torque ISUZU TF SERIES 2004 Workshop Manual

7A4–132 UNIT REPAIR (AW30–40LE)
Special Tools
ILLUSTRATIONTOOL NO.
TOOL NAME
J–37227
Holding fixture
J–3289–20
Holding fixture base
J–37228
Oil pan seal cutter
J–23327–1
Spring compressor
J–9617
Oil seal installer; oil
pump
J–37233
Spring compressor; OD
brake piston
J–29770–A
Oil pressure gauge
J–25048
Spring compressor
J–37236
Reaction sleeve puller;
first and reverse brake
J–37237
Piston puller; first and
reverse brake
J–37232–2
Oil seal installer;
manual valve shaft seal
installer & remover
J–35467
Onennway clutch
testing tool; torque
converter ILLUSTRATIONTOOL NO.
TOOL NAME

CONSTRUCTION AND FUNCTION 7A1-1

SECTION 7A1
CONSTRUCTION AND FUNCTION
TABLE OF CONTENTS
PAGE
DESCRIPTION ..............................................................................................................................7A1- 3
CONSTRUCTION ....................................................................................................................7A1- 3
MAIN DATA AND SPECIFICATION .....................................................................................7A1- 4
NUMBER PLATE LOCATION ...............................................................................................7A1- 5
ELECTRONIC CONTROL COMPONENTS LOCATION ..................................................7A1- 6
TRANSMISSION CONTROL UNIT (TCM) PERIPHERAL CIRCUIT ..............................7A1- 7
STRUCTURE AND FUNCTION OF COMPONENT ...........................................................7A1- 8
TORQUE CONVERTER (WITH LOCK-UP FUNCTION) ..................................................7A1- 8
OIL PUMP .................................................................................................................................7A1- 9
INPUT SHAFT ..........................................................................................................................7A1- 10
OUTPUT SHAFT ......................................................................................................................7A1- 10
GEAR SHIFTING MECHANISM ............................................................................................7A1- 10
CONTROL VALVE ...................................................................................................................7A1- 14
OIL PASSAGE .........................................................................................................................7A1- 19
PARKING FUNCTION .............................................................................................................7A1- 20
INHIBITOR SWITCH ...............................................................................................................7A1- 21
TURBINE SENSOR .................................................................................................................7A1- 22
SPEED SENSOR .....................................................................................................................7A1- 22
THROTTLE POSITION SENSOR (TPS) .............................................................................7A1- 23
ENGINE SPEED SENSOR (=TDC SENSOR) ....................................................................7A1- 23
BRAKE SWITCH ......................................................................................................................7A1- 24
MODE SELECT SWITCH .......................................................................................................7A1- 24
TRANSMISSION CONTROL MODULE (TCM) ..................................................................7A1- 25
CONTROL MECHANISM ............................................................................................................7A1- 26
CONTENT OF FUNCTION AND CONTROL ......................................................................7A1- 26
CONTROL ITEM, INPUT AND OUTPUT .................................................................... 7A1- 29
LINE PRESSURE CONTROL ..................................................................................... 7A1- 30

CONSTRUCTION AND FUNCTION 7A1-3

DESCRIPTION
CONSTRUCTION



































1 Converter Housing 6 Low Clutch 11 Oil Pump
2 Torque Converter 7 Low & Reverse Brake 12 Control Valve
3 High Clutch 8 Output Shaft 13 Low One-way Clutch
4 Reverse Clutch 9 Extension Housing 14 Parking Gear
5 2-4 Brake 10 Input Shaft

Figure 1. Construction of Automatic Transmission

The JR405E automatic transmission is electrically controlled by a microcomputer transmission control module
(TCM). There are four forward speeds and one reverse speed.
This JR405E automatic transmission employs a clutch pressure direct control system (Direct Electronic Shift
Control: DESC) using a duty cycle type solenoid, which ensures high shift quality.
This transmission also controls learning and constantly checks the time of each clutch and brake required for
the speed change to match this time with the target value for the optimum speed change.

The TCM will automatically select the most appropriate shift points and lock-up points depending on the
throttle opening angle, the vehicle speed and the vehicle load.
If any trouble arises in the vehicle sensor, throttle sensor, solenoid, etc., the fail-safe control function is
activated to keep the running performance.
Problems with the sensors, the solenoids can be quickly detected with the self diagnosis procedure described
in this manual.

The JR405E automatic transmission consists of the torque converter, the oil pump, the input shaft, the out put
shaft, the planetary gears and the control valve.
The gear train consists of two planetary gear sets and three multiple plate clutches in combination with two
multiple plate brakes and a one-way clutch.
2WD
4WD

7A1-4 CONSTRUCTION AND FUNCTION
MAIN DATA AND SPECIFICATION
Model JR405E
Torque Converter Type Three Elements, One Stage & Two Phase Type
With Lock-up Function
Torque Converter Stall Torque Ratio 1.8
Name ATF DEXRON

Quantity 9.2L-9.6L AT F
Cooling System Water Cooled Type (Radiator)
1st 2.786
2nd 1.546
3rd 1.000
4th (Over Drive) 0.694
Gear Ratio
Reverse 2.273
Low Clutch L/C 7
High Clutch H/C 5
Reverse Clutch R/C 2Number of Disc Clutch
Low One-way Clutch L/O.C 1 Set
Low & Reverse
Brake L&R/B 6
Brake
2-4 Brake 2-4/B 5Number of Disc
Sun Gear 33
Pinion
Gear 21Front Planetary
Ring Gear 75
Sun Gear 42
Pinion
Gear 17
Planetary Gear Unit
Rear Planetary
Ring Gear 75Number of Teeth

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.

CONSTRUCTION AND FUNCTION 7A1-9


Figure 7. Lock-up Control (Disengaged) Figure 8. Lock-up Control (Engaged)
OIL PUMP

The oil pump generating oil pressure is a small-size trochoid gear type oil pump. It feeds oil to the torque
converter, lubricates the power train mechanism, and feeds the oil pressure to the oil pressure control unit
under pressure.

The oil pump is located behind the torque converter. Sine the inner rotor in the oil pump is fitted with the
drive sleeve of the torque converter, it works by the power from the engine.

Figure 9. Construction of Oil Pump Figure 10. Location of Oil Pump

When the inner rotor in the oil pump rotates, ATF is sucked in from the oil pan, passed between the inner
rotor, outer rotor and crescent and discharged. This pressure discharged is sent to the pressure
regulator valve in the control valve and adjusted as required for operating the A/T. The flow rate under
pressure increases or decreases in proportion of the number of rotations.


Figure 11. Operation of Oil Pump

7A1-10 CONSTRUCTION AND FUNCTION
INPUT SHAFT

The input shaft has some oil holes, through which lubricating ATF is supplied to the torque converter,
bearings, etc.

The input shaft is fitted the turbine runner in the torque converter, reverse & high clutch drum and rear sun
gear by means of the spline. Therefore, the engine driving force received by the torque converter is
transmitted to the reverse & high clutch drum and rear sun gear.

OUTPUT SHAFT

The output shaft has some oil holes, through which the lubricating ATF is supplied to the bearings,
planetary gear unit, etc.

The output shaft transmits the engine driving force from the planetary gear to the propeller shaft.

The front internal gear is fitted with the rear carrier assembly by spline. The parking gear is also fitted by
spline. By fixing this gear mechanically, the output shaft is fixed as required when parking the vehicle.

GEAR SHIFTING MECHANISM

The JR405E consists of two sets of planetary gears, three multiple plate clutches, two multiple plate
brakes and a one-way clutch. They are activated in different combinations in any of four forward and one
reverse gear positions.

Principle of gear shifting (Figure 12)

Planetary gears have the advantage of a compact configuration because of the way they are constructed
with a single central shaft.

Also, unlike the manual transmission gears that require changing of gear mesh, the gear ratio of the
planetary gears can be changed more easily by locking, releasing or rotating only some of their parts.

A planetary gear is made up of a sun gear (1) at its center and pinion gears (2) each of which rotates
about its own center and also along the sun gear, as shown. They are all called in the internal gear (3).

Also, since the pinion gears are further supported by the planetary carrier (4), they rotate as a unit in the
same direction and at the same rate.

As shown above, each planetary gears are constructed of three elements; a sun gear, pinion gears, and
internal gear and a planetary carrier. Gear shifting is achieved by conditioning two of the three elements
namely the sun gear, internal gear and the planetary carrier.

The planetary gears are locked by the clutch, brake and one-way clutch according to the gear shifting.
















1. Sun Gear
2. Pinion Gear
3. Internal Gear
4. Planetary Carrier

Figure 12. Planetary Gear

CONSTRUCTION AND FUNCTION 7A1-41
1st Gear in D, 3, 2 Range
The driving force from the input shaft is transmitted to the rear sun gear and reverse & high clutch drum.
Since the low clutch is engaged, the movement of the rear internal gear is restricted and, since the low one-
way clutch acts at the same time, counterclockwise rotations of the rear internal gear are locked. As a result,
the driving force transmitted to the rear sun gear rotates the rear planetary carrier clockwise, is decreased in
speed and transmitted to the output shaft.
When decelerating, since the rotating speed of the rear planetary carrier (rear pinion gear) is higher than that
of the rear sun gear and therefore, the rear internal gear attempts to rotate clockwise. At this time, the low
one-way clutch does not act but races and therefore the rear internal gear rotates clockwise. That is, the
reverse torque from the driving shaft is not transmitted to the engine side and therefore, the engine brake
does not act.

7A1-42 CONSTRUCTION AND FUNCTION
1st Gear in L Range
The basic mechanism is the same as in the D, 3, and 2 Range. To apply the engine brake, the low & reverse
brake is engaged to restrict the movement of the low one-way clutch.
When decelerating, since the rear internal gear is fixed, reverse torque from the drive shaft is transmitted to
the engine side so that the engine brake is applied.

DIAGNOSIS (JR405E) 7A2-93
No. A1: Vehicle Does Not Run in D, 3, 2, L and R Range

Description:

Vehicle does not run though the accelerator pedal is stepped on.

Diagnosis Hints:

Some trouble in the AT main unit is supposed (since the vehicle can run even if the TCM is defective). However,
since the trouble of the main unit may be originated from the sensor system or output system, these systems
should be also checked to prevent reproduce of the trouble.

Possible Cause:

Slip of clutch (low clutch, low one-way clutch, reverse clutch, low & reverse brake).
If slip of clutch is caused, a DTC (gear ratio error) is stored.

Shortage or faulty quality of ATF.

Dropped line pressure.

Trouble in control valve body (faulty operation, sticking, clogged oil passage).

Disordered select cable (select indicator light indicates D, 3, 2, L or R but the hydraulic system is not in the D, 3,
2, L, or R range).

Faulty torque generated.

Trouble in the torque converter (faulty operation, sticking), insufficient engine output.

Malfunction of parking mechanism.

Step Action Yes No
1 Dislocation or disordered of select lever.
Does the vehicle move when the brake is released in a
position other than the P range and the vehicle is pushed?

Go to Step 2

Adjust the select cable.
2 Are any DTCs stored?
Go to DTC Chart Go to Step 3
3 Are the quantity, contamination and smell normal?
If the ATF level is low,
replenish up to the
specified level.

Go to Step 4
If ATF is extremely
black and
contaminated and
smells burnt, slip of the
clutch is supposed.
Overhaul the AT unit.
4 Is the stall revolution correct in all range? Refer the STALL
TEST section in this manual.
Go to Step 5
Repair the defect or
replace.
5 Is the line pressure correct? Refer the LINE PRESSURE
TEST section in this manual. Trouble in the AT
assembly or control
valve.
Repair the defect or
replace.