Disco II Diffs & Traction Control
Hi Roverash,
Disco II Diffs are similar to earlier Disco Diffs in the way they operate. In the Disco II with traction control Land Rover did away with the Diff lock position on the Low - High transfer gear lever. The idea being that the traction control would do the job without the driver having to touch anything.
To understad how it works you need to understand the Land Rover 4 wheel drive system. Basically with an earlier Disco if centre diff lock was not engaged you only needed one of the four wheels to lose traction to be stuck in the mud.
Engaging the centre diff lock would block the front propeller with the rear propeller shaft. In this position the vehicle would move forward or backward if the left and right hand wheels on the front or rear axles had traction. However if you lost traction on one front wheel and one rear wheel you would be again stuck in the mud.
Disci II did away with the centre diff lock lever position. Using the ABS system to compare the speed of rotation of the four wheels. When the electronic system picked up a difference in wheel speed, (a wheel loosing traction will turn faster) When this condition happens, the ABS system will apply the brakes to that spinning wheel and only to the spining wheel or wheels. In doing this it allows more torque to the wheel or wheels with traction and therefore allows the vehicle to continue moving. In this way it is an improvement over the old system.
The ABS system with traction control and hill decent control are very usefull in offroad and poor road conditions. However we do have some owners here that use their Disco II in extream conditions. For these people we have modified their vehicles so the centre diff can be locked because they would experence brake fade with the extra heat generated when the traction control was in constant use.
I hope this answeres your question.
Cheers,
Graeme.