4Drive is a full-time four-wheel drive system developed for Seat cars. It prevents even minimal wheel slippage in difficult road conditions. The system increases the vehicle’s stability and ensures reliable road grip. It has been used on the Ateca, Alhambra, Altea, and Leon models.
How 4Drive works
The system uses data from the ABS and ESP sensors about the wheel speed, lateral and longitudinal acceleration, and yaw rate. It also interacts with the engine control unit and the gearbox. Based on the received data, the driving mode is immediately adapted to suit the road conditions.
Torque is supplied via a propeller shaft to a 5th generation Haldex clutch. It acts as a centre differential and distributes power between the axles. The axle with better road traction receives more torque.
Disadvantages of 4Drive
- The friction clutch can overheat, which leads to it failing;
- The clutch bearings wear out fast;
- High system maintenance costs;
- The transmission fluid must be frequently replaced;
- The system control unit can fail prematurely due to corrosion.