I like two-door JK Wranglers. I like the way they look and the way they work on the trail. I also like dual sport 4x4s that work as daily drivers and trail vehicles. Therefore, when I found a good deal on this 2008 Jeep Wrangler JK Rubicon, I snapped it up. The Trailrunner, a JK that can go fast like a prerunner and still tackle tough trails, is about to be born.
The Wrangler came with pretty much everything on it, including navigation. This will be good for entertainment on long backcountry forays. It has the 3.8L V-6 with 42RLE automatic tranny, NVG241OR Rock Trac transfer case, and the Rubicon 44 front and rear ends with E-lockers and electronic swaybar disconnect. I plan to build this in stages, with Stage I including bolt-on parts and minor fabrication.
I took the JK to Mount Logan Off-Road so they could install their Bombproof Axle Kit that addresses the weak inner knuckles and tubes of the JK 44. An RCV Performance Ultimate Dana 44 JK Rubicon Front CV Axle kit replaced the OE axles. While this was being done, JKS control arms and track bars were installed, as were KORE coils and KORE/Fox reservoir shocks. An R-SE swingaway tire carrier bumper and a Shrockworks stubby front bumper with a Warn PowerPlant HP winch guard the front and rear of the Jeep. A set of 37x12.50R17LT Goodyear Wrangler MTR with Kevlar tires were mounted on 17x8 Black Rock Viper wheels.
The JK then went to Kevin Hawkins for the installation of a PSC JK Extreme Duty Cylinder-Assist kit. Kevin is a ram-assist expert and enjoys installing the systems on everything from Jeeps to buggies. As a result, the PSC system works great and the Trailrunner's steering is flawless. Currie Enterprises' beefy new CurrectLync tie rod and drag link were also installed. Being a believer that lighter is better, a pair of Teraflex aluminum rocker guards were procured that are light, yet strong.
The Trailrunner was now in my garage. It looked good, but was generating Diagnostic Trouble Codes (DTCs). P0055 and P00F9 kept popping up. I couldn't find what P00F9 was, but P0055 was supposed to be HO²S Heater Resistance (Bank 1 Sensor 3) according to an Internet search. This was a downstream O² sensor problem, so I changed both downstream O² sensors, cleared the DTCs, and started the Jeep. The Check Engine light immediately illuminated. P0055 and P00F9 were there again. I could also smell gas fumes every time the JK was started. I always use a Kilby vapor-recovery canister relocating kit when building a JK and this Wrangler was no exception. The Kilby kit was installed the same as all the other kits had been, but when I pulled on the rubber hoses that went over the plastic hard lines, they moved easily. Hose clamps cured the gas fumes. Guess what? No more DTCs, either. I bet P00F9 means a fuel system leak. P0055 may have something to do with that, too, as neither code has returned. Maybe the internet key to DTCs has a GM code description and Chrysler uses the codes to mean something else? Who knows?
The Shrockworks stubby front...
The Shrockworks stubby front bumper is one of the few bumpers that put the fairlead hole where it needs to be, in front of the winch drum, rather than in the center for looks.
Everything JKS manufactures...
Everything JKS manufactures is high quality. JKS Control Arms utilize greaseable brass bearings for smooth operation and longevity. Fine pitch adjustment threads make it easy to "tune" the JK with over 3 inches of range. The Trailrunner now has a 97.5-inch wheelbase. New OE rubber bushings are used to isolate road noise and vibrations without over-stressing the mounting brackets. JKS track bars are strong and adjustable, although you need a minimum of 3 inches of lift for them to work (they're longer than stock at their fully collapsed length). They utilize OE bushings for reliability and quiet operation. Have you driven a modified JK that had a completely silent suspension? You can if the JK is equipped with JKS control arms and track bars. The bracket shown here is a strong JKS rear trackbar bracket, which we didn't use as we needed to raise the rear trackbar.
Kent Kroeker, owner of KORE,...
Kent Kroeker, owner of KORE, pays attention to the slightest details when designing a suspension system. He told me he didn't have coils or shocks for the two-door Wrangler and that his four-door suspension wouldn't work for us. I talked him into sending KORE's Technical Series suspension that includes KORE/Fox 2.0 reservoir shocks and KORE's excellent coils anyway. Kent was right. The coils and shock valving weren't perfect for our two-door. The coils were too long, although their rate was good. Even though the Trailrunner was too tall, I was still able to get the JK up to 80 mph in the dirt using this excellent suspension. I hope KORE offers a two-door JK Wrangler suspension soon. The Technical series also comes with bumpstops, DOT braided stainless brake lines, rear swaybar links, and an adjustable front track bar. The trick aluminum front swaybar links you see here are no longer available.
The 5.38 Sierra gears from...
The 5.38 Sierra gears from West Coast Differentials set up easily in the Rubicon 44 front and rear ends.
The Sierra gears and OE E-lockers...
The Sierra gears and OE E-lockers are protected by Dynatrac diff covers front and rear. The JK plastic air dam and sheetmetal crossmember were removed so an Expedition One Rubi Skid could be installed. The Rubi Skid protects the Rubicon swaybar disconnect mechanism and tucks up under the bumper for more ground clearance. Poly Performance's front track bar bracket raises the trackbar where it needs to be when the drag link is flipped to the top of the knuckle.
Currie Enterprises' new CurrectLync...
Currie Enterprises' new CurrectLync JK drag link and track bar have massive ends that can be flipped to the top or bottom and are built using 1.5-inch solid stock. The PSC JK Extreme Duty Cylinder-Assist kit includes everything needed for a successful ram-assist installation. Trailrunner's steering is easy and smooth everywhere. The trademark orange boots come on RCV Performance's patented Ultimate Dana 44 JK Rubicon Front Axle set. Remember when we used to do anything to get rid of Birfields? The RCV Performance CV axles are similar to Birfields in look only. They're smooth, even when turning at full lock, and strong. During testing, they stood up to abuse and, while the CV didn't break, the axle sheared at 7,604 lb-ft, similar in strength to a 35-spline Dana 60 axle. In comparison, the stock JK Rubicon 44 front axle failed at 3,872 lb-ft.