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7A1-10 CONSTRUCTION AND FUNCTION
INPUT SHAFT
• The input shaft has some oil holes, through which lubricating ATF is supplied to the torque converter, the
bearings, etc.
• The input shaft is fitted to the turbine runner in the torque converter, the reverse & high clutch drum and
the 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, the
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 the 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 around the sun gear, as shown. They are all contained within 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 below, each planetary gear is constructed of three elements; a sun gear, pinion gears, an
internal gear and a planetary carrier. Gear shifting is achieved by conditioning two of the three elements,
namely the sun gear, the internal gear and 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
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Page 4250 of 6020

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 the front planetary gear is fixed to the drive plates of 2-4 brake and reverse clutch.
• The planetary carrier of the front planetary gear is fixed to the drum of the low clutch, the drive plates of
the low & reverse brake, and the hub of the high clutch.
• The internal gear of the front planetary gear, and the planetary carrier of the rear planetary gear, are
connected as one and fixed to the output shaft.
• The sun gear of the rear planetary gear is fixed to the input shaft.
• The internal gear of the rear planetary gear is fixed to the hub of the 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 released 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 figure A via 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. 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. This prevents clutch drag
caused by oil pressure generated by residual ATF due to the centrifugal force while the clutch is racing
(under no oil pressure).
• For the low clutch and high clutch, a centrifugal balance chamber full of ATF is provided to offset the
excessive oil pressure. This prevents clutch drag caused by oil pressure generated by residual ATF due
to the centrifugal force while the clutch is racing (under no oil pressure).
• The solenoid in the control valve is driven based on the shift signal from TCM, it moves the shift valve,
thereby engaging the drive plate and driven plate through the piston of each clutch.
• As a result, elements of the planetary gear unit are combined.
• When the oil pressure is removed, the piston returns to the original position via the force of the return
spring.
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Page 4251 of 6020
7A1-12 CONSTRUCTION AND FUNCTION
Figure 14. Basic Construction of Low Clutch and High Clutch Figure 15. Basic Construction of Reverse Clutch
Figure 16. Construction of Low Clutch Figure 17. Construction of High Clutch
Figure 18. Construction of Reverse Clutch
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Page 4252 of 6020

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. 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 shift signal from TCM, it moves the shift valve,
thereby engaging the drive plate and driven plate through the piston of each clutch.
• As a result, rotation of each element of the planetary gear unit is fixed.
• When the oil pressure is removed, the piston returns to the original position via 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 the rear internal gear.
• The one-way clutch outer race is fitted with the low clutch drum, and the inner race is fitted with the
transmission case.
• The outer race rotates freely clockwise, but, when it attempts to rotate counterclockwise, the sprag locks
the outer race.
• When the vehicle is traveling in 1st gear in the D, 3 or 2 position, 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.
Figure 21. Construction of Low One-way Clutch
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Page 4253 of 6020
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 the lower body. All solenoids, the oil pressure
switch and the 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.
Figure 22. Construction of Valve Body
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Page 4254 of 6020

CONSTRUCTION AND FUNCTION 7A1-15
Line Pressure Solenoid • The line pressure solenoid is turned ON or OFF according to the signal from the TCM. It switches the
line pressure between high and low pressure.
• While no power is supplied, the solenoid supplies high pressure.
Shift Solenoid • The shift solenoid is of the duty cycle type, which is turned ON or OFF at 50Hz. The ratio of the ON and
OFF time can be freely controlled in the position of 0 - 100%.
• While no power is supplied, the solenoid supplies output pressure.
• The low clutch solenoid adjusts the low clutch pressure, the high clutch solenoid adjusts the high clutch
pressure, the 2-4 brake solenoid adjusts the 2-4 brake pressure, and the low & reverse brake solenoid
adjusts the low & reverse brake pressure respectively.
Lock-up Solenoid • The lock-up solenoid is of the duty cycle type which is turned ON or OFF at 50Hz. The ratio of the ON
and OFF time can be freely controlled in the position of 0 - 100%.
• While no power is supplied, the solenoid drains the output pressure.
Figure 23. Shift Solenoid Figure 24. Lock-up Solenoid
Figure 25. Location of Solenoid
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Page 4255 of 6020

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 condition of the oil pressure supply to the clutch and brake, and then
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, the 2-4 brake oil pressure switch
detects the 2-4 brake oil pressure, and the low & reverse brake oil pressure switch detects he low &
reverse brake oil pressure respectively.
Figure 27. Oil Pressure Switch Figure 28. Location of Oil Pressure Switch
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CONSTRUCTION AND FUNCTION 7A1-17
ATF Thermo Sensor • The ATF thermo sensor detects the ATF temperature in the oil pan and sends a signal to the TCM.
• The ATF thermo sensor is of the thermister type and the resistance value changes according to the ATF
oil temperature.
• When the ATF temperature is cold, the sensor resistance is high. When the ATF temperature increases,
the sensor resistance decreases.
• When the ATF temperature increases to 135 °C (275 °F), the TCM lights up the ATF temperature warning
lamp in the meter. When the ATF temperature decreases below 125 °C (257 °F), the ATF temperature
warning lamp switches off.
• 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 Temp er a t ur e ( °C)
Resistance (Ω
)
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 100190
-20 16,705 110149
-10 9,842 120118
0 6,028 128 98
20 2,500 130 94
40 1,160 135 84
50 819 140 76
60 591 14568
80 324 15062
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