Ford Kuga

 Service Manual

Rear Drive Axle/Differential » Rear Drive Axle and Differential (System Operation and Component Description)
Base pressure

The hydraulic fluid is drawn from the sump of the hydraulic system and directed through a filter. The feed pump pressurises the system and pumps hydraulic fluid into the pump plungers. This base pressure of 4 bar presses the rollers for the pump plungers against the cam disc. At the same time, hydraulic fluid flows into the working piston. This eliminates the play in the clutch plates. The Haldex clutch can respond quickly and distribute the torque within fractions of a second. The spring force in the pressure accumulator determines the base pressure of 4 bar and compensates pressure fluctuations. A compensating spring works in the opposite direction and prevents the plate discs becoming blocked by the force of the working piston. This restricts the transferable torque to approx. 7 Nm. This value can, however, deviate slightly due to temperature and/or the difference in speed between the input and output shafts.

General Information

Driving situations

Haldex clutch

Design of the 3rd generation Haldex clutch

Design of the multi-plate clutch

All-wheel drive control unit

Electric feed pump

Pressure control - 3rd generation Haldex clutch

Base pressure

Increased base pressure (preload)

Pressure build-up

Design of the 4th generation Haldex clutch

Pressure control - 4th generation Haldex clutch