How 4x4 Systems Work
Rock-Trac®
- 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. Standard on: Wrangler Rubicon and Wrangler Unlimited Rubicon.
Command-Trac ™
- This legendary part-time system has served Jeep® owners well through the years. Command-Trac is a proven shift-on-the-fly system with 2.72:1 Low-Range and Neutral. Standard on: Wrangler Sport, Wrangler Sahara, Wrangler Unlimited Sport and Wrangler Unlimited Sahara.
Command-Trac II™
- Command-Trac II supports a two-speed, part-time four-wheel-drive transfer case. 2WD 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. Standard on all Liberty models.
Selec-Trac II™
- Selec-Trac II™ supports a two-speed, full-time active "on-demand" four-wheel-drive transfer case. When driving in 4WD Auto mode, the transfer case clutch pack can detect wheel slippage and instantly apply 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 traction surfaces, the transfer case includes a 4WD Low mode. Electronic shifting between 4WD Auto and 4WD Low is accomplished via a console-mounted switch. A 2WD mode is also provided. Optional on all Liberty models.
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 II transfer case and Electronic Limited Slip Differentials in both axles, offering excellent tractive performance. Quadra-Drive II also features 2.72 LOW-RANGE and NEUTRAL. Optional on Grand Cherokee North Edition/Limited, Commander Sport/Limited.
Quadra-Trac I™
- The brilliance of this 4WD system is its 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.
- NOTE: The Grand Cherokee SRT8 uses an on-demand system that drives the rear driveshaft and engages the front driveshaft when needed, either when slip is sensed, or with throttle anticipation, which engages the front prior to slip when throttle is applied. Standard on: Grand Cherokee North Edition/Limited and Commander Sport.
Quadra-Trac II™
- 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. Standard on: Commander Limited. Optional on: Grand Cherokee North Edition, Limited and Commander Sport.
Freedom-Drive I™
- Jeep Compass 4x4 models with a five-speed manual transmission or Continuously Variable Transmission feature standard Freedom-Drive I. This state-of-the-art electronic system anticipates the need for added traction and responds to wheel slippage or accelerator pedal position by transferring power to the rear wheels, while modulating rear wheels 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. A 4WD LOCK mode, providing a locked 50/50 torque split between front and rear at low speeds for severe road or trail conditions is activated by pulling up on the chrome T-handle switch labelled 4WD LOCK in the centre console. Standard on Compass and Patriot 4x4.
Freedom-Drive II™
- An electronically controlled coupling, forward of the rear differential, is the heart of the Freedom-Drive I and II systems. 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.
- A 4WD LOCK mode, providing a locked 50/50 torque split between front and rear (at low speeds) for severe road or trail conditions is activated with a T-handle switch labelled 4WD LOCK in the centre console. 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 Transmission (CVT2L) with a 19:1 crawl ratio that engages when the off-road mode is activated. Optional, with the Trail Rated Off-Road Group on Patriot 4x4.
