Doctor’s Orders: How a Impulse Offroad Got This Jeep JK Sick
A doctor friend of ours likes to get into the dirt whenever he can.
Whether it’s using motorcycles, ATVs, side-by-sides, or 4WD vehicles, he’s beating them up in the backcountry on his days away from the hospital. It gets cold in the Utah mountains where he lives, so our doctor ordered a new 2014 Jeep Wrangler S so he’d have an enclosed vehicle to explore the backcountry when the weather turned bad. As he has considerable experience with 4WD vehicles and Jeeps in particular, the doctor knew a stock Wrangler wouldn’t do, so he ordered parts and contacted JK Wrangler expert John Williams at Impulse OffRoad to build the Wrangler into a backcountry beast.
Throughout this feature, you’ve noticed we talk about both 37-inch BFGoodrich All-Terrain T/A KO2 and 39-inch Krawler T/A KX tires. The doctor uses both. Here are the 37×12.50R17/D KO2s mounted on OMF Performance beadlock Fuel wheels. OMF Rock Domes protect beadlock bolt heads in the rocks. The KO2 All-Terrain tires work well on the pavement and in the dirt, on the rocks, or in the sand. Poison Spyder Customs’ Rocker Knockers (rocker panel protection) ride high for outstanding ground clearance.
The parts ordered included Dynatrac ProRock 60 front and rearends with 4.56 gears and Eaton ELockers. As Jeep experts know, the JK Wrangler Dana 30 and 44 front ends are woefully inadequate – even for light duty backcountry exploring. The housing and ball joints fail and inner knuckles bend, not what’s wanted when miles from civilization.
The Poison Spyder Customs Brawler Mid front bumper is a great place to mount the Warn ZEON Platinum 10-S wireless winch with required Poison Spyder spacers and Warn Epic forged winch hook. Baja Designs Squadron Pro LED lights illuminate the darkest trails, as do the Quadratec LED headlights and foglights. Daystar fairlead rollers allow a roller fairlead to be used with synthetic line and are a great place to clamp a license plate in states that require a front plate. Daystar Hood Wranglers replace the wimpy OE hood tie downs and stop hood fluttering at freeway speeds.
Under the hood, the Jeep’s 3.6-liter V6 was left alone. An Odyssey sealed battery was installed, and the brake pump was moved from the frame to the front of the brake booster to provide front bumper clearance.
While considering his suspension configuration, the doctor decided to go with a short arm system, as OE JK arms aren’t all that short to start with and he wanted the ground clearance mid-frame that’s lost when long lower control arm bracketry is used. To further aid geometry, a pair of AEVs excellent geometry correction brackets were ordered. Synergy Manufacturing control arms were chosen as they can be adjusted while on the Jeep, a real time saver when dialing in the suspension. Teraflex 3-inch JK coils have the best rate of any available and Teraflex SpeedBumps allow fast driving in the outback. Spicer adjustable reservoir shocks have 16 compression adjustment settings and provide a comfortable ride whether the Jeep is traveling long backcountry distances or rock crawling. Finally, the OE swaybar was replaced by a Currie AntiRock swaybar that works well on and off road.
39×13.50R17/C BFGoodrich Krawler T/A KX tires are mounted on OMF Performance-beadlocked Black Rock Yuma wheels. The Krawlers provide great ground clearance and traction in hard core terrain.
A Teraflex JK HD Hinged Carrier and Adjustable Spare Tire Mounting Kit reinforce the tailgate and hinges to carry a spare tire rattle-free. The mounting plate is adjustable for any wheel backspace and the tire can be mounted high or low on the plate. The doctor added a Teraflex can carrier and Rotopax gas can to increase exploring range. The can carrier provides a place to mount an antenna.
Poison Spyder Customs armored the Jeep with a Brawler Mid front bumper, a high clearance BFH rear bumper, and 2-door Rocker Knocker rocker guards. A Warn ZEON 10-S Platinum wireless winch was installed on the Brawler bumper, as were Baja Designs Squadron LED lights.
Check out the photos and captions for more details on how Impulse Offroad worked their magic and built the Jeep, then made sure everything was dialed-in. With the installation of the MCE carbon fiber-look flat flares, the Jeep can run not only the 37-inch BF Goodrich All-Terrain T/A KO2 all-terrain tires originally planned, but a set of 39-inch BF Goodrich Krawler T/A KX tires when gnarly wheeling is anticipated. The Wrangler exceeded everyone’s expectations and works well everywhere. On or off road, mild exploring or wild wheeling, this Jeep is everything the doctor ordered.
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- Teraflex 3-inch single rate JK Wrangler coils, SpeedBumps, Spicer adjustable reservoir shocks, and a Currie AntiRock swaybar are an unbeatable combination for on- and off-road performance.
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- 39×13.50R17/C BFGoodrich Krawler T/A KX tires are mounted on OMF Performance-beadlocked Black Rock Yuma wheels. The Krawlers provide great ground clearance and traction in hard core terrain.
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- OE Jeep transfer cases have been known to crack open. John Williams, owner of Impulse OffRoad, designed and offers this Jeep transfer case reinforcement plate that solves that issue. John installed one on the 241J transfer case. Tom Wood’s Custom Driveshafts built the front and rear 1350 CV driveshafts.
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- The rear Dynatrac ProRock 60 has 4.56 gears and an Eaton ELocker installed. Check out that ground clearance! Seriously, when running 39-inch Krawler T/A KXs, the Jeep has 13-inches of ground clearance at the lowest point of the ProRock 60s. A Teraflex Monster Track Bar is adjustable and ensures there will be no axle centering issues.
Impulse Offroad Jeep UPGRADES
Platform:
2014 Jeep JK Wrangler Sport S
Engine:
- Jeep 3.6 liter VVT V6
- Odyssey sealed battery
- MPFI induction
- Jeep WA580 5-speed automatic transmission
- Jeep 241J/2.72:1 transfer case
Suspension:
- Teraflex 3-inch coils
- Teraflex SpeedBumps
- Spicer shocks; Currie AntiRock Synergy control arms
- Dynatrac ProRock 60 (front end and rear end)
- Eaton ELocker (front and rear differential)
- Teraflex 3-inch coils
- BF Goodrich 37-inch
- All-Terrain T/A KO2 and 39-inch
- Krawler T/A KX
- OMF Performance-beadlocked Fuel
- OMF beadlock Yuma/4.75 inch
Accessories:
- Cobra 75WX all-in-one CB radio
- Warn ZEON Platinum 10-S wireless winch
- Baja Designs Squadron Pro LED lights
- Quadratec LED headlights and foglights
- Teraflex can carrier
- Rotopax gas can
- Teraflex JK HD Hinged Carrier and Adjustable Spare Tire Mounting Kit
- MCE carbon fiber-look flat flares
- Poison Spyder’s BFH rear bumper
Editor’s Note: A version of this article first appeared in the Spring 2016 print issue of Tread Magazine.
