lock ISUZU TF SERIES 2004 Workshop Manual
[x] Cancel search | Manufacturer: ISUZU, Model Year: 2004, Model line: TF SERIES, Model: ISUZU TF SERIES 2004Pages: 4264, PDF Size: 72.63 MB
Page 3948 of 4264
7A1-2 CONSTRUCTION AND FUNCTION
PAGE
LOCK-UP CONTROL ..............................................................................................................7A1- 30
DIRECT ELECTRIC SHIFT CONTROL (DESC) ................................................................7A1- 31
LEARNING CONTROL ............................................................................................... 7A1- 33
MAJOR INPUT/OUTPUT COMPONENT AND THEIR FUNCTIONS .......................... 7A1- 34
CONTROL CIRCUIT BLOCK DIAGRAM .................................................................... 7A1- 35
GEAR TRAIN (TRANSMISSION MECHANISM) OPERATION AND
HYDRAULIC CIRCUIT ................................................................................................. 7A1- 36
CONSTRUCTION AND OPERATION ......................................................................... 7A1- 36
COMPONENT NAME AND FUNCTION ...................................................................... 7A1- 36
COMPONENT AND THEIR OPERATING CONDITION ............................................. 7A1- 37
Page 3949 of 4264
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
Page 3950 of 4264
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
Page 3952 of 4264
7A1-6 CONSTRUCTION AND FUNCTION
ELECTRONIC CONTROL COMPONENTS LOCATION
4WD Only 4WD Only
Instrument panel (Meter)
Speed meter (2WD Only)
Shift position indicator lamp
POWER DRIVE, 3rd START
indicator lamp
A/T OIL TEMP indicator lamp
CHECK TRANS indicator lam
p
Brake pedal
Brake Switch
Select lever
Power Drive
, 3rd Start select switch
Transmission Control Module (TCM)
Electrical source
Ignition
Battery voltage
Speed sensor
Turbine sensor
Inhibitor switch
ATF thermo sensor
High clutch oil pressure switch
2-4 brake oil pressure switch
Low & Reverse brake oil pressure
switch
Line pressure solenoid
Low clutch solenoid
High clutch solenoid
2-4 brake solenoid
Low & Reverse brake solenoid
Lock-up solenoid
Transmission
Transfer Control Module
Transfer
4L mode switch
Engine
Engine speed sensor
Throttle Position Sensor
Engine Control Module (ECM)
Data link connector
Page 3954 of 4264
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.
Page 3955 of 4264
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
Page 3956 of 4264
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
Page 3959 of 4264
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
Page 3961 of 4264
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 are turned ON or OFF at 50Hz. The ratio of the ON and
OFF time can be freely controlled in the range 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 the high clutch pressure,
the 2-4 brake solenoid the 2-4 brake pressure and the low & reverse brake solenoid 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 ON and
OFF time can be freely controlled in the range 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
Page 3962 of 4264
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