4x4 SYSTEMS BY VEHICLE
The Rock-Trac transfer case is the heart of Wrangler Rubicon's extreme rock crawling ability. Because of the 4:1 low-gear ratio, Rock-Trac's low crawl speed makes it easy to ascend or descend sharp inclines and to crawl over obstacles. Rock-Trac also features a fixed-yoke output assembly, usually only available as on after-market option. And best of all, it carries the full manufacturer's warranty.
This legendary part-time system has served Jeep owners well through the years. Command-Trac is a proven shift-on-the-fly system with a 2.72:1 Low-Range and Neutral.
Command-Trac II® supports the new MP 1522 two-speed, part-time four-wheel drive transfer case, featuring smooth operation, shift-on-the-fly capability, and improved NVH control compared to systems with mechanical linkage. 2WD High is the usual driving mode, with the front driveline disengaged from the transfer case and power directed to the rear wheels. Selecting 4WD Lock via the electronic, console-mounted switch locks the front and rear driveshafts together; the two then rotate at the same speed and provide a 50 front/50 rear torque split, providing better traction on slippery surfaces. This transfer case allows for 2WD, 4WD high-range and low-range as well as neutral.
Selec-Trac II supports the new MP 3022 two-speed, full-time active “on-demand” four-wheel drive transfer case. When driving in 4WD Auto mode, the transfer case clutch pack detects wheel slip and applies increased or decreased torque between the front and rear axles based on real-time driving conditions, thus optimizing traction. Under the right conditions, the vehicle can be driven by just one wheel. For added capability when traversing steep grades, rough terrain, or extremely poor tractions surfaces, the transfer case includes a 4WD Low mode. Electronic shifting between 4WD Auto and 4WD is accomplished via a console-mounted switch. A 2WD mode is also provided for some markets.
Quadra Drive II®
Quadra-Drive II's active full-time 4Wd system is the ultimate for virtually any driving situation. This system uses the Quadra-Trac transfer case and Electronic Limited Slip Differentials in rear axle offering excellent tractive performance. Quadra-Drive II also featured a 2.72 LOW-RANGE and NEUTRAL.
The brilliance of this 4WD system is it's simplicity. Quadra-Trac I operates in a high-range, all-time mode delivering optimum traction in virtually any driving situation with no driver input required.
This active full-time system functions in all-wheel-drive until additional traction is needed, then reacts by electronically engaging the clutch pack to transfer up to 100% of the torque to either axle. This system also features 2.72:1 LOW-RANGE and NEUTRAL.
Jeep® Compass models with a 5-speed manual transaxle or continuously variable transmission feature selectable four-wheel-drive lock. This state-of-the-art electronic system anticipates the need for added traction and responds to wheel-slippage by transferring power to the rear wheels, while modulating rear-wheel to contribute to vehicle stability in cornering situations. The system also saves fuel by operating only on demand when on-road, thereby minimizing power-robbing friction and inertia. Activate the off-road mode by pulling up on the chrome T-handle switch labeled 4WD LOCK in the center console. This mode dictates that the electronic sends the maximum amount of torque to the rear axle for improved traction.
An electronically controlled coupling, which is attached to the rear differential, is the heart of the Freedom Drive II system. The electronic control module processes signals from the wheel speed sensors and the accelerator pedal to determine how much torque to transfer to the rear wheels, then sends an electrical current to the ECC that is proportional to the amount of torque required. Recommended for true off-road situations including steep grades, wheel lift and rock or log climbing, the Freedom Drive II Off-Road Package includes a second-generation continuously variable transaxle with a 19:1 crawl ratio (CVT2L) that engages when the off-road mode is activated.