Operation

TRANSFER BOX
Drive is transmitted to the transfer box from the gearbox output shaft, which is permanently engaged in the sun gear of the epicyclic gear set. In high range the sun gear transmits drive directly to the selector sleeve. In low range, when the selector spool has moved the selector sleeve, the sun gear transmits drive through the planet carrier.

The rotation of the selector sleeve is transferred to the intermediate shaft. A gear attached to the intermediate shaft carries the morse chain which transfers the drive to the differential unit.

The rear output shaft passes through the differential unit and rotates at the same speed. The viscous coupling passes drive from the rear output shaft to the front output shaft. When the silicon fluid in the viscous coupling becomes warm its resistance to shear increases passing more drive to the front drive shaft increasing traction.

ELECTRICAL OPERATION

WITH AUTOMATIC TRANSMISSION

Range change

NOTE: Range changes should be performed with the vehicle stationary and although range changes are possible at very low speeds, this practice is not recommended.

To change range the vehicle speed must be reduced to below 5 mph (8 km/h). Move the gear selector to neutral and then across the H-gate into the neutral position in the selected range. The appropriate LED illuminations on the selected range side of the selector cover will flash and an audible warning will sound. The flashing LED's and the audible warning will continue while the ratio control motor is moving the transfer box to the selected range.

When the ratio control motor has moved the transfer box into the selected range the LED's will stop flashing, the audible warning will stop and a message is displayed in the message center. The desired gear can be selected and the vehicle can be driven as required.

If the vehicle is moving above 5 mph (8 km/h) or the selector lever is moved into gear before the range change is complete, the change will not occur and a 'SLOW DOWN' or 'SELECT NEUTRAL' message will be displayed in the message center.

NOTE: The 'SLOW DOWN' message is generated by the BeCM, not the transfer box ECU.

The transfer box can be placed in the 'Neutral' position by moving the selector lever into the 'PARK, position. Insert a spare fuse (minimum 5 Amp) into fuse position 11 on the BeCM. After 5 seconds the transfer box moves to the neutral position, an audible warning will sound, a 'TRANSFER NEUTRAL' message is displayed in the message center and the high and low LED illumination on the selector cover will extinguish.

Range information - Automatic transmission

High range
When the transfer box is in high range the message center only displays the selected gear and the high range side of the selector lever cover is illuminated in green.

High to low range
When a change from high to low range is requested:
^ The low range selector cover LED's flash in orange
^ The high range selector cover LED's remain illuminated in green
^ The transfer box amber warning lamp in the instrument pack flashes while the range change is taking place.
When the range change is complete:
^ The low range selector cover LED's are continuously illuminated in orange
^ The high range selector cover green LED illumination goes off
^ The transfer box warning lamp goes off
^ The message center displays 'LOW' and after several seconds displays 'L' in front of the selected gear.

Low to high range
When a change from low to high range is requested:
^ The high range selector cover LED's flash in green
^ The low range selector cover LED's remain illuminated in orange
^ The transfer box warning lamp in the instrument pack flashes while the range change is taking place.
When the range change is complete:
^ The high range selector cover LED's are continuously illuminated in green
^ The low range selector cover orange LED illumination goes off
^ The transfer box warning lamp goes off
^ The message center displays 'HIGH' for several seconds, then 'HIGH' is removed and only the selected gear is displayed.

Range selection parameters incorrect
If a range change is requested and the vehicle speed is too high:
^ The LED illumination on the selected side of the cover will flash
^ A 'SLOW DOWN' message is displayed in the message center
^ The transfer box warning lamp in the instrument pack flashes.
If a range change is requested and the selector lever is moved before the range change is complete:
^ The LED illumination on the selected side of the cover will flash
^ A 'SELECT NEUTRAL' message is displayed in the message center
^ The BeCM will initiate an audible warning
^ The transfer box warning lamp in the instrument pack flashes.

Transfer box to neutral
When a spare fuse (5 Amp minimum) is inserted in BeCM fuse position 11 to select transfer box neutral:
^ A five second delay is initiated before the transfer box moves to neutral
^ The BeCM initiates an audible warning
^ A 'TRANSFER NEUTRAL' message is displayed in the message center.

WITH MANUAL TRANSMISSION

Range Change
To change from high to low the vehicle speed must be below 5 mph (8 km/h) or from low to high the vehicle speed must be below 15 mph (24 km/h).

Select neutral with the gear lever and press the high/low switch on the fascia. The indicator lamp on the switch will flash as the range change takes place. If the change is from high to low the lamp will continuously illuminate when the change is successfully completed. If the change is from low to high the lamp will extinguish when the change is complete. The message center displays the selected range.

If a range change is requested and the vehicle is moving too fast or neutral has not been selected, the indicator lamp on the switch will flash and a 'SLOW DOWN' or 'SELECT NEUTRAL' message will appear in the message center.

NOTE: The 'SLOW DOWN' message is generated by the BeCM, not the transfer box ECU.

The transfer box can be placed in the 'Neutral' position by placing the gear lever in neutral and inserting a spare fuse (minimum 5 Amp) into fuse position 11 on the BeCM. After 5 seconds the transfer box moves to neutral, an audible warning will sound and a 'TRANSFER NEUTRAL' message is displayed in the message center.

Range information- Manual transmission

High range
When the transfer box is in high range, the message center does not display any transmission information and the high/low request switch indicator lamp is off.

High to low range
When a change from high to low is requested:
^ The high/low switch indicator lamp flashes
^ The transfer box warning lamp in the instrument pack flashes.
When the range change is complete:
^ The high/low switch indicator lamp is illuminated continuously
^ The transfer box warning lamp goes off
^ A 'LOW' message is continuously displayed in the message center.

Low to high range
When a change from low to high range is requested:
^ The high/low switch indicator lamp flashes
^ The transfer box warning lamp in the instrument pack flashes.
When the range change is complete:
^ The high/low switch indicator lamp goes off
^ The transfer box warning lamp goes off
^ The message center displays 'HIGH' for several seconds.

Range selection parameters incorrect
If a range change is requested and the vehicle speed is too high:
^ The high/low switch indicator lamp will flash
^ The transfer box warning lamp in the instrument pack will flash
^ A 'SLOW DOWN' message is displayed in the message center.
If a range change is requested and the transmission is in gear or a gear selected before range change is complete:
^ The high/low switch indicator lamp will flash
^ The transfer box warning lamp in the instrument pack will flash
^ A 'SELECT NEUTRAL' message is displayed in the message center for several seconds. If the vehicle remains in gear the message will not be repeated.

Transfer box to neutral
When a spare fuse (5 Amp minimum) is inserted in BeCM fuse position 11 to select transfer box neutral:
^ A five second delay is initiated before the transfer box moves to neutral
^ The BeCM initiates an audible warning
^ A 'TRANSFER NEUTRAL' message is displayed in the message center.