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Quadra-Trac and Quadra-Drive

The Grand Cherokee's full-time all-wheel drive

Where Command-Trac is part-time (you engage and disengage it), Quadra-Trac is permanent all-wheel drive: it feeds both axles all the time, is pavement-safe, and sends drive where the grip is. It was the Grand Cherokee's signature system.

NP249 Quadra-Trac (ZJ)

In the ZJ, Quadra-Trac uses the NP249 case with a viscous coupling: in normal conditions it splits drive to both axles (with a slight rear bias) and, when a wheel slips, the silicone fluid in the coupling stiffens and transfers torque to the axle with grip. All automatic, no levers.

One detail: the early units (1993–1995) didn't lock the center differential in low range (4LO); the revised 1996-on version did, improving performance in rough terrain.

NV247 Quadra-Trac II / Quadra-Drive (WJ)

The Grand Cherokee WJ took the idea further. The NV247 Quadra-Trac II transfer case uses an electronically controlled progressive clutch pack; and in its top form, Quadra-Drive, it pairs with gerotor-based Vari-Lok differentials at both axles, able to send nearly all the torque to a single wheel with grip. For its day it was about as capable as it got without touching a button.

Specifications