There are a multitude of different diffs available for your Land Rover. Let's look at the difference between them.
Standard Open Differentials
A standard open differential allows drive to be transmitted to the wheels whilst also allowing them to travel at slightly different speeds when corning to improve handling and reduce tyre wear. Most vehicles are fitted with this type of differential as standard.
Plate Type Limited Slip Differentials
These differentials operate like a conventional open differential until wheel slip occurs. At this point the gears force spring loaded clutch plates to lock the centre of the differential up so it is completely locked. It will stay in this way until the torque on the wheel is removed. They are useful in that they lock the differential solid without any manual input from the driver and will do this based on a difference in the speed of the wheels alone. The disadvantage is that whilst they are locked handling will be compromised. Also, in the long term the clutches will wear.
Torsen Differentials
Torsen Differentials are more commonly known as Torque biasing Differentials. They use helical gear sets which limit the torque difference between the two wheels. So, if a wheel starts to lose grip instead of all the torque being transferred to that wheel via the path of least resistance as it would in an open diff; in a Torsen diff it will still send torque to the wheel with grip as well. This allows for a gradual lock which allows for good handling and road manners with no input from the driver. The disadvantage of this design is that if one wheel loses grip completely or is in free air the differential will unlock because it needs to have some torque loading on both wheels. Examples of this type of differential are Detroit Truetrac and the Ashcroft Automatic Torque Biasing Differential.
Detroit Locker
The Detroit locker is very different to most designs in that it is locked solid as it’s default position. It will then unlock only when the forces of the differential speeds of both wheels cause it to unlock.
This has the advantage that when venturing onto a low grip surface you know that both wheels are going to be turning at the same speed right from the start without any further driver intervention but also that eventually when turning on tight corners it should still allow the differential to unlock. The disadvantage to this design is that it can be quite aggressive in it’s unlocking and locking. And handling can be compromised until sufficient drive shaft wind up is experienced to unlock the differential.
Selectable Lockers
This type of differential normally operates as a conventional open differential. When the driver envisages they are going to traverse some terrain when traction may be compromised; they manually lock the differential using either air, an electric solenoid or even a mechanical cable. These designs are useful in that in normal use they are essentially just a regular open differential with no clutches to wear out. But if the driver needs the wheels to be completely locked the vehicle can be stopped, the differential locked solid and the wheels will then always turn at the same speed. Examples of this type of differential are ARB Air Lockers, Ashcroft Air Lockers and E-Lockers.