Dodge / Ram
Future: 2018 Jeep Wrangler • 2019 Scrambler Pickup
Looking for all of Allpar’s Jeep pages in one spot? You’ve reached the right place!
We have divided up the Jeep line into “current Jeeps” (the ones they still make), Jeeps of the Past, and Jeeps by Year and Category (which is where you will find some of the vintage years). We also have concept cars and shows.
Jeep J8: the paramilitary/NGO Wrangler made in Egypt
Where did it all start? Bantam and Willys Jeeps • Jeep MA and MB
Gladiator / J-Series Pickups 1963-87
Scrambler pickup (1981-85 CJ-8): Unpopular at first, then sought-after CJ-based pickup
Cherokee XJ (1984-2001)
Jeep Cherokee police cars: the surprisingly popular and effective predecessors of today’s “police utilities”
Earthroamer RV: Jeep-based go-anywhere RV
The first Jeep Wrangler: 1997-2006
The first Wrangler JK: 2007-2010
Jeepster: 1948-50, 1966-73, and concept cars
Jeep Commander: stretched Grand Cherokee
Willys and Kaiser-Jeep in Brazil
Launched in 1999 on the Jeep Grand Cherokee, the Quadra-Trac II transfer case normally sent most power to the rear wheels. When a wheel lost traction, a gerotor pump increased hydraulic pressure on a multi-disc clutch pack, sending power to the front axle.
The pump used a rotor driven by the front drive shaft and the case by the rear drive shaft, increasing pressure to the clutch pack in proportion to their speed variation. Clutch discs were alternately splined to the front and rear drive shafts. Because Quadra-Trac II could immediately pressurize the clutch pack, it had a faster response than a normal viscous coupling. (Quadra-Trac II's low range had a 2.72:1 torque ratio and fully locked the center differential).
A similar pump was incorporated in the Vari-Lok differential; power transfer was proportional to wheel speed difference rather than torque difference. By avoiding the need to pre-load the differential to assure torque transfer (which causes wear in normal use), Vari-Lok could be virtually wear-free. Again, Vari-Lok differentials were faster and smoother than viscous systems, and the pump response could be precisely tuned to driving conditions, enabling the use of this system in the front axle as well as the rear.
Buying a used Jeep
Related Jeep Wrangler pages
Inside the Wrangler
Variants and related...
The 2018 Jeep Wrangler JL: suspension • aluminum vs steel • open or fixed roof • pickup
body engineering • weight, strength, and safety • transmissions • engines
All Mopar Car and Truck News