An "Old" JK Wrangler Unlimited Is New Again
Saying a JK is "old" sounds strange, as they've only been available since mid 2006. But that's two years, and two years in the Jeep world can be a long time if a vehicle is ridden hard and put away wet. We got our hands on a 2007 Jeep JK Wrangler Unlimited Rubicon that had been one of the very first off the assembly line in 2006. This JK had seen 31,000 miles of tough use and little maintenance. For example, when we pulled the crankcase drain plug, black liquid came out that looked more like tar than oil. There was sludge in the oil pan. It was time for a project!
While this JK was a Rubicon, we decided that we wanted to run 40-inch tires on it, so the stock axles probably wouldn't hold up. We contacted Dynatrac and ordered a pair of Pro Rock 60s with 5.38 gears and Eaton Detroit Lockers. The Pro Rocks will hold up to anything we plan on doing with the JK. While the front and rearends were being built, we made plans for the rest of the Jeep.
The hard top had a hole in it, so it needed to be repaired. The paint was OK, but needed some touching up. The sludge-filled 3.8L V-6 was problematic. When was the last time the oil had been changed? Had the JK been thrashed and not maintained at all? We decided to change everything.
Dan McKeag and the staff at Burnsville Off-Road in Burnsville, Minnesota, had built two Hemi projects for us in the past that worked perfectly with no issues. Their JK V-8 conversions look as if they came from the factory. Burnsville started as a body shop, so Dan's staff also do paint and bodywork. Obviously, they would be the perfect shop to build our JK. After talking with Dan, it was agreed that Burnsville would perform our JK makeover.
We had built a project YJ in Off-Road Magazine that was painted Ford Grabber Blue. We really liked the way that Jeep looked, so we told Dan and crew to paint the JK Grabber Blue, too. They went to work stripping the JK down, as the inner door panels and many other pieces needed to be painted. Before the JK had the black armor and top reinstalled, the staff at Burnsville was calling our JK "Smurf." After everything was bolted on, they grudgingly admitted that it looked great. Burnsville also repaired the top to factory specs.
By the time the Jeep was out of the paint shop, the Dynatrac Pro Rock 60s had arrived. Dan does some work with Mopar Performance, so he suggested we try the new Mopar/Rubicon JK suspension. While this kit is basically a Rubicon Express long-arm suspension system, some things are changed, such as track bar mounting and shock valving. We gave him the go-ahead and the Pro Rock 60s and Mopar/Rubicon suspension were installed under the JK. Both the Pro Rock 60s and the Mopar suspension were built for JK Wranglers and were installed with no issues.
At the time this JK was being built, Burnsville had a number of brand new takeout 3.8L V-6 mills sitting in storage. We decided to install one of these into our old/new JK and replace the worn-out 3.8L. This was fine, until Dan reported that he had driven the Unlimited with 40-inch (39.5) Iroks and said that it worked great in low range, but highway performance was sad, even with the 5.38 gears in the Dynatrac 60s. It looked like a Hemi was in our JK's future.
We decided that a 5.7L Hemi with 545RLE five-speed automatic would wake things up. A 6.1L Hemi intake was installed on the 5.7L, giving us about 25 more horsepower than the stock 5.7L produces. The 545RLE mates up to the Rubicon RockTrac transfer case, so no adapter was required. Burnsville uses its own aluminum radiator and an AEV harness, so everything looks and works as Burnsville swaps always do - like OE.