Driven Wheels: An in-depth look at Jeep’s 4×4 systems

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When talk turns to the most capable four-wheel-drive systems in new vehicles today, Jeep is often the first brand that comes to mind. The variety of options available on, and capability of, each of its models makes Jeep the default choice for many off-road enthusiasts.

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Every Jeep sold in Canada today comes with four-wheel-drive (4WD), and most also come with hill-descent control. From there, however, the functionality of Jeep’s different systems can vary dramatically. Some are designed to set drivers on the path to water-fording and rock-crawling; while others are better suited to providing added security across a variety of road surfaces and weather conditions.

To help you make the right decision about which system is right for you, we’ve dug into the details of each Jeep 4×4 system, simplified the terminology for those who aren’t hardcore off-roaders, and listed everything in one place below.

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Jeep’s Entry-level Active Drive 4×4 Systems

Jeep’s Active Drive systems are offered on the Jeep Renegade, Jeep Compass, and Jeep Cherokee.

Jeep Active Drive 4×4

Jeep’s entry-level 4WD system is Active Drive 4×4, which in Canada is standard on both Compass and Renegade as of 2023. Jeep says this system covers the basics for everyday driving. It disconnects the rear axle by default, so that the engine only powers the front wheels, which improves fuel efficiency in low-demand conditions. When a loss of traction is detected at the front axle, the rear wheels engage with no input required from the driver.

How much torque goes to each axle depends on the setting chosen with the Selec-Terrain traction management system, which has four modes: Auto, Snow, Sand, and Mud. For example, Auto mode attempts to maintain a front-to-rear torque split of up to 40-60 per cent, while the Sand or Mud modes can send up to 100 per cent of torque to the rear as needed.

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This system uses a brake-lock differential, which combines the anti-lock brakes and traction control systems to apply brake pressure to a wheel that’s spinning. This increases the torque that’s required to turn it, which increases the torque going to the axle’s other wheel to give it the traction that’s necessary to move.

Jeep Active Drive Low 4×4

This upgrade to the Active Drive system is offered on the Compass Trailhawk, Renegade Trailhawk, and Renegade Trailhawk Elite trims. It adds a transfer case and a 4 Low mode. With this system, Jeep publishes crawl ratios: these explain the gearing that’s installed for low-speed off-road manoeuvring, numbers calculated by multiplying the shortest transmission gear ratio (first gear) by the low-range gear ratio and the axle ratio.

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The Active Drive Low 4×4 system adds a 20:1 crawl ratio to Compass Trailhawk; and a 21:1 ratio to Renegade Trailhawk and Trailhawk Elite, which are relatively low crawl ratios best suited to rougher roads and light trails, as opposed to serious rock-climbing or water-fording. With this upgrade, the Selec-Terrain system adds a fifth drive mode, for Rock.

Jeep Cherokee’s Active Drive 4×4 systems

The Jeep Cherokee also comes equipped with versions of the brand’s Active Drive 4×4 systems, but the capabilities are slightly different.

Jeep Active Drive I 4×4

In Canada, this system is standard on the Cherokee Altitude—note that for 2023, Cherokee is down to two trims in Canada, Altitude and Trailhawk—and operates identically to the Active Drive 4×4 system as explained above.

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Jeep Active Drive Lock 4×4

This system is the default for the Cherokee Trailhawk. This does everything the Active Drive Low 4×4 system does as explained above, and adds additional capability. A rear axle locker is equipped, which forces both axles to stay engaged full-time. In addition to hill-descent control, a hill-ascent system for speed-controlled climbing is included here.

The crawl ratio on the Cherokee Trailhawk is 51:1, which allows for more capability than the system found on the Renegade and Compass, and can tackle more challenging back roads and trails. Active Drive Lock 4×4 also adds a Neutral mode, which fully disconnects the engine and transmission from the rest of the driveline so that the Cherokee can be flat-towed behind another vehicle, such as an RV.

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Jeep’s Premium Quadra- 4×4 Systems

The latest premium Jeep vehicles—including the fifth-generation Jeep Grand Cherokee and Jeep Grand Cherokee L, as well as the new Wagoneer and Grand Wagoneer—are fitted with Jeep’s Quadra-Trac and Quadra-Drive 4×4 systems. All three systems are equipped with an active transfer case, which sends power directly to the wheel with the most grip to improve traction as required.

Quadra-Trac I

Standard on Grand Cherokee and Wagoneer Series II in Canada, this system provides full-time 4WD with no driver interaction required, operating with a slight rear bias at a 48-52 torque split. It equips a single-speed, high-range-only transfer case. Torque is distributed via a brake-lock differential, as explained in the section on Jeep’s Active Drive 4×4 system above.

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Quadra-Trac II

This system is equipped on the Jeep Grand Cherokee Overland and the Wagoneer Series III. It uses the same brake-based traction control as Quadra-Trac I and the same default torque split, though this system offers more flexibility in distributing torque front-to-rear on demand. This is due to a more sophisticated transfer case, and an electronically controlled clutch pack for the centre differential, which allows up to 100 per cent of engine power to be sent to either axle at any time on demand. All of this takes place automatically in 4WD Auto mode with no driver intervention.

An electronic shifter allows the driver to move into and out of 4 Low by pressing a button at speeds up to 40 km/h. This system also adds a Neutral position for flat-towing.

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Quadra-Drive II

This is the most sophisticated system available on the Jeep Grand Cherokee and Wagoneer lines, where it can be found on the Jeep Grand Cherokee Trailhawk and Summit or Summit Reserve, as well as the Grand Wagoneer. Quadra-Drive II adds a front and rear electronic limited-slip differential (ELSD), which is an upgrade from the brake-based system that allows up to 100 per cent of available power to be pushed directly to an individual wheel as required to optimize grip. A Neutral position for flat-towing is also included.

Jeep Wrangler and Gladiator’s -Trac 4×4 Systems

Below, you’ll find the details on the 4WD systems available with Jeep’s most capable off-roaders. All of these systems include Neutral mode for flat-towing.

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Command-Trac

This is the standard 4WD system for most Wrangler and Gladiator models. It includes manual shift-on-the-fly between 2WD to 4WD modes at speeds of up to 88 km/h. In 4WD, the torque split is 50-50, front to rear. Torque is distributed via a brake-lock differential, which works as described above. Vehicles equipped with Command-Trac ship with solid front and rear axles. A manual transfer case facilitates shifting into 4 Low from a stop, which locks the front and rear driveshafts and pushes power through another set of gears, multiplying torque to 2.72:1. Jeep has not provided a crawl ratio for this 4WD system.

Rock-Trac

This is the system that comes with Rubicon models. It adds a part-time transfer case with a 4:1 ratio in 4 Low mode, which delivers a factory-spec 73.1:1 crawl ratio with the manual transmission. This crawl ratio gets into serious off-roading territory: Jeep says it allows for a controlled 1-km/h cruise up the rocks.

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Tru-Lok locking front and rear differentials are equipped, which can be used in only in 4 Low mode. Rock-Trac also comes with an electronic sway bar disconnect system, which stiffens the suspension on demand to improve stability and reduce the risk of rollover. Rubicon models allow sway-bar disconnect at speeds under 30 km/h in 4 Low mode to allow for improved suspension articulation.

Selec-Trac

Offered on the Wrangler Rubicon 392, Selec-Trac offers a slightly more road-friendly 4WD option. This adds a full-time transfer case with a 2.72:1 low range. The 2 High mode on the Rock-Trac system is swapped for 4 Auto mode, which switches automatically between 2WD and 4WD without driver input for improved on-road efficiency.

Plug-in hybrids

The 4WD systems offered in the Wrangler 4xe PHEV, which include Selec-Trac and Rock-Trac, are functionally the same as in Wrangler gas models. Jeep’s engineering department says there are some minor hardware differences to accommodate the eight-speed automatic transmission found in the Wrangler 4xe, which is a different eight-speed automatic than the one equipped in gas models.