Jerrod Jones
Former Editor, Off Road
When our newest ’14 Wrangler Unlimited Rubicon project entered the Four Wheeler family wearing Anvil Grey paint, we weren’t about to name it “Pinky.” Anvils are big, heavy, and basically unbreakable. They’re meant to take a beating—literally. They’re the type of thing that gets passed down from father to son after years of being pounded against and never really destroyed. They might acquire some nicks and dings over time,but nothing that will keep them from doing their job. The plan behind the Anvil is to outfit it with the most durable, proven parts we can, while keeping all the luxury that comes in a new Rubicon Wrangler and only improving the comfort and ability of this do-all family go-getter.
Before
All anvils need a big, steady foot to make sure they stay in place, and subsequently we decided to start at the feet of our Anvil, outfitting our brand-new Rubicon Wrangler with 35-inch Toyo Open Country MTs on AEV Pintler wheels. To make sure the new wheel and tire package fit without any cutting, we needed to lift it but only a couple inches. And if we’re going to be replacing stock suspension parts, then we’re going to get the most bombproof replacements we can. With solid-stock control arms and heavy-duty everything else, the Rock Krawler 2.5 X-Factor Stage 1 mid-arm suspension system was the perfect choice. It not only keeps our JK low, but it also improves the ride and adds stronger parts. Since this is a high-end build, we enlisted the Jeep specialists at Jeeps R Us in Laguna Beach, California, to handle the work. With every kind of Jeep passing through its doors, it was an easy choice as to which shop we entrusted to assemble our bolt-together Jeep properly.
With a natural first step of lift and tires installed at Jeeps R Us, our Jeep build is well underway. Check back for Part 2 of our project where the upgrades start coming fast and feverously.
Brand new tires, wheels, stock suspension—all gone. Jeeps R Us put our JK on a lift and stripped it down. First, all four wheels and tires were pulled, and then each corner was addressed separately, not completely removing everything at once so we only had to support and work on one corner at a time. Since this kit uses factory control arm mounting points and has new coil springs that aren’t that much taller than stock, installing the new parts is just that much easier.
The front part of the Rock Krawler 2.5 X-Factor Stage 1 Wrangler suspension includes four factory-replacement heavy-duty control arms, track bar, long-travel multi-rate coil springs (triple-rate, actually), sway bar links (the ones pictured are actually for the rear), brake lines, bumpstop extensions, and 2.0 RRD shocks. Going with a Stage 2 kit gets you remote-reservoir RRD shocks, but for our build the 2.0 RRD shocks offer all the performance we need. They’re really nice units.
Rock Krawler’s 2.5 X-Factor Stage 1 rear section also includes four control arms, a heavy-duty track bar, multi-rate coil springs, sway bar links (the ones pictured are actually for the front), bumpstop extensions, and 2.0 RRD shocks. To keep all angles and geometry perfect, the rear also comes with angled spring shims and a track bar relocation bracket.
Rock Krawler’s control arm ends are either a Krawler joint with high-misalignment balls, or a poly-blend bushing. The rear control arms are designed to move the rear axle rearward 1 inch, plus all eight control arms are adjustable in length to set the appropriate caster, depending on how much lift you have. If you start with a 21⁄2-inch lift spring and go up to 41⁄2 inches of lift, you’ll be able to adjust the arms accordingly.
Bumpstop extensions are included to account for the 2 1⁄2 inches of lift on our JK Wrangler project. You’ll have to drill out the hole in the spring pad in order to slip in the supplied bumpstop extension bolt.
Long-travel, multi-rate coil springs are included for all four corners. At 21⁄2 inches taller than stock, there is a minimal change in center of gravity, and the variable spring rate is matched to the included nitrogen-charged shocks. It’s a very controlled, nice-riding system that we’re highly impressed with.
The 1 1⁄4-inch solid-steel upper control arms bolt directly in place of the factory units. The instructions dictate adjusting the arms to 195⁄8 inches between mounting eyes for the 21⁄2-inch suspension.
The lower front control arms are made from 1.625-inch solid steel, and also bolt directly in place of the factory control arms. They are angled for high clearance in uneven terrain. They need to be adjusted to 231⁄8 inches for the 21⁄2-inch suspension.
The track bar uses a large Heim joint at the axle side and a poly blend bushing Flex joint at the other end. It is completely adjustable for varying lift heights, but for a 21⁄2-inch kit, it’ll need to be 329⁄16 inches.
Adjustable sway bar links are supplied for the front and rear of the vehicle. If you have a Rubicon Wrangler with a disconnecting sway bar, then you don’t need the disconnect links.
Nitrogen-charged 2.0 RRD shocks are supplied with the 2.5 X-Factor system. They’re specified for the JK Wrangler with the correct ends to mount in the factory locations. No hokey adapters that can come loose and fail in the field. Overall, we were very pleased with the thoughtful engineering put into the Rock Krawler system.
A completed frontend kit from Rock Krawler should look like this. There is more suspension dropout thanks to the slightly longer shocks. Make sure to adjust the sway bar links so that they don’t fold the wrong way upon compression after full suspension extension.
When you lift the rear of a JK, the spring pad becomes slightly angled as the pinion is rotated up for driveshaft angles. Rock Krawler supplies lower shims to keep the rear coil springs sitting correctly on their buckets and prevent the springs from bowing.
The rear bumpstop extensions are elevated and pushed forward to properly meet the bumpstops when compressing the newly lifted suspension.
A track bar relocation bracket realigns the track bar to keep the correct geometry. Even at 21⁄2 inches of lift, Rock Krawler knows that the adjustment needs to be made. An included sleeve is slipped in place of the original track bar so the factory axle bracket doesn’t crush when you tighten down the bolt to hold the relocation bracket.
The rear coil springs are long-travel, multi-rate units just like the front. The coil wind is smaller than the factory coils through the middle but the same on the ends so it fits just like a stock coil spring would. The tighter wind in the middle allows coil-to-track bar clearance even with the rear axle an inch further back.
The rear upper control arms for a 21⁄2-inch kit on a four-door JK need to be adjusted to 187⁄16 inches. The lower arms need to be adjusted to 211⁄16 inches. These measurements are slightly different for a two-door JK.
With most of the rear kit finished, we buttoned up the last few parts, including the rear Rock Krawler 2.0 RRD shocks and the completely adjustable track bar, made from 11⁄2-inch solid steel.
With a top-tier build such as this, we weren’t about to skimp on tires and wheels. The 17x8.5 AEV Pintler wheels are specifically designed the JK Wrangler and fit like a glove. We brought our wheels and 35x12.50R17 Toyo Open Country MT tires to our local Discount Tire to be mounted and balanced. We’ll cover the wheels and tires in more detail in the next installment. Larry Garcia at Jeeps R Us hefted all four into place and our ride was done
Rock Krawler includes new longer stainless steel braided brake lines with the X Factor suspension, so we dutifully installed them. Here’s the completed rearend of our Project Anvil JK Wrangler.
After
