13. Here you can see how the new rear track-bar relocation bracket mounts to the factory track-bar bracket. We like the way JKS designed this part because it includes a zinc-coated crushproof sleeve inside the factory bracketry as well as a second bolt to help distribute forces further down on the OE bracket. Also notice the way the bracket relocates the track bar up and closer to the centerline of the axlehousing; this assists in correctly aligning the track bar once the axle has been rotated to accommodate the new CV driveshaft. This part transmits a ton of lateral force to keep the rear axle located under the Jeep. JKS knows this and designed a system that won't let you down. | 
14. This shot shows the new extended stainless steel braided brake lines supplied with the J-Spec system. These are about as nice as brake lines get. In addition to being made from a much stronger braided material, they feature a protective red sleeve designed to provide "witness marks" in case something accidentally comes in contact with the lines. This helps you troubleshoot clearance issues as well as preserve the good looks of the stainless steel. With these lines, you can expect improved braking performance and pedal response. | 
15. We chose a smooth-riding set of Goodyear MT/R tires for this project. Our good friend Tom Lonardo at Goodyear's Los Gatos, California, store always takes care of his customers, and in our case there was no exception. Tom had our new 32-inch tires mounted and balanced in a little over two hours. The OE Jeep Rubicon wheels were provided by the Jeep's owner. Here you can see Overkill's apprentice fabricator Corey Allen muscling one of the new tires in place. |
Testing
Our initial testdrive revealed the J-Spec front springs were a little firm on our four-banger Jeep. We anticipated this because JKS designed the coils for the heavier six-cylinder engine. To compensate for the weight difference (and to improve the Jeep's trail functions), we installed an ARB front winch bumper and a Ramsey 8,000-pound electric winch. These additions increased the weight over the front springs, proving to be the perfect solution. Once installed, the Jeep felt perfectly balanced and the testing continued.
Wrapping up our six-month evaluation over a variety of different terrains, we had nothing but good things to say about the J-Spec Suspension system and the U-Turn steering upgrade. The Jeep improved big-time on the road and in the dirt, in both ride quality and articulation. This assured us that the J-Spec system was the real deal. It became obvious just how much all those little extra features contribute to the system's overall performance. This is one of the those times when the expression "the whole is greater than the sum of its parts" certainly applies. Everything from washboard to boulders confirmed our suspicions that JKS really did their homework before releasing this new system. After several thousand highway miles, we didn't hear any of the typical squeaks and rattles found with other less-expensive kits we've tested. The ride seemed to get even better as the springs broke in. The slightly larger tires had only a minimal effect on power and fuel consumption. The owner does plan to swap in a stroked 4.0L soon. Once he does, we suspect a set of 33s will follow suit. Lucky for him, the 4 additional inches of clearance will accommodate these without issue. For now, however, this Jeep is ready to rock.