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TRANSFER CASE
Position
Speed
Operation
Ratio
N
- Neutral position
-
(Available only in manual shift type transfer case). The out
put shaft is disconnected from the input shaft and no power
is transmitted to the wheels
2H
- Two high position
1: 1
Only the two rear wheels are driven and the transfer case
operates at 1: 1 speed ratio
4H
- Four high position
1: 1
All four wheels are driven at 1: 1 speed ratio
4L
- Four low position
2.48: 1
All four wheels are driven and the transfer case operates at
2.48: 1 speed reduction ratio
A planetary gear set is used to provide gear
reduction. Power is transferred to the front wheel
drive through a Morse Hi-Vo chain drive. Unit
operates in an oil bath. An oil pump is used to provide
positive lubrication to the planetary gear set and
other upper shaft components.
The different modes are obtained by rotating selector
switch for selection. This in turn gives signal to
Electronic Control Unit (ECU). ECU intelligently
controls operations. It senses the conditions and
shifts transfer case into the mode selected.
The control over the operations is obtained using
‘Electronic Control Unit (ECU)’. It consists of
1.
The control unit housed below the driver’s
seat or under dashboard
2.
Rotary switch provided for selection of
different modes
l
2H
l
4H
l
4L
3.
The indicator lights on the dashboard to
indicate the status (4H-4L)
TRANSFER CASEWORKING :
Divgi-Warner's 45-54 Transfer case is a two speed,
part time electric transfer case. The transfer case
operates in a system. The system consists of
1.
Transfer case with motor, speed sensor, and
electric clutch.
2.
Electronic control unit (ECU)
3.
Mode selector switch
4.
Indicator lights 4H and 4L
5.
Harness to connect the above parts and power
input.
The power is received by input shaft, which is
coupled with output shaft of transmission gearbox
by matching splines. There are two outputs, one for
rear wheels and one for front wheels.