The new-generation Jeep Grand Cherokee (WK) and '06 XK Commander have been panned by hardcore off-roaders as being too pavement-oriented because of their unibody construction and independent front suspensions. This vocal-minority grumbling didn't discourage Superlift from engineering lift systems for both 4WD and 2WD versions of these new Jeeps, because Superlift strives to have the widest range of lift systems and accessories in the off-roading industry.
Designed in cooperation with American Expedition Vehicles (see sidebar), the new Superlift 4-inch systems maintain these Jeep SUVs' tame on-road ride while improving their off-road potential. Ground clearance improves through creating space for up to 33x12.50 tires on 8.5-inch wheels with a maximum 5.75-inch backspacing (to retain the factory wheels, minimum 3/4-inch-thick spacers are required for knuckle clearance).
PartsSuperlift applies its Frame Integrated Technology (F.I.T.) IFS approach to the WK/XK kit. Key components are replacement ductile-iron steering knuckles with a stout bellypan/crossmember assembly. These knuckles and the high-clearance crossmember help relocate the differential (4x4 application only) and lower control arms to maintain factory geometry: CV axles, steering linkage, and wheel alignment stay within spec. The 4x4 version of the kit also addresses front driveline angles so that the factory driveshaft can be retained. Underneath, Superlift contours the kit's interlocking crossmember and full-width bellypan for maximum ground clearance, using countersunk fasteners. This subframe structure relocates the lower control arms and improves the WK/XK's overall stability.
Superlift enhances ride quality in the front by adding preload spacers and tower blocks to the stock coilover strut assemblies. The preload plates increase the spring rate slightly to minimize mushiness and compensate for the increased weight and offset created by larger tires and wheels. Extended factory-style front and rear antisway-bar links ensure proper bar preload to further tune the road ride.
In the rear, Superlift eliminates the inherent sponginess by using longer coils that have a slightly heavier rate than stock. The kit's relocation brackets maintain correct four-link geometry.
Customers can choose between two grades of rear shocks, both of which are valved specifically for the XK/WK: standard Superlift Superide hydraulics or premium Superide SSR remote-reservoir shocks, which are trick-looking, high-pressure monotube units.
In addition to shock choice, customers can also add optional eXtreme Ring differential cover protectors. These and all other Superlift components are covered by a limited lifetime warranty.
Note that if the Jeep is equipped with Electronic Stability Program (ESP), premature system engagement may occur after installing any lift system: ESP function is impacted by tire size, wheel offset, and other factors. If ESP routinely activates, the driver can disable the system by pushing the "off" button located in the center stack of the dash. ESP is also affected by steering-wheel position, and the system must be disabled with each key cycle if the steering wheel isn't centered. Superlift and AEV are working on an ESP recalibration system; check their websites for the latest information.
InstallationSpecialized tools and fabrication skills (4x4 system only) are required. Because of this, Superlift recommends that the job be performed by a qualified professional. The photos and captions here provide an overview of the process as performed on a 4x4 Grand Cherokee; the 4x2 kit deletes the front differential relocation parts and doesn't require the frame welding and exhaust clearancing.
Preparation involves applying pieces of tape to the steering wheel and column to mark their alignment. The steering wheel is recentered following the lift. It is also necessary to unbolt the rear track bar at the axle and disconnect the battery's negative cable before raising and securing the Jeep. Referring to a service manual while removing the OE skidplate, sway bars, brakes, knuckles, front axleshafts, struts, and other factory suspension components is a good idea. Superlift's comprehensive and well-illustrated instructions detail each step.
The end results: an even grander Grand and a Commander that might actually command some respect from crusty old off-roaders.
AEV Takes Jeeps to a Higher Level
American Expedition Vehicles (AEV) grabbed the Jeep world by the throat in the late '90s with its stretched-wheelbase Wrangler 112 concept vehicle. DaimlerChrysler took note of this and other AEV innovations such as integrated rocker-panel protection, subsequently making these features available off the assembly line. AEV has also won three DaimlerChrysler Design Excellence Awards for its custom Jeep vehicles.
In late 2004, AEV contacted Superlift for design assistance with its Mojave Grand Cherokee project. "We originally approached Superlift for a few reasons," says AEV founder Dave Harriton. "We knew the WK/XK platform would be a great seller if it were done right, so it made sense to invest in a high-quality suspension. Superlift was chosen because [they are] one of the few suspension companies to have all [their] own manufacturing in house. That makes prototype and development much easier and less expensive. Also, I had previously worked with Superlift's head engineer, Kevin Dill (who was responsible for the Atlas transfer case). Kevin really did a great job with the suspension, and we tested and tweaked it for over a year. Customers who purchase this lift are not going to tolerate poor handling, poor driveabilty, or any of the other typical shortcomings that most suspension companies can get away with on vehicles like Wranglers and pickups."
The Electronic Stability Program presented the biggest engineering challenge. "It really is an incredible system in terms of safety, but when you modify a vehicle with a lift kit, the ESP tends to go nuts," Dave Harriton says. "So the primary delay in getting the kit to market has been developing the necessary hardware and software to compensate for the lift."
AEV offers the lift installed on its new "trail-ready" Grand Cherokee and Commander conversions.