Phil Howell
Editor-in-Chief
Photographers:
Joe Betar
Many H1 Hummer owners lived by the creed, “He who dies with the most parts bolted on their Hummer wins.” Now that the H1 is history, you’re thinking many of these owners, and others with the same personality profile, have transferred their interest to the JK Wrangler Unlimited. There are JKs out there that don’t have room to bolt one additional part anywhere. Those Wranglers look ridiculous and don’t work in the backcountry. An intervention is called for to keep those owners from overloading their Jeeps and turning them into sources of derision.
However, JK Wranglers aren’t to blame for this phenomenon. Since 2006, when the JK was introduced as an ’07 model, it’s been proving itself in the dirt and on the pavement as a competent, comfortable, and worthy successor to Jeep’s civilian utility vehicle line that started with the CJ-2A. Joe Betar, owner of Classic Motors in Richfield, Utah, knew this and contacted John Williams of Impulse Off Road to build a relatively simple and clean ’14 JK Wrangler Unlimited Rubicon daily driver and wheeler.
Great JK builds can be relatively simple, but glaring JK defects need to be repaired. John knew the very first problem that had to be addressed when building a JK is the weak Rubicon Dana 44 front axle. The stock axletubes are prone to bending and cracking, the ball joints fail, and the inner knuckles bend. Many companies offer beef-up kits to remedy these issues, but John made the simple choice and installed a Dynatrac ProRock 44 Unlimited up front. The rear Rubicon Dana 44 was retained, with a Dynatrac cover protecting the OE Tru-Lok electronic locker and Yukon 4.88 gears.
Synergy Manufacturing has been in the JK suspension game from the beginning and continues to bring innovative products to the table. Its track-bar bracket and sector shaft brace kit addresses the weaknesses in the stock JK steering system. If a ram assist isn’t installed on a JK, this kit should be. This kit, coupled with Synergy’s Stage 3 suspension, ticks most of the boxes needed to turn the Wrangler into a competent off-road Jeep. We especially like the fact Synergy arms can be easily adjusted while on the Jeep.
The Expedition One CORE Series front bumper holds a new Warn PowerPlant 9.5 integrated winch and air compressor. The rear Expedition One bumper is one of the smaller JK offerings that doesn’t require frame trimming. On a JK, smaller is better. The OE Rubicon rocker guards were retained. A TeraFlex tire carrier kit was installed to carry the spare and beef up the rear door and hinges, and 37x12.50R17LT Goodyear Wrangler MT/R tires were mounted on a set of Weld Racing Rekon forged alloy beadlock wheels that are tough and great looking.
The Pure and Simple JK is just that. Impulse Off Road added what’s needed to improve the JK Wrangler and nothing else. Joe received the Jeep back ready to hit either the trail or the tarmac.
Jeep’s 3.6L V-6 and W5A580 five-speed automatic transmission do a credible job motivating the JK. This engine was left stock.
The ProRock 44 Unlimited is designed specifically for lifted JKs. The Unlimited has added steering caster for a 21⁄2-6-inch lift. The shock mounts are moved out one inch to provide better shock/frame clearance during full articulation. The housing is a direct bolt-in and allows the factory brakes, knuckles, axles, gears, and electric locker to be retained.
PhotosView SlideshowThe 4.88 Yukon ring-and-pinion sets came with everything needed for a successful installation. You can see the great pattern John was able to achieve.
John chose Ultimate CV Axles with 300M inner ’shafts from RCV Performance. Tests proved the Ultimate CV Axles are twice as strong as OE Jeep JK ’shafts, and they’re just as strong at extreme angles where U-joints are weakest. The upgraded 300M (used in aircraft landing gear) inner ’shafts provide an even greater tolerance to stress. Rear 300M Dana 44 ‘shafts are also available from RCV Performance.
PhotosView SlideshowSynergy Manufacturing’s Stage 3 JK short-arm suspension comes with everything needed for an easy, bolt-on installation, including bumpstop extensions, brackets, and DOT stainless brake lines. John chose to use Teraflex 9550 monotube shocks. The 9550’s are valved well for JK applications. Also shown is the Synergy track bar and sector shaft brace kit.
All Synergy adjustable control arms, both short and long, can be lengthened or shortened while still on the vehicle. This makes dialing in the suspension, rotating the pinion, and dialing out driveline vibrations easy.
The Dynatrac ProRock 44 Ultimate front axle assembly loaded with Yukon 4.88 gears, OE Tru-Lok electronic locker, and RCV Performance Ultimate CV Axles with 300M inner ’shafts was a simple bolt-on installation. The stock Rubicon SmartBar electronic sway bar was retained, so the Synergy Stage 3 sway-bar links were used. Synergy’s track bars are adjustable on the vehicle, exactly like its control arms.
The Jeep 241OR Rock-Trac T-case has had some issues with the cases cracking. John Williams had one of his fail, so he designed a fix. The Impulse Off Road NVG241 case reinforcement bracket makes broken 241 cases just a remembrance. John tested the bracket on his King of the Hammers JK. While other parts failed, his 241 remained unbroken and pristine. He now installs these on all of Impulse Off Road’s JK builds.
A Dynatrac cover protects the Yukon 4.88 gears and OE Tru-Lok electronic locker in the rear Rubicon Dana 44 housing. Synergy’s track-bar bracket raises the lower track-bar mounting point for correct geometry. The Jeep articulates well for an all-around JK.
Expedition One’s CORE Series front bumper is about as compact as can be when leaving the JK framerails untrimmed. It looks clean and is a great mounting place for the new Warn PowerPlant 9.5. The improved winch features a powerful compressor with an output of 12 cfm at 0 psi.
Up to a 40-inch tire can be carried on the Teraflex tire carrier and hinge reinforcement kit. The spare is completely rattle-free. The Trail Series bumper from Expedition One is good looking and can be ordered with or without D-ring tangs. If the receiver is there, why use D-rings?
The 37x12.50R17LT Goodyear Wrangler MT/R with Kevlar tires are mounted on Weld Racing B57B Rekon beadlock wheels. The Rekon beadlock is a tough forged (not cast) alloy wheel. The beadlock ring is beefy, and the nano-ceramic Advanced Tactical Coating is strong. The wheels carry a 2,600-pound load rating, even with a 40-inch tire! They’re designed, tested, and manufactured in Kansas City, Kansas.
PhotosView SlideshowCheck out the difference between the Weld beadlock Allen head bolt and a brand X beadlock bolt. With tire bead bundles getting thicker, it’s difficult to mount them correctly to many beadlock designs. The Weld Rekon has a generous step milled into the wheel and ring to allow for this. Tires with the thickest bead bundles like our Goodyears can be mounted, yet there’s still adequate clamping pressure for tires with thinner beads.
The Pure and Simple JK leaves Impulse Off Road for Classic Motors in Richfield, Utah. It sits perfectly, and the 37-inch tires don’t rub, even with 3-inch coils. John Williams knows where to trim if trimming is needed.
