Part 4

Four-Wheel Drive Systems - 4.2L/4.4L (Part 4)

SERVICE

Basic Dimensions (Millimeters)

Basic Dimensions (Millimeters):

The transfer box weighs 40.30 kg without oil and 41.55 kg with oil. The unit requires 1500 ml ± 2% of oil from empty (dry).

The oil used in the transfer box is Shell TF 0753, which has been specially developed by Magna Steyr and Shell. The oil contains unique additives, which enhance the transfer box operation. No other oil must be used in the transfer box.

There is a unique type of grease, Weicon anti-seize montagepaste grau TL 7391, that needs to be applied to the units input shaft spline when installing or reinstalling the transfer box.








DIAGNOSTICS
The transfer box control module can store fault codes, which can be retrieved using T4 or a diagnostic tool using KW2000^protocol.

The information is communicated via a diagnostic socket.

The diagnostic socket allows the exchange of information between the various control modules on the bus systems and T4 or another suitable diagnostic tool. The information is communicated to the socket via the CAN bus. This allows the retrieval of diagnostic information and programming of certain functions using T4 or another suitable diagnostic tool.

The transfer box control module uses Diagnostic Trouble Codes (DTC), which relate to transfer box electrical faults.

Clutch and Range Change Mechanism Calibration
In order for the range change mechanism to function correctly, the transfer box control module must be calibrated to the mechanical dimensions of the transfer box that it is connected to.

This procedure is required if one of these occurs:
^ The switch is changed
^ The transfer box control module is changed
^ The transfer box or range position sensor is changed
^ Vehicle or transfer box control module fault has caused the transfer box to revert to an undefined range.

Calibration can be carried out using T4.

SYSTEM OPERATION
The selection of high/low range is achieved by using a switch located behind the main transmission selection lever in the center console. A range change can only be performed when the transmission selector lever is in neutral (position 'N').

The accelerator pedal must not be depressed when a range change is in progress.

If high or low range is requested and the transmission selector lever is in a position other than 'N' or 'P', the instrument cluster message center will display 'SELECT NEUTRAL FOR RANGE CHANGE'.

NOTE: If the transmission selector lever is in the 'P' position, the range change will not take place and the 'SELECT NEUTRAL FOR RANGE CHANGE' message will not be displayed in the message center.

When low range is selected, the low range 'mountain' symbol will flash when the range change is taking place and then remain illuminated when the range change is complete. The instrument cluster message center will display 'LOW RANGE SELECTED' for approximately 3 seconds followed by a chime from the instrument cluster to confirm that the range change has been completed. Only 'D' and 'Manual mode' are available, the 'Sport mode' selection is not available.

When high range is selected, the low range 'mountain' symbol will flash when the range change is taking place and then extinguish when the range change is complete. The instrument cluster message center will display 'HIGH RANGE SELECTED' for approximately 3 seconds followed by a chime from the instrument cluster to confirm that the range change has been completed.

The design of the transfer box allows range changes when the vehicle is moving, within set limitations as follows:
^ High to Low - at speeds not exceeding 25 mph (40 km/h)
^ Low to High - at speeds not exceeding 37 mph (60 km/h).

If the vehicle speed is higher than the parameters given, the instrument cluster message center will display 'SPEED TOO HIGH FOR RANGE CHANGE'. When the correct speed range is reached, the message will be deleted and the range change will commence.

The transfer box control module interprets a road speed of less than 2 mph (3 km/h) as a static shift (vehicle not moving).

In this instance, the driver must use the shift lock procedure of operating the brake pedal to allow the selector lever to be moved from 'N' to 'D' after the range change has been performed.

High range should be used for all normal road driving and also for off-road driving across dry, level terrain. Low range should only be required where low speed maneuvering is necessary, such as reversing a trailer, negotiating steep slippery surfaces or boulder-strewn terrain. Low range should also be used for extreme off-road conditions where progress in high range cannot be maintained. Low range should never be used for normal road driving.

HIGH RANGE OPERATION
In high range, the torque input from the transmission is passed to the transfer box input shaft. The position of the synchronizer sleeve couples the shaft directly to the differential housing. The differential splits the torque between the two side gears. One side gear is connected by splines and passes the torque to the rear output flange. The second side gear is connected to the chain drive sprocket and passes the torque, via the chain, to the front output flange.

LOW RANGE OPERATION
In low range, the torque input from the transmission is passed to the transfer box input shaft. The synchronizer sleeve is moved and connects the planetary carrier to the differential housing. The torque from the transmission is now directed through the sun gear of the epicyclic gearset and, via the pinion gears and pinion gear shafts, into the planetary carrier. The annulus gear of the epicyclic gearset is secured inside the casing and generates the low range ratio of 2.93:1. The torque is then passed, via the synchronizer sleeve, to the differential housing where it is split between the two side gears. One side gear is connected by splines and passes the torque to the rear output flange. The second side gear is connected to the chain drive sprocket and passes the torque, via the chain, to the front output flange.

HIGH/LOW RANGE GEARS WITH SHIFT-ON-THE-MOVE
The driver is able to change between high and low range gears while the vehicle is moving, or if the vehicle is stationary.

Pushing the range change lever makes a range change requests. This lever is located on the center console behind and to one side of the main transmission lever. The driver requests a range change by pulling the range change lever towards the rear of the vehicle.

The driver is informed of the range status via a green lamp (mountain symbol) in the instrument. The lamp will not be illuminated in high range, illuminated in low range and flashes during a range change.

The driver is informed of the range status via a green lamp (mountain symbol) in the instrument cluster and LED's next to the range change lever. The lamp will not be illuminated in high range, illuminated in low range and flashes during a range change. There are two LED's on the range change lever one for high and one for low. During a range change the new range LED will flash.

The vehicle will remain in the selected range unless the driver requests a change, i.e. it will not automatically revert to high range following a key off/key on sequence.

RANGE CHANGE PROCEDURE
Neutral must be selected on the main transmission before requesting a range change and then select the appropriate gear following completion of the range change. During the range change the main transmission will be locked in neutral.

If neutral is not selected when a range change is requested then the request is denied and the driver will be advised to select neutral via the instrument cluster message center.

The range change process can take up to one second to complete following a request being accepted.

There is a limit set on the maximum speed at which a range change can be achieved. The maximum speed for a high to low range change is 25 mph (40 km/h). The maximum speed for a low to high range change is 37 mph (60 km/h). If the vehicle speed is over the limit when a range change is selected then the request is denied and the instrument cluster message center will display a 'SPEED TOO HIGH FOR RANGE CHANGE' message.

TRANSFER BOX CONTROL DIAGRAM

NOTE: A = Hardwired; D = CAN bus

TRANSFER BOX CONTROL DIAGRAM (PART 1):

TRANSFER BOX CONTROL DIAGRAM (PART 2):