Range Rover 4.0/4.6
Range Rover 4.0/4.6
Introduction
A Borg Warner 44-62 transfer gearbox is installed in 4.0/4.6 Range Rovers.
Like the Borg Warner unit used in Classic since 1989, this transfer box includes a quiet running Morse Chain, planetary high/low gearset, center differential and viscous coupling.
Unlike the original, it also includes an electronically controlled electric shift motor linked in with the new H gate automatic transmission shifter. In addition, the location of the planetary gearset and Morse Chain has been altered to allow for the electric shift feature.
Electronic Operation
Inputs include power, ground, vehicle speed, gear selector position and BeCM information. Outputs include the high/low status lamps on the shift quadrant, message center information and operation and the shift motor. Cruise control is locked out during low range operation.
Controlling the high/low shift is an ECU located underneath the drivers seat. Whenever the shift lever is moved from the high to low (or low to high) position in the neutral gate, the ECU makes the decision whether or not the electric shift motor will operate.
Towing Precautions
When flat towing a new Range Rover it is necessary to place the transfer gearbox in its neutral position, and select PARK on the automatic transmission shift lever. Since the shift is electrically controlled, a special procedure is needed to select transfer gearbox neutral:
1. Switch off ignition.
2. Insert a 5 amp fuse into position 11 of the BeCM fuse box (see illustration).
3. Insert key and switch on ignition - message center will indicate transfer neutral.
4. Remove the fuse for normal gearbox operation after towing.
Service Information
Oil Type: ATF Dexron II,III
Quantity: 2.5Q (2.4L)
Gear Ratios: High 1.22:1 Low 3.27:1
Service Interval
Under normal conditions, the new Range Rover transfer box should be drained and refilled every 30,000 miles (48,000km). If used extensively off-road, this service should be performed every 15,000 miles (24,000km).
T4
T4 is the primary tool for diagnosing faults in the transfer gearbox electrical/electronic systems. To access, select the "Transfer box" icon from the main diagnostic menu.