Haldex Generation IV is an electronically controllable all-wheel drive coupling for cars. The Haldex GenIV includes an electronic control unit with vehicle dynamics software that can be customized to meet each carmaker's particular desires in terms of driving characteristics.
The front and rear axle of the car are connected via the wet multi-plate clutch which makes it possible to vary the torque distribution between the two axles. As the function of the Haldex GenIV is independent of the differential speed between the front and rear axle, full locking torque, if needed, is available at any given time and speed.
When starting the vehicle, the electrical pump in the Haldex GenIV is started, swiftly providing the system with pressurized oil and thereby making the system ready for operation. The control valve sets the pressure to the piston which in turn compresses the disc package. The level of pressure set depends on the torque level needed and the driving situation. In traction/high slip conditions, high pressure is delivered. In tight curves (e.g., parking) or at high speeds, a much lower pressure is provided.