
with a transmission jack.
3. Remove engine rear mounting nuts.


F07RW008
4. Remove fule pipe heat protector on tansmission
corssmenber.
5. Remove fuel pipe from the crossmenber.
6. Remove transmission crossmenber.
7. Remove the nineteen bolts.
8. Remove oil pan, using seal cutter J –37228.



RUW37ASH002901

NOTE: Do not turn over the transmission as this will
contaminate the valve body with foreign materials in the
bottom of the oil pan.
Remove oil pan by lifting the transmission case.
Oil pan seal cutter: J –37228
Examine particles in oil pan
Remove the magnet and use it to collect any steel
chips.
Look carefully at the chips and particles in the oil
pan and on the magnet to anticipate what type o
f
wear you will find in the transmission:
Steel (magnetic) ..................bearing, gear and
clutch plate wear
Brass (non-magnetic) ..........bushing wear



240RY00008
9. Remove the oil strainer assembly.



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7A3-50 ON-VEHICLE SERVICE (AW30 –40LE)

Major Components
Disassembly, inspection and reassembly of each
component group is indicated in the following chapter.
Before reassembly, make sure, again, that all
component groups are assembled correctly.
If something wrong is found in a certain component
group during assembly, inspect and repair this group
immediately.
General Assembly Notes:
1. The automatic transmission is composed of highly
precision-finished parts, necessitating careful
inspection before assembly because even a small
nick could cause fluid leakage or affect
performance.


2. Before assembling new clutch discs and brake
bands, soak them in automatic transmission fluid fo
r
at least thirty minutes.
3.
Apply automatic transmission fluid on the sliding or
rotating surfaces of parts before assembly.
4. Use petroleum jelly to keep small parts in thei
r
palces.
5. Do not use adhesive cements on gaskets and similar parts.
6. When assembling the transmission, be sure to use new gaskets and O-rings.
7. Dry all parts with compressed air - never use shop rags.
8. Be sure to install the thrust bearings and races in the correct direction and position.



Bearing and Race

RUW36AM F000201

UNIT REPAIR (AW30–40LE) 7A4–37
Diaassembly, Inspection and
Reassembly of minor Components
NOTE: The instructions here are organized so that you
work on only one component group at a time.
This will help avoid confusion from similar-looking parts
of different subassemblies being on your workbench at
the same time.
The component groups are inspected and repaired from
the converter housing side.
As much as possible, complete the inspection, repair
and reassembly before proceeding to the nex t
component group. If a component group cannot be
reassembled because parts are being ordered, be sure
to keep all parts of that group in separate container
while proceeding with disassembly, inspection, repair
and reassembly of other component groups.
Recommended ATF type DEXRON III.
General Cleaning Notes:
1. All disassembled parts should be washed clean and
any fluid passages and holes should be blown
through with compressed air.
2. When using compressed air to dry parts, always aim
away from yourself to prevent accidentally spraying
automatic transmission fluid in your face.
3. The recommended automatic transmission fluid
should be used for cleaning.
Parts Arrangement:
1. After cleaning, the parts should be arranged in
proper order to allow performing inspection, repairs,
and reassembly with efficiency.
2. When disassembling a valve body, be sure to keep
each valve together with the corresponding spring.
3. New brakes and clutches that are to be used for
replacement must be soaked in transmission fluid
for at least thirty minutes before assembly.
General Assembly:
1. All oil seal rings, clutch discs, clutch plates, rotating
parts, and sliding surfaces should be coated with
transmission fluid prior to reassembly.
2. All gaskets and rubber O-ring should be replaced.
3. Make sure that the ends of a snap ring are not
aligned with one of the cutouts and are installed in
the groove correctly.
4. If a worn bushing is to be replaced, the
subassembly containing that bushing must be
replaced.
5. Check thrust bearings and races for wear or
damage. Replace if necessary.
6. Use petroleum jelly or vaseline to keep parts in
place.

7A1-8 CONSTRUCTION AND FUNCTION
STRUCTURE AND FUNCTION OF COMPONENT
TORQUE CONVERTER (WITH LOCK-UP FUNCTION)

The torque converter is a device for transmitting the engine torque to the transmission. It transmits power
by means of oil when the lock-up is disengaged and by means of a lock-up piston when it is engaged.

The torque converter is of the symmetrical, three-element, single-stage, two-phase type.

As shown in the drawing, the symmetrical three-elements refer to three elements (components) consisting
of impeller (1), turbine (2) and stator (3) that are arranged symmetrically (figure 5).

"Single-stage" means that there is only one turbine as an output element; "two-phase" means that the
pump impeller acts as a torque converter when the turbine speed is comparatively low, and as a fluid
coupling when the speed is high.


















1. Pump Impeller
2. Turbine Runner
3. Stator














1. Pump Impeller
2. Turbine Runner
3. Stator
4. Converter Cover
5. One-way Clutch
6. Lock-up Piston
7. Torsion Damper

Figure 5. Torque Converter
Figure 6. Construction of Torque Converter

Lock-up mechanism

"Lock-up" refers to a fixed state of the lock-up piston inside the torque converter and thus connects the
engine directly to the transmission.

The hydraulic pressure for the lock-up control is supplied from two circuits.

When the lock-up is disengaged (Figure 7)

When the lock-up is disengaged, the torque converter operating pressure is supplied from the oil passage
(A) to between the cover and the lock-up piston, and separates the lock-up piston clutch facing and
converter cover.

As a result, the engine drive power is transmitted from the converter cover to the pump impeller, the ATF
and to the turbine. The torque converter function as a fluid connector in this condition.

The torque converter operating pressure is supplied from the oil passage (A), passes through the oil
passage (B).

When the lock-up is engaged (Figure 8)

When the lock-up is engaged, the torque converter operating pressure is supplied from oil passage (B) to
the oil pump impeller, turbine, then to the stator side. The oil between the lock-up piston and converter
cover is drained.

Since the force acting on the right side of the lock-up piston is greater than force on the left side, it
connects the lock-up piston clutch facing with the converter cover, thereby increasing the transmission
efficiency.