[Bill F]

The Disco uses a Haldex system to control AWD functions and it's oil can be changed probably/maybe(?) at the same time as the transmission and rear axle.. Land Rover also has an Active drive line AWD on some models.

 

[Bill F]

Is the Haldex system incorporated into the transmission or rear differential? I would assume it’s not a separate device with separate fluids etc.

Separate device with separate fluids. Same system used on many AWD cars