2004 ISUZU TF SERIES torque

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.

7A2-94 DIAGNOSIS (JR405E)
No. A2: Vehicle Does Not Run in R Range

Description:

Vehicle does not run in R range only.

It runs correctly in D, 3, 2, and L ranges.

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 (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 R but the hydraulic system is not in the 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 R 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.

DIAGNOSIS (JR405E) 7A2-95
No. A3: Vehicle Does Not Run in D, 3, 2 and L Range

Description:

Vehicle does not run in D, 3, 2 and L range only.

It runs correctly in R ranges.

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 and low one-way clutch).
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 and L but the hydraulic system is not in the D, 3, 2
and L 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 D, 3, 2 and L 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.

DIAGNOSIS (JR405E) 7A2-97
No. B2: Poor Acceleration at Starting

Description:

Starting acceleration is poor.

Diagnosis Hints:

In addition to the low engine output, faulty gear shifting of AT or fixing at the 3rd position may be possible.
Therefore, in case of such a trouble that "maximum speed is low, and acceleration is poor", it should be cleared
up whether the trouble is originated from the engine system of AT system by a running test, inspection of stall
revolution, etc.

Possible Cause:

Clogged air cleaner, out of injection timing, dropped compression pressure, etc.

Fixing at 3rd position (fail-safe activated).
Since the gear is fixed at the 3rd position because of the fail-safe function, a trouble that "Maximum
speed is low, and acceleration is poor" is resulted. In this case, the DTC is memorized.
When TCM stops operation because of faulty TCM ground, the gear is fixed at the 3rd position because
of a mechanical reason. In this case, no DTC is memorized.

Disordered inhibitor switch.

Incorrect properties of throttle opening signal (serial communication) of throttle position sensor.
Throttle opening signal (serial communication) of the throttle position sensor does not change in
proportion to the throttle opening. In this case, fixing at the high or low gear results in such a trouble
that "Maximum Speed is Low and Acceleration is Poor".

Slip of clutch (low clutch, high clutch).

If slip of clutch is caused, a DTC (gear ratio error) is stored.

Dropped line pressure.

Trouble in the torque converter system (faulty operation).

Step Action Yes No
1 Test Drive.
Is the gear smoothly shifted in the order of 1st to 2nd, 2nd to 3rd,
3rd to 4th gear and lock up?

Clogged air cleaner,
out of injection
timing, dropped
compression
pressure, etc.

Go to Step 2
2 Gear ratio trouble diagnosis.
Travel in the following sequence for about 7 seconds or more in
each range: Start in the L range (1st) to 2 range (2nd) to 3 range
(3rd) to D range (4th) (to detect the gear ratio trouble exactly, this
process should be carried out)
Go to Step 3 Go to Step 3
3 Are any DTCs stored?
Go to DTC Chart Go to Step 4

DIAGNOSIS (JR405E) 7A2-127
No. F1: Low Maximum Speed or Poor Acceleration

Description:

Starting acceleration is poor.

Acceleration is slow though the accelerator pedal is stepped on during the running.

Diagnosis Hints:

In addition to the low engine output, faulty gear shifting of AT or fixing at the 3rd position may be possible.
Therefore, in case of such a trouble that "maximum speed is low, and acceleration is poor", it should be cleared
up whether the trouble is originated from the engine system of AT system by a running test, inspection of stall
revolution, etc.

Possible Cause:

Clogged air cleaner, out of injection timing, dropped compression pressure, etc.

Fixing at 3rd position (fail-safe activated).
Since the gear is fixed at the 3rd position because of the fail-safe function, a trouble that "Maximum
speed is low, and acceleration is poor" is resulted. In this case, the DTC is memorized.
When TCM stops operation because of faulty TCM ground, the gear is fixed at the 3rd position because
of a mechanical reason. In this case, no DTC is memorized.

Disordered inhibitor switch .

Incorrect properties of throttle opening signal (serial communication) of throttle position sensor.
Throttle opening signal (serial communication) of the throttle position sensor does not change in
proportion to the throttle opening. In this case, fixing at the high or low gear results in such a trouble
that "Maximum Speed is Low and Acceleration is Poor".

Slip of clutch (low clutch, high clutch).

If slip of clutch is caused, a DTC (gear ratio error) is stored.

Dropped line pressure.

Trouble in the torque converter system (faulty operation).

Step Action Yes No
1 Test Drive.
Is the gear smoothly shifted in the order of 1st to 2nd, 2nd to 3rd,
3rd to 4th gear and lock up?
Clogged air
cleaner, out of
injection timing,
dropped
compression
pressure, etc. Go to Step 2
2 Gear ratio trouble diagnosis.
Travel in the following sequence for about 7 seconds or more in
each range: Start in the L range (1st) to 2 range (2nd) to 3 range
(3rd) to D range (4th) (to detect the gear ratio trouble exactly, this
process should be carried out)
Go to Step 3 Go to Step 3
3 Are any DTCs stored?
Go to DTC Chart Go to Step 4