The Quadra-Trac II 4 x 4 system gives owners the benefit of the NV245 active transfer case and BTCS. The transfer case is the same one used in the Quadra-Drive II system. It takes input from a variety of sensors to determine tire slip at the earliest possible moment and take corrective action. The system also uses Throttle Anticipate ñ sensing quick movement in throttle from a stop ñ and it takes steps to maximize traction before tire slippage even occurs.
Torque is transferred to the individual wheels as needed by the BTCS to maintain traction in changing road conditions. When the system senses tire slip, it modulates brake pressure to the slipping wheel, which directs torque to the tires with the best traction.
Quadra-Trac II features an electronic shift mechanism for ease-of-use. The transfer case also includes a neutral position for trouble-free towing behind another vehicle.
The Quadra-Drive II Jeep 4 x 4 system offers owners the ultimate in off-road capability. It combines the NV245 full-time transfer case with Electronic Limited Slip Differentials (ELSD) for best-in-class tractive performance. The system instantly detects tire slip and smoothly distributes engine torque to the tires with traction. In some cases, the vehicle will even anticipate low traction and adjust to proactively limit or eliminate slip
The heart of the system is the NV245 active transfer case. This transfer case includes a center differential coupled with an electronically controlled clutch pack, varying it from a completely open state to completely locked, and infinite possibilities in between. The 4-Low gear ratio is 2.72:1.
Quadra-Drive II features an electronic shift mechanism with a unique engagement lever. The lever is conveniently located on the shift console. Pulling the lever up engages 4-Low. The lever returns to a resting position after activation. The transfer case also includes a neutral position for trouble-free towing vehicles, such as behind a motor home.
A key component in the Quadra-Drive II system is the ELSD ñ an industry first application ñ and the new benchmark for automatic traction differentials. The ELSD use electronically controlled clutch packs to automatically and instantly vary from slip to lock at each axle. This maximizes traction when needed without any of the on-road drawbacks normally associated with such a robust 4 x 4 system.
All components of the system work together, continually monitoring needs, to provide smooth and automatic application of the components for best-in-class tractive performance while improving the day-to-day on-road driving experience. For example, the ELSD releases the clutch packs in the front axle during turns to allow differentiation and prevent crow hop.
This site has a lot of info