The Jeep Wrangler JK has been around since 2006 as a 2007 model year and has significantly changed and expanded the Jeep world on several fronts. This Jeep, with its coil-sprung, solid-axle suspension, was an evolution of the Jeep Wrangler TJ, and while the TJ is known for having a smooth ride in its own right, the JK was a definite improvement. Still, like most Jeeps, enthusiasts have been modifying JKs since their inception, and the development of new parts to modify them has been constant since 2007. One of our favorite suspension companies, Skyjacker, has kept their suspension designs particularly fresh despite the passage of all that time . A few years ago, Skyjacker redesigned most of its coil-based suspension kits, upgrading the company’s coil springs from single-rate to double-rate (the benefits of using a double-spring are multiple, and we’ll touch on some of those benefits later). However, this change is not all that the company has done. Shock technology is changing rapidly in the aftermarket, and in line with that, Skyjacker has introduced several different optional shocks for use with their suspension systems, the latest being the new ADX 2.0 Adventure Series line. We recently had a chance to upgrade a friend’s 2013 two-door JK Sport with Skyjacker’s twin coil springs and a set of ADX 2.0 Adventure Series shocks. Here are the details.
What’s new with Skyjacker’s dual-rate coil springs?
The truth is, Skyjacker has had these twin coil springs for the Jeep Wrangler JK for a while, and we’ve known about them but we haven’t had a chance to use them yet. Still, we love the idea of dual-speed, long-travel coils on almost any 4×4 that uses coil springs. Here’s how it works: The more tightly wound coils at the top of the spring provide the softer first degree that gives the vehicle a smooth ride over small bumps (like when you’re on the freeway), and also allows the spring to stretch when the vehicle is flexed or articulated, which keeps the spring in the spiral buckets at each end longer; once these top coils are fully compressed during a bump or turn, the second gear enters the lower, wider coils, providing a firmer feel to absorb larger bumps and help keep the vehicle in control and stable in turns. This is a stylish design that delivers results on and off-road.
What’s new with Skyjacker’s ADX 2.0 Adventure Series Shocks?
Brand new to the market are Skyjacker’s ADX 2.0 Adventure Series dampers. Most of the details can be found here. These shocks feature a blow-extruded and CNC-machined T6061-T6 aluminum monotube body with a remote-mounted reservoir and a durable, clear anodized and polished aluminum finish. The aluminum body and reservoir help dissipate heat, which is the enemy of off-road impacts. The fully offset valve system is inspired by off-road racing shock absorbers. Inside the shock reservoir, high-pressure nitrogen gas provides IFP (internal floating piston) performance. Each shock absorber is a custom valve for your specific vehicle. The end result is a shock that provides consistent control with excellent heat dissipation. The Jeep JK wrangler front shocks also come with large rubber bushings and easy-to-install lower rubber bushings, as well as brackets to hold the remote reservoir. The rear shocks are also easily installed.
Installation of the lifting kit
We took a day to install Skyjacker’s 2- to 2.5-inch Dual Rate suspension with the new ADX 2.0 Adventure Series shocks on our friend Kenny Garcia’s 2013 two-door Jeep Wrangler Sport. The job is pretty simple, and basically consists of swapping in the coil springs, new shocks, bumpstop extensions front and rear, and a bracket to level the rear track rod after the suspension lift is added (this minimizes rear end shimmy when going fast over large bumps). We also added a steering stabilizer to replace the factory unit. Kenny has removed the rear anti-sway bar from the factory and devised a clever way to disconnect the front anti-sway bar by welding small tabs to the coil spring bucket. Then he loosens the links against the sway bar, flips them over, and screws them into the tab when not in use.
Installation of lifting kit at the front
Following the included instructions, we started with the front suspension by loosening the axle end of the trailing rod and removing the tie rod end of the tie rod from the tie rod. We also opened the metal bracket that holds the factory brake line under the spool bucket. This allowed the brake line to be moved, allowing for more movement when the vehicle is cornered.
We tack welded a washer to the coil mount so we could tie the brake line in place.
With the axle supported and the factory shocks and springs removed, we drilled holes and installed the front bumpstop spacers according to the instructions.
We then installed the new Skyjackers dual rate coil springs and the new shocks.
The hole for the axle end of the track rod was a little enlarged from wear, so we made some tabs of eighth inch sheet steel to weld across the front and back.
Once that was done, we reinstalled the track rod and steering, and torqued the bolts to factory specs.
Rear lift kit installation
With the front unbuttoned, we moved to the rear of the Jeep, where the setup is similar and fairly simple.
Again, support the axle and remove the springs and factory shocks. We disconnected the factory brake lines from the outside of the frame rail to allow the axle to drop enough to remove the springs without damaging the brake lines and ABS lines.
We then installed the new springs, rear bumpstop spacers, and then the new ADX 2.0 shocks.
The final step is to install the tie rod bracket, which holds the tie rod level with the newly added suspension lift. The mount bolts into place, but requires drilling a hole for an additional bolt. We then added some small seam welds to the bracket to keep it from moving.
Since we plan to drive this Jeep rough terrain for years to come, we also grabbed some 3/4 x 1/8-inch steel straps and made some drop mounts for the brake lines. This ensures that the brake lines are not stressed when the Jeep is cornered off-road. It’s probably not necessary on Jeeps that won’t be going off-road much, but gives us a little more peace of mind when we’re on the trail. Finally, we tightened the bolts to factory specifications and installed the tires and wheels.
Time to ride a quad bike
With the new lift complete and a set of 35×12.50R17 tires installed, we headed to our local off-road area to see how the Skyjacker dual-speed coils and Skyjacker ADX 2.0 Adventure Series Shocks performed. The results were everything we could have hoped for.
The spools allow plenty of flexibility (especially with the front anti-sway bar disengaged) and the dual-speed spools offer a smooth ride on pavement, over a dirt road or in a wash. The shocks also felt fantastic, soaking up the washboards and whooping in the dry cleaning we blasted down.