General Introduction

Range Rover 4.0/4.6 Borg Warner Transfer Box

General Introduction
The Borg Warner transfer gearbox incorporates a single epicyclic gear set which is driven by the main gearbox output shaft to provide high, neutral or low gear ratios.

With high or low gear selected, power is transmitted by a Morse Chain to the front and rear output shafts via a differential and a limited slip viscous unit. The gear lever allows neutral, high or low to be selected. A differential lock is not necessary as this function is automatically performed by the viscous coupling unit.

Lubrication is by a low pressure plunger type oil pump, driven by the epicyclic gear set. Oil is delivered to the gears and bearings via oilways in the components.

The viscous coupling though partly immersed in lubricating oil, is a self contained and sealed unit. Illustration 41M7057, showing the component parts of the transfer box, is a useful cross reference when studying the following power flow diagrams.