Optimising the Centre Diff Lock (CDL)

Many D2s have a centre diff lock, but no operating mechanism. Trevor Cuthbert shows two ways to gain control

Adding CDL capability to a Discovery 2 to unlock more off-road potential

When Land Rover launched Discovery 2 in 1998 it was equipped with anti-lock brakes (ABS) and electronic traction control as standard. Hill Descent Control is also a feature of Discovery 2. Such was the quality and capability of these systems, Land Rover decided that a centre differential lock was no longer necessary for the type of work a Discovery 2 would do. It was a controversial decision at the time, but the traction control system does work very well. However, the transfer gearbox fitted to these early Discovery 2 models still had CDL capability; it simply lacked an operating mechanism. Later vehicles had the capability removed from the transfer gearbox as a cost-cutting measure. And then, just to confuse matters, the capability was re-introduced to late models, so that CDL could be offered as a factory option.

Confusing and indecisive, but to conclusively check if your Discovery 2 has CDL capability, whatever its vintage, look at the serial number at the back of your transfer gearbox. If the serial number is prefixed with 41D or 42D, it has CDL capability. This means that all you need to do is to fit one of the linkage options outlined in this feature, to add CDL capability. However, if the serial number starts with 61D, 62D, 69D or 70D you would either have to change the transfer gearbox, or fit the internal parts offered by Ashcroft Transmissions to convert it – as well as adding a shifting mechanism.