Rough Country’s Flexy New Long-Arm Jeep Grand Cherokee Suspension - Four Wheeler Magazine

Ken Brubaker Senior Editor, Four Wheeler

When Jeep trotted out the Grand Cherokee ZJ for the ’93 model year, it was aimed squarely at the Ford Explorer and Chevy S-10 Blazer. Compared to its XJ sibling it was larger and more luxurious, but underneath it retained proven simplicity with a pair of solid axles and a coil spring at each corner. The ZJ was a hit and Jeep sold a passel of ’em during the models six year run. Today, these vehicles are plentiful and inexpensive and a popular rig for buildups.

flextraordinary jeep Front Three Quarter Photo 32818676

Rough Country Suspension offers six suspension kits for the ’93-’98 Jeep Grand Cherokee ZJ. One of the newest is a member of Rough Country’s X-Series line and it’s a long-arm system that improves off-highway handling and articulation while raising the SUV four inches. The kit includes adjustable, high-clearance X-Flex upper and lower control arms with Clevite bushings, featuring rebuildable X-Flex joints with Adjustable Retainer Rings that allow you to preload bushings by compressing them prior to install. The kit also includes new coil springs, a front adjustable track bar with drop bracket, ¼-inch-thick steel crossmember and skidplate, sway bar disconnects, and Performance 2.2 Series shocks.

We recently traveled to Rough Country headquarters in Dyersburg, Tennessee, to watch a stock ZJ get the long-arm transformation and then we had a chance to hit the paved road and the trail in the newly modified rig. Following are the highlights of how Rough Country long-arm’s the ZJ and also an in-depth look at how the rigs performance improved from stock to modified.

Kit Specs
Rough Country says this kit was developed using a 31x10.50-15 tire with factory wheel, and that’s the recommended tire size. However, they say that this kit is capable of fitting a 32-inch tire or larger with some body/fender modifications. Aftermarket wheels will fit with 35⁄8-inch backspacing. Installation time is said to be 8-9 hours. At time of print, the MSRP on this kit is $1,499.95.

Bottom Line
In stock form, the ZJ was equipped with 245/75R16 (30.5-inch-diameter) Goodyear Wrangler RT/S tires. After the suspension install we mounted a set of 32x11.50-15 (31.3 inches actual diameter) Wild Country Radial MTX tires.

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When stock, the rig traveled 56 inches up our 20-degree RTI ramp to earn a score of 531. After the install, it traveled 61 inches with the sway bar connected to earn a score of 578. With the sway bar disconnected it traveled a whopping 83 inches up the ramp to earn an impressive score of 787. This translates to a 9 percent improvement with the sway bar connected and a 48 percent improvement with the sway bar disconnected.

Stock, the ZJ’s approach angle was measured at 45 degrees and the departure angle was 35 degrees. This improved to a 50-degree approach angle and a 40.5-degree departure angle after the install. This is an 11-percent and 16-percent improvement, respectively.

On the twisty Tennessee asphalt roads the lifted ZJ exhibited an outstanding ride and good handling. This is no doubt due in part to the fact that the Performance 2.2 Series shocks are valved specifically for this application. The minor overall tire diameter change meant there was no perceptible loss of power in the ZJ. It is worth noting that the kit requires removal of the rear sway bar because it would contact the longer control arms. We didn’t notice any handling weirdness on our test rig in its absence.

flextraordinary suspension Travel After Photo 34271932 After

We took the ZJ to the Bikini Bottoms Off Road Park and hit the trail. It was clear that the ZJ was in its element, and the suspension was at home cycling through its travel on the undulating trails. At one point, we purposely directed the Rough Country test driver into a rut-filled, off-camber area so we could see how the suspension reacted. In short, the design of the lift kept the belly and underbody components from snagging on obstacles and the ample flex of the long-arm X-Series suspension easily allowed the tires to stay in contact with terra firma.

We like that this suspension significantly improved suspension flex and it made the ZJ into an above average street/trail machine—and with only four inches of lift, the vehicle’s center of gravity remains low. We also like the design of the control arms, which contribute to good ground clearance. And we dig the large, flexy X-Flex joints and the fact they’re greasable and rebuildable. Oh, and the price of the kit is right, too.

PhotosView Slideshow Here you can see the contents of the 4-inch long-arm X-Series kit. The install begins at the front of the vehicle. After removing a number of components including the shocks, sway bar links, track bar, coil springs, and control arms, the lower control arm pockets are removed with a cut off wheel. These are removed to make room for the new control arms. Here you can see the driver-side framerail after the lower control arm pocket has been removed. After the factory transmission crossmember is removed a body saw is used to enlarge openings on each side of the frame. The cut simply follows the outside profile of the factory “dimple” in the frame. This is required to allow the installation of some of the flag nuts. The flag nuts are one reason Rough Country was able to design the kit so components could be installed without welding. The new crossmember mounts to the vehicle securely using factory and new mounting points. The crossmember not only supports the transmission but also serves as the rear mounting point for the new front control arms. Each side of the new crossmember is held in place by six fasteners. Here you can see one of the four new mounting points being drilled. Because the threads of some of the mounting bolts are located in the frame, flag nuts are used. Here you can see one of the flag nuts being installed on the passenger-side of the vehicle. The instructions are very clear as to which flag nuts are used in each position. Here you can see the passenger-side of the new crossmember with all of the mounting bolts installed but not tightened. The control arms go in next. The lowers are 2 inches in diameter and the uppers are 1¾ inches in diameter. X-Flex joints are used at the crossmember mounting positions and where the upper arms mount to the lower arms. Clevite rubber bushings are used elsewhere. A longer track bar bracket bolts in place of the factory track bar bracket using factory hardware. Longer, newly-designed sway bar links are included with the kit and they utilize new mounts at the sway bar as well as disconnect pins on the axle brackets. Holes need to be drilled in the center of each axle bumpstop pad for the 3-inch bumpstop extensions. Here you can see the driver-side coil spring and bumpstop extension being installed. All of the coil springs in this kit have an approximately 25 percent heavier rate. This was done to counter the added weight of larger tires and wheels and accessories. In this view of the finished frontend, most of the components are visible. You can also see the new 1¼-inch-diameter track bar, Performance 2.2 Series shocks, and optional steering stabilizer. At the rear of the ZJ a number of items are removed prior to installing the new parts. These include the track bar, shocks, sway bar assembly, coil springs, and control arms. Similar to the front, the lower factory control arm mounts at the frame (passenger-side shown) are removed using a cut off wheel to make room for the new components. A smaller aftermarket muffler is required with this kit (not included), so a cutting blade is used to remove the factory unit. Both of the upper factory control arm mounts need to be removed. To facilitate access and removal of the passenger-side upper control arm mount, the five rear nuts of the studs holding the exhaust heat shield are removed so it can be lowered. Here you can see the passenger-side upper control arm mount being removed. There's a new control arm bracket for each side of the vehicle and each bracket is mounted to the frame and requires drilling, crush sleeves, and utilization of flag nuts to install. The rear control arms are the same arms used in Rough Country's long-arm kit for the Jeep LJ. Like the front, the lower arms are 2 inched in diameter and the upper arms are 1 3/4 inched in diameter and utilize X-flex joints and Clevite bushings. This is how the drivers-side control arm bracket looked with the control arms installed before the fasteners were tightened. A new track bar bracket is included to compensate for the suspension lift and it mounts in the stock frame mount. The factory track bar is reused. Here you can see the completed rearend. Note the new coil springs, Performance 2.2 series Shocks, and bumpstop drop brackets. Not visible are the items used to relocate the brake lines.