Jeep offers a variety of four-wheel-drive systems for buyers of the new 2021 Grand Cherokee L to choose from. Called Quadra-Trac I, Quadra-Trac II, and Quadra-Drive II, each setup offers different levels of four-wheel-drive capability. Let’s take a quick look at how each system works and the differences between them.
Jeep Quadra-Trac I
Quadra-Trac I is a single-speed full-time four-wheel-drive system that requires no driver intervention. Four-wheel-drive is always engaged, with 48 percent of the engine’s torque delivered to the front axle and 52 percent going to the rear. Quadra-Trac I uses open differentials and relies on the traction control system to distribute power by way of the SUV’s brakes. If a wheel loses traction, the system senses the wheelspin and applies the brake to that wheel.
Quadra-Trac I uses the New Venture Gear NV140 transfer case. It has no low range or two-wheel-drive mode, so there is no shift lever or button. 2021 Grand Cherokee L Laredo and Limited models are equipped with the Quadra-Trac I system.
Jeep Quadra-Trac II
The Quadra-Trac II system uses the NV245 transfer case, which adds an electronically-controlled clutch pack to the center differential. Like Quadra-Trac I, this system sends 48 percent of the engine’s torque to the front axle and 52 percent to the rear, but unlike its simpler sibling, the clutch pack can change that ratio, sending up to 100 percent of the engine’s twist to either axle. Several sensors detect wheel slip and shift power forward or rearward as needed. As in the Quadra-Trac I system, Quadra-Trac II features open differentials and a brake-based traction control system.
Quadra-Trac II also has a low range with 2.72:1 gearing for more severe off-roading; hill-descent control, which keeps the vehicle at a constant speed on steep off-road descents; and a neutral range which allows the Grand Cherokee L to be towed on all four wheels without disconnecting the drive axles. Quadra-Trac II is the standard four-wheel-drive system on the 2021 Jeep Grand Cherokee L Overland.
Jeep Quadra-Drive II
Jeep’s top-of-the-line Quadra-Drive II four-wheel-drive system uses the same NV245 transfer case as the Quadra-Trac II setup and adds electronically operated limited-slip differentials to both front and rear axles. Each LSD has its own clutch pack, and if traction is lost at one wheel, power is shifted to the other. While Quadra-Trac II can shift power to the axle with the most traction, Quadra-Drive II can shift power to the wheel with the most traction, and therefore is less reliant on the braking system to arrest wheel-slip. Quadra-Drive II is also programmed to anticipate low-traction situations and make proactive adjustments.
Like Quadra-Trac II, Quadra-Drive II has user-selectable low and neutral ranges, as well as hill-descent control. Quadra-Trac II is standard on the top-of-the-line Grand Cherokee L Summit model and can be added to the Overland model as part of the Off-Road Group option package.
The post Quadra-What? Breaking Down the 2021 Grand Cherokee L’s 4WD Systems appeared first on MotorTrend.
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