oil ISUZU TF SERIES 2004 Workshop Manual

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 7A1-11


The JR405E consists of two sets of planetary gears, which are called front planetary gear and rear
planetary gear.

The sun gear of front planetary gear is fixed to the drive plates of 2-4 brake and reverse clutch.

The planetary carrier of front planetary gear is fixed to the drum of low clutch, the drive plates of low &
reverse brake and the hub of high clutch.

The internal gear of front planetary gear and the planetary carrier of rear planetary gear are connected as
one, and they are fixed to output shaft.

The sun gear of rear planetary gear is fixed to input shaft.

The internal gear of rear planetary gear is fixed to the hub of low clutch.

Clutch and Brake

Basic structure of the clutch and brake is shown in the figures below.

In the figure A, the clutch plates (drive plate and driven plate) are in the fluid so that they slip against each
other transmitting no power.

Figure B shows the condition where the oil pressure is acting on the piston. The clutch plates are fitted
to each other under pressure transmitting the rotations of the clutch drum to the clutch hub.

When the oil pressure is removed from the piston, the clutch returns to the condition in the figure A by the
return spring.


Figure 13. Basic Construction of Clutch and Brake

Low Clutch, High Clutch and Reverse Clutch (Multi-Plate Clutch)

The multi-plate clutch is composed of drive plates and driven plates. By applying the oil pressure onto
the end surface of the plates, the clutch is engaged or disengaged. The oil pressure is adjusted with the
control valve according to the signal from the TCM.

All clutches use dish plates to prevent uncontrolled operation of the clutches when engaged, causing a
shock.

For the reverse clutch, a piston check ball is used to release the oil pressure for the purpose of preventing
the clutch drag due to oil pressure generated by residual ATF because of the centrifugal force while the
clutch is racing (under no oil pressure).

For the low clutch and high clutch, a centrifugal balance chamber always full of ATF is provided to offset
the excessive oil pressure, for the purpose of preventing the clutch drag due to oil pressure generated by
residual ATF because of the centrifugal force while the clutch is racing (under no oil pressure).

The solenoid in the control valve is driven based on the speed change signal from TCM and moves the
shift valve, thereby engaging the drive plate and driven plate through the piston of each clutch.

Resultantly, elements of the planetary gear unit are combined.

When the oil pressure is removed, the piston returns to the original position by the force of the return
spring.

CONSTRUCTION AND FUNCTION 7A1-13

2-4 Brake and Low & Reverse Brake (Multi-Plate Brake)

The multi-plate brake is composed of drive plates and driven plates. By applying the oil pressure onto
the end surface of the plates, the clutch is engaged or disengaged. The oil pressure is adjusted with the
control valve according to the signal from the TCM.

All brakes use dish plates to prevent uncontrolled operation of the clutches when engaged, causing a
shock.

The solenoid in the control valve is driven based on the speed change signal from TCM and moves the
shift valve, thereby engaging the drive plate and driven plate through the piston of each clutch.

Resultantly, rotation of each element of the planetary gear unit is fixed.

When the oil pressure is removed, the piston returns to the original position by the force of the return
spring.




Figure 19. Construction of 2-4 Brake
Figure 20. Construction of Low & Reverse Brake

Low One-way Clutch

The low one-way clutch employs the sprag which locks the counterclockwise rotation of the front planetary
carrier and rear internal gear.

The one-way clutch outer race is fitted with the low clutch drum and the inner race with the transmission
case.

The outer race rotates freely clockwise but, when it attempts to rotate counterclockwise, the sprag
functions to lock the outer race.

When the vehicle is traveling in 1st gear in the D, 3 or 2range, the low one-way clutch locks the rear
internal gear via the low clutch. It is left free in the 2nd, 3rd or 4th gear position.


Figure 21. Construction of Low One-way Clutch

7A1-14 CONSTRUCTION AND FUNCTION
CONTROL VALVE

Employing the direct electronic control (Direct Electronic Shift Control: DESC) for the clutch pressure has
simplified the oil pressure circuit, reduced the number of functional components and made the control
valve compact.

The control valve body is divided into the upper body and lower body. All solenoids, oil pressure switch
and ATF thermo sensor are installed to the lower body.

Three-way valve type solenoids providing high responsibility are employed. Some of the solenoids are
switched between ON and OFF and others repeat ON and OFF at 50Hz (duty cycle system).
Functionally, some supply output pressure when power is not supplied and others drain the output
pressure.

When the solenoid is driven based on the signal from the TCM, the oil pressure is changed. The valve is
operated by the difference of the oil pressure.


Figure 22. Construction of Valve Body

7A1-16 CONSTRUCTION AND FUNCTION
Control Valve Fail-safe Function

To prevent interlocking due to engagement of more than three clutches and brakes at the same time, the
2-4 brake fail-safe valve A and B, and the low & reverse brake fail-safe valve A and B are provided.

When oil pressure is generated in the high clutch and the low clutch, the 2-4 brake solenoid is turned ON
to drain the oil pressure applied to the 2-4 brake.

When oil pressure is generated in the high clutch or 2-4 brake, the low & reverse brake solenoid is turned
ON to drain the oil pressure applied to the low & reverse brake.



Oil Pressure Switch

The oil pressure switch detects the oil pressure supply condition to the clutch and brake and sends the
detection result to the TCM.

The oil pressure switch is turned ON when the oil pressure reaches the switch working pressure and
turned OFF when the pressure decreases below the specified value.

The high clutch oil pressure switch detects the high clutch oil pressure, 2-4 brake oil pressure switch the
2-4 brake oil pressure, and the low & reverse brake oil pressure switch the low & reverse brake oil
pressure respectively.




Figure 27. Oil Pressure Switch Figure 28. Location of Oil Pressure Switch

CONSTRUCTION AND FUNCTION 7A1-17

ATF Thermo Sensor

The ATF thermo sensor detects the ATF temperature in the oil pan and sends signal to the TCM.

The ATF thermo sensor is of the thermister type that the resistance value changes according to the ATF
oil temperature.

The lower is the ATF temperature, the larger is the resistance, and vice versa.

When the ATF temperature exceeds 145C, the TCM lights up the ATF temperature warning lamp in the
meter. When the ATF temperature decreases below 128C, the ATF temperature warning lamp goes out.

The ATF thermo sensor is installed to the lower control valve body and integrated with the harness
assembly.













10.0 100.0 1,000.0 10,000.0 100,000.0
-30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160
A TF Temperature (°C)
Resistance (

)

Figure 29. Characteristic of Thermo Sensor


Figure 30. Location of Thermo Sensor
ATF Temperature
(deg. C) Resistance (Ohm)
(Approximately) ATF Temperature
(deg. C) Resistance (Ohm)
(Approximately)
-30 29,614 100 190
-20 16,705 110 149
-10 9,842 120 118
0 6,028 128 98
20 2,500 130 94
40 1,160 135 84
50 819 140 76
60 591 145 68
80 324 150 62

7A1-18 CONSTRUCTION AND FUNCTION
Terminal Assembly
Pin No. Connected to Connected TCMPin No.
6 Line Pressure Solenoid B23
12 Low & Reverse Brake Oil Pressure Switch B12
5 Low & Reverse Brake Duty Solenoid B6
11 Ground Return B22
4 Lock-up Duty Solenoid B17
10 High Clutch Duty Solenoid B8
3 Low Clutch Duty Solenoid B9
9 2-4 Brake Duty Solenoid B7
2 Oil Thermo Sensor B4
8 Oil Thermo Sensor Ground B14
1 High Clutch Oil Pressure Switch B20
7 2-4 Brake Oil Pressure Switch B1


123456
891011127

Terminal Assembly Inhibitor Switch
Figure 31. Pin Assignment Figure 32. Location of Terminal Assembly

CONSTRUCTION AND FUNCTION 7A1-19

OIL PASSAGE




Figure 33. Oil Passage of Transmission Case

7A1-20 CONSTRUCTION AND FUNCTION


Figure 34. Oil Passage of Oil Pump

PARKING FUNCTION

By setting the select lever to the P range, the parking pawl is engaged with the parking gear and fixes the
output shaft.

By the movement of the select lever, the manual shaft on the side surface of the AT is moved. The
manual plate and parking rod in the AT are interlocked with the manual shaft. When the manual shaft
moves, the parking rod end pushes up the parking pawl.

The parking pawl is engaged with the parking gear when pushed up, and fixes the output shaft.

When the clutch is disengaged, it returns to the original position by the force of the return spring fixed to
the parking pawl.


Figure 35. Parking Function

CONSTRUCTION AND FUNCTION 7A1-25
TRANSMISSION CONTROL MODULE (TCM)

The TCM is fitted side of brake pedal by means of two stud bolts.

The TCM judges necessary line pressure, gear shifting point and lock-up operation based on electrical
signals from switches and sensors and sends appropriate signals to solenoids.















        




















 
 
 
 
 
 
 












      
  

Connect to White Connector Connect to Grey Connector


Figure 49. Pin Assignment

Pin No. Pin Assignment Pin No.Pin Assignment
B1 2-4 Brake Oil Pressure Switch A1 V BATT (Battery Back-up Power Supply)
B2 2 Range Switch A2 P Range Switch
B3 Turbine Sensor A3 Brake Switch
B4 ATF Thermo Sensor A4 3rd Start Indicator Lamp
B5 Ground A5 K-Line Signal (Tech 2 Serial Communication)
B6 Low & Reverse Brake Duty Solenoid A6 No Connection
B7 2-4 Brake Duty Solenoid A7 Engine Speed Sensor
B8 High Clutch Duty Solenoid A8 No Connection
B9 Low Clutch Duty Solenoid A9 No Connection
B10 N Range Switch A10 Vehicle Speed Sensor Out (2WD Only)
B11 D Range Switch A11 3rd START Select Switch
B12 Low & Reverse Brake Oil Pressure Switch A12 4L Mode Switch (4WD Only)
B13 Vehicle Speed Sensor A13 No Connection
B14 ATF Thermo Sensor Ground A14 No Connection
B15 Ground A15 No Connection
B16 No Connection A16 Throttle Position Sensor
B17 Lock-up Duty Solenoid A17 3 Range Switch
B18 Vign
Ignition Power Supply) A18 DIAG Switch (Test Switch)
B19 R Range Switch A19 A/T OIL TEMP Indicator Lamp
B20 High Clutch Oil Pressure Switch A20 CHECK TRANS Indicator Lamp
B21 L Range Switch A21 POWER DRIVE Indicator Lamp
B22 Ground (Shift Solenoid) A22 No Connection
B23 Line Pressure Solenoid A23 No Connection
B24 Vign (Ignition Power Supply) A24 POWER DRIVE Select Switch