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Rock Krawler Suspension 3.5 Off Road Pro TJ Suspension Review

Posted in How To: Suspension Brakes on March 1, 2017 Comment (0)
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The biggest nemesis of the 1997-2006 Jeep Wrangler TJ in the dirt is its 93.4-inch wheelbase. While the relatively small SUV is great for tight trails and cruising around the city, it doesn't lend much in the way of stability when it comes to steep hillclimbs. Couple this modest wheelbase with a short-arm suspension lift and you have the recipe for a very tippy TJ. Thankfully, there are plenty of ways to increase stability on this Wrangler platform.

One of the best is by upgrading to a long-arm suspension. Ditching the stock-length control arms with a longer set not only provides increased control and stability off-road but also tremendously improves the ride quality and the overall handling dynamic on the highway. While upgrading to a long-arm suspension is a great start, stretching the wheelbase is key to getting increased stability with the TJ platform. Recently we stopped by Low Range 4x4 in Wilmington, North Carolina, where the crew was busy at work on a 1999 Jeep Wrangler. This particular Jeep was being outfitted a Rock Krawler Suspension 3.5 Off Road Pro Stage 1 stretch kit. What makes this kit unique is not only that it is a long-arm upgrade, but it stretches the wheelbase by 5 inches. Rock Krawler actually offers a few variations of the 3 1/2-inch system to accommodate budgets and needs.

This particular Jeep owner sought the Off Road Pro version of the kit because the 7075-T6 aluminum control arms would help keep the weight down while providing plenty of durability for the Southeast trails he likes to wheel. Although body modifications are also part of the suspension stretch process, in this article we focus on the suspension.

The heart of the system is the 1/4-inch-thick steel three-piece crossmember. This setup bolts to the TJ’s framerails, and the heavy-duty centersection offers an additional inch of ground clearance over stock.
One of the unique aspects of the Off Road Pro version is the 7075-T6 aluminum control arms. From Ultra4 cars to everyday trail wheelers, we are seeing a trend toward aluminums. This is largely due to the strength and weight savings it offers over a more traditional DOM control arm. Each link is fit with Krawler Joints, which makes for easy suspension adjustment and plenty of degree rotation for the suspension to articulate freely.
To get the chassis ready for the new suspension, all of the stock lower control-arm mounts will need to be removed. Since this kit uses coil springs out back, you will also need to remove the stock coil perch and track bar mount at the frame.
Set back 5 inches from the stock coil perch, Rock Krawler provides a weld-on coil perch to secure the springs out back. This setup comes with an integrated bumpstop mount, which is also adjustable.
To secure the new upper control arms, Rock Krawler provides an axle truss. This truss is axle-specific and, in this case, was ordered for a Dana 44 rear axle. To burn it in place, you will need to remove the axle’s upper control arm and track bar mounts.
The new rear suspension is set up as a triangulated four-link and allows you to retain your stock rear sway bar if you so choose. You will need to plan on having your driveline lengthened along with a new exhaust system for this kit.
This TJ owner knew he’d likely move to coilovers in the future, so he had Low Range 4x4 modify a set of coilover towers to accommodate the Rock Krawler 2.0 RRD Spec’d Prodigy Shocks. These sport-tuned absorbers work great with the 3 1/2-inch multirate coil springs. To ensure that the shocks wouldn’t have to carry the load of the axle on droop, a set of limit straps was added.
Up front, Rock Krawler uses a heavy-duty control arm mount that welds to the axle on the passenger side. This TJ was equipped with a TNT truss, which was modified to work with the weld-on bracket.
Unlike out back, the front suspension uses a three-link suspension design. This setup uses a track bar to center the axle and works great to allow smooth, bind-free movement of the front axle as it cycles and articulates.
Since the amount of lift is relatively low, Rock Krawler provides an adjustable track bar that attaches to the stock track bar locations. This TJ is fit with a Dana 44 front axle from a Jeep Wagoneer, so it’s not quite identical to stock. Also included with the suspension are new steel braded brake lines and sway bar disconnects.
Jeeps are often a hodgepodge of aftermarket parts, and this one is no exception. To accommodate the 5 inches of new wheelbase, a new fuel tank, rocker guards, and rear corners from GenRight were installed. Coupled with the aftermarket front fenders, there was ample room from the 35-inch-tall BFG KM2 tires to travel.

Dirt Pro

We got a chance to tag along for the Jeep’s first time in the dirt post-install. While the owner reports that the on-road handling is light-years better than before, we were able to witness the new setup in action off-road. We were extremely impressed with how smoothly the Jeep took obstacles and uneven terrain, which we attribute partly to a well-paired spring and shock combo and the nearly flat control arms. The only downside of the longer control arms is typically you will hit them a bit more off-road. Now working with a more hill-friendly 99-inch wheelbase, the Jeep is more planted and stable on the trail. We are told 37s with beadlocks are the next upgrade to the TJ, which should increase some of the trail performance even more.

PhotosView Slideshow

Sources

Low Range 4x4
Wilimington, NC 28412
910-392-3204
www.lowrange4x4.com
Rock Krawler
518-270-9822
www.rockkrawler.com

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