2004 ISUZU TF SERIES Trans axle

7D1-20 TRANSFER CONTROL SYSTEM
4H




Neutral




4H
Item 4WD
lamp 4L lampNeutral
lamp Check
4WD
warning
light 4WD
switch Actuator
detection
(limit)
switches
LS1, LS2,
LS3. and
LS4
1 = on
2 = off Transfer
4WD
switch Transfer
neutral
switch SOF
actuator
switch
Or
Axle
dummyRemarks
4H On Off Off Off No
operation0,0,1,1 Closed Open Closed -----
Neutral
start of
operation On On Off Off Neutral
position
for 10
seconds 1,1,0,1 Closed Open Closed -----
Start of
operation Off Off Blinking
(2HZ) Off No
operation1,1,0,0 Closed Open Closed 4L to N
while
driving
During
operation
(N) Off Off Blinking
(2HZ) Off No
operation1,1,0,0 Closed Closed Closed 4L to N
with axle
driving
During
operation
(N) Off Off Blinking
(2HZ) Off No
operation0,1,0,0 Closed Closed Closed 4L to 4N
with axle
removed
During
operation
(Axle) Blinking
(2HZ) Off Off Off No
operation0,1,1,1
0,1,1,0
0,0,1,0
1,1,1,0 Open Open Closed Axle
driving
Axle
waiting
Blinking
(2HZ) Off Off Off No
operation1,0,1,0 Open Open Closed -----
Neutral Off Off On Off No
operation0,1,0,0 Closed Closed Open -----
4H start
of
operation Off Off Off Off 2H
position
for 10
seconds 0,1,0,0 Open Open Open Switch
operation
sensor
During
operation
(N) Off Blinking
(2HZ) Off Off No
operation1,1,0,0 Closed Closed Open 4L to 4H
through
neutral
During
operation
(N) Off Blinking
(2HZ) Off Off No
operation0,1,0,0 Closed Closed Open 4L to 4H
through
neutral
During
operation Off Blinking
(2HZ) Off Off No
operation0,1,0,1
0,0,0,1 Closed Closed Open 4L to 4H
while
driving
4H
waiting Blinking
(2HZ) Off) Off Off No
operation0,0,1,1 Closed Closed Open 4L to 4H
while
waiting
During
operation
(Axle) Blinking
(2HZ) Off Off Off No
operation0,0,1,1 Closed Open Open Axle
driving
Axle
waiting
Blinking
(2HZ) Off Off Off No
operation0,0,1,1 Closed Open Open -----
4H On Off Off Off No
operation0,0,1,1 Closed Open Closed -----

7D1-22 TRANSFER CONTROL SYSTEM
4L




Neutral




4L

Item 4WD
lamp 4L lampNeutral
lamp Check
4WD
warning
light 4WD
switch Actuator
detection
(limit)
switches
LS1, LS2,
LS3. and
LS4
1 = on
2 = off Transfer
4WD
switch Transfer
neutral
switch SOF
actuator
switch
Or
Axle
dummyRemarks
4L On On Off Off No
operation1,1,0,1 Closed Open Closed -----
Neutral
start of
operation On On Off Off Neutral
position
for 10
seconds 1,1,0,1 Closed Open Closed -----
Start of
operation Off Off Blinking
(2HZ) Off No
operation1,1,0,0 Closed Open Closed 4L to N
while
driving
During
operation
(N) Off Off Blinking
(2HZ) Off No
operation1,1,0,0 Closed Closed Closed 4L to N
with axle
driving
During
operation
(N) Off Off Blinking
(2HZ) Off No
operation0,1,0,0 Closed Closed Closed 4L to 4N
with axle
removed
During
operation
(Axle) Blinking
(2HZ) Off Off Off No
operation0,1,0,0 Closed Closed Closed Axle
driving
Axle
waiting
Blinking
(2HZ) Off Off Off No
operation0,1,0,0 Closed Closed Closed -----
Neutral Off Off On Off No
operation0,1,0,0 Closed Closed Open -----
4L start of
operation Off Off On Off 4L
position
for 10
seconds 0,1,0,0 Open Open Open Switch
operation
sensor
During
operation
(N) Off Blinking
(2HZ) Off Off No
operation1,1,0,0 Closed Closed Open 4H to 4L
through
neutral
During
operation
(N) Off Blinking
(2HZ) Off Off No
operation1,1,0,0 Closed Closed Open 4H to 4L
through
neutral
During
operation
(N) Off Blinking
(2HZ) Off Off No
operation1,1,0,0 Closed Closed Open 4H to 4L
through
neutral
4H
waiting On Blinking
(2HZ) Off Off No
operation1,1,0,1 Closed Closed Open 4L while
waiting
During
operation
(Axle) Blinking
(2HZ) Off Off Off No
operation1,1,0,1 Closed Open Open Axle
driving
Axle
waiting
Blinking
(2HZ) Off Off Off No
operation1,1,0,1 Closed Open Open -----
4H On On Off Off No
operation1,1,0,1 Closed Open Closed -----

Operational restrictions (vehicle speed, engine speed, and transmission position) are applicable to transfer
shifts in both directions (H
Neutral
L).

7D1-34 TRANSFER CONTROL SYSTEM

Diagnosis
Before determining a trouble (Non-trouble mode)
1. When shifting from 2H to 4H:
1-1-1 When the flashing frequency of the 4WD indicator is changed from 2Hz to 4Hz (Shft on the fly)
If the load is too large to shift the gears synchronously, the operation is repeated up to 3 times. If the shifting
is not effected after being repeated 3 times, the indicator frequency is changed from 2Hz to 4Hz and, at the
same time, the actuator condition is changed to 2H, indicator flashes at 4Hz for 10 seconds, and then goes
out.
Cause of excessive synchronous shifting load

Extremely low temperature (the oil viscosity of the front differential increases requiring a large load for
synchronization)
 High speed (since the difference of relative revolutions of gears to be shifted synchronously is too large,
required work load per unit time becomes larger).
Step 1-1-1:
Stop the vehicle or decrease the speed and operate as required again.

1-1-2 When the flashing frequency of the 4WD indicator is changed from 2Hz to 4Hz (Rigid and free wheel
Hub) / Block out of meshing spline.
Step 1-1-2:
Run the vehicle forward and backward several meters and operate as required again.

1-2 When the flashing of 4WD indicator at 2Hz continues more than 11.5 seconds (repetition of 3 times of
above No.1 is counted) (Shift on the fly)
If there is difference of revolutions and phases between the front wheel and axle, connecting the front wheel
and axle is difficult.
Until shifting in the transfer and connection of the front wheel and axle are completed

, the indicator flashes
at a frequency of 2Hz. In the above case, the indicator continues flashing at a frequency of 2Hz until the
connection of the front axle is completed. (If the shifting in the transfer is not completed, the flashing
frequency is changed to 4Hz (above No.1).)
By correcting the difference of relative revolutions and deviation of phases, the shifting can be completed.
Step 1-2:
While the vehicle is running, make sure of safety around the vehicle and accelerate or decelerate the
vehicle while going straight.
When the vehicle is at a stop, run the vehicle forward and backward several meters.

2.
When shifting from 4H to 2H
2-1 When 4WD indicator continues flashing at 2Hz
When shifting from 4H to 2H, the 4WD indicator continues flashing at 2Hz until separation in the transfer and
the separation of the front wheel axle are completed
. When torsional torque is accumulated in the drive
system, separation in the transfer and separation of the front axle
is difficult. In such a case, they can be
separated by removing the torsional torque of the drive system.
Step 2-1:
While the vehicle is running, make sure of safety around the vehicle and accelerate or decelerate the
vehicle while going straight.
When the vehicle is in stop, run the vehicle several meters forward and backward.


: Shift on the fly only.

TRANSFER CONTROL SYSTEM 7D1-43
Even after the correction step 1-2(*), the 4WD indicator still blinks at 2Hz when shifting
from 2H to 4H.
Step Action Yes No
1 Check the air pressure and wear
of all the tires. Is any trouble
noticed? After adjusting the air pressure
and repairing the tire worn away,
try the correction step 1-2(*). Go to step 2.
2 Check the 4WD detection switch
on the transfer case, neutral
detection switch and each
harness. Is a trouble noticed? 4WD detection switch is open or
the harness failed.
The neutral detection switch is
closed or the harness GND is
shorted.
Replace or repair and then trace
this chart from the beginning. Go to step 3.
3 Is there continuity in the harness
between the transfer controller
and front axle actuator? Isn’t a
body short or disconnection
noticed? Go to step 4. Body short or disconnection of
the harness between the transfer
controller and front axle actuator.
After repairing, trace this chart
from the beginning.
4 Is a trouble noticed in the axle
detection harness between the
axle actuator and transfer
controller? Disconnected harness.
After repairing trace this chart
from the beginning. Malfunction of axle actuator.
Refer to the paragraph of the
axle disconnect.
After repairing, trace this chart
from the beginning.
*Before determining a trouble (Non-trouble mode)
Note:
The vehicle of manual hub and rigid hub don’t have axle actuator.
When the above-mentioned procedure is followed, check the harness between the axle dummy output terminal and
the axle switch input terminal of transfer controller instead of axle actuator.

7D1-46 TRANSFER CONTROL SYSTEM
Even after the correction step 2-1(*), the 4WD indicator still blinks at 2Hz when shifting
from 4H to 2H.
Step Action Yes No
1 Check all the tires for air
pressure and wear. Is any
trouble noticed? After adjusting the air pressure
and repairing the tire worn away,
try the correction step 2-1(*). Go to step 2.
2 Check the 4WD detection switch
on the transfer case and neutral
detection switch and each
harness. Is a trouble noticed? 4WD detection switch is closed
or the GND short of harness.
The neutral detection switch is
closed or the harness GND is
shorted.
Replace or repair and then trace
this chart from the beginning. Go to step 3.
3 Is there continuity in the harness
between the transfer controller
and axle actuator?
Isn’t short or disconnection
noticed?
Isn’t the connection mistaken? Go to step 4. Body short, disconnection or
incorrect connection of the
harness between the transfer
controller and actuator.
After repairing, trace this chart
from the beginning.
4 Is a trouble noticed in the axle
detection harness between the
axle actuator and transfer
controller? GND short of harness Malfunction of axle actuator.
Refer to the paragraph of axle
disconnect.
After repairing, trace this chart
from the beginning.
*Before determining a trouble (Non-trouble mode)

Note:
The vehicle of manual hub and rigid hub don’t have axle actuator.
When the above-mentioned procedure is followed, check the harness between the axle dummy output terminal and
the axle switch input terminal of transfer controller instead of axle actuator.

7A3-40 ON-VEHICLE SERVICE (AW30 –40LE)

Rear Oil Seal (Adapter Housing, 4
 
4)

Removal

1. Remove the front and rear propeller shaft assembly
from the transfer case.
2. Remove the transfer case assembly from the transmission case.
Refer to Section 4 DRIVELINE/AXLE.
3. Using a screwdriver, remove the rear oil seal.
Installation
1. Apply ATF to a new rear oil seal lip.
2. Using oil seal installer, install the rear oil seal to the adapter housing.
Oil seal installer : J –36797



RUW37ASH002401
3. Install the transfer case assembly.
Refer to section 4 DRIVE/AXLE.
4. Install the front and rear propeller shaft assembly.
Torque (Propeller shaft flange bolt) : 63 N 


m (46
Ib ft)