Quadra-Drive
The Quadra-Drive system was introduced in 1999 and is based on the Quadra-Trac II system but adds limited slip differentials to the front and rear axles to create a four-wheel drive system capable of not only directing torque to the axle with best traction but to the individual wheel on an axle with best traction.
Read more about this topic: Jeep Four-wheel-drive Systems