Jeep Wrangler JK Evo Lever Suspension System - Evolution Of The SpeciesPosted in How To: Suspension Brakes on January 1, 2009
What do you do when you want big travel from the rear of your JK, but aren't ready to take the Sawzall to your new rig to make room for that shock hoop, compromising your cargo compartment or body integrity? Well, we have the answer for you in the form of Off Road Evolution's Evo Lever cantilever rear suspension system, an innovative evolution of the Jeep Wrangler JK suspension system.
For those of you not familiar with a cantilever-style suspension system, it is a design that uses a lever that is only supported on one end, while the opposite end takes the suspension movement, allowing the shocks to be positioned parallel to the ground in a compact push/pull arrangement.
The Evo Lever upgrade is designed to work with any aftermarket short- or long-arm kit and combines 8-inch-travel King 2-inch Pre Runner Series coilovers (although just about any off-the-shelf 8-inch reservoir shock will work if your brand loyalties lie elsewhere), preloaded with Off Road Evolution's proprietary valving. The coilovers mount to a trick 3/16-inch rear subframe on the frame side and cantilever arms on the axle side. The kit is available in either a weld-on or a bolt-on configuration and is easily installed in half a day with the right tools, while the bolt-on kit can be returned to stock. The Evo Lever will give you up to 14 inches of vertical wheel travel and can even be upgraded for those who want to go huge to the Double Throw Down option that will let you run triple bypass shocks. While the standard suspension setup is designed for mixed use, Off Road Evolution can adjust the suspension tune to favor high-speed wheeling or slow-speed crawling, whatever you prefer.
The Evo Lever also increases ground clearance and is height adjustable. Off Road Evolution says 42-inch tires will fit if you decide to go with a long-arm kit, while short-arm kits are limited to 37-inch tires. One other item of note, you will need an aftermarket exhaust setup as the Evo Lever installs under the body where the muffler resides from the factory.
Mel Wade, owner of Off Road Evolution, invited us to document the install on a customer's JK Unlimited undergoing the transformation at his facility in Fullerton, California, and we were impressed with how well this kit has been engineered and how quickly the Evo Lever was able to be installed.
How Does It Work?
This JK Unlimited was equipped with factory upper arms, adjustable lower short arms, and 37-inch tires with Off Road Evolution's Evo coilover system on the front. On Off Road Evolution's 30-degree ramp, the complete Evo system proved to be highly flexible, achieving a score of 681. That equates to an RTI score of 995 on a 20-degree ramp. For comparison we ramped a stock '07 JK at 706. We ramped this rig straight on with street pressure in the tires, and while RTI is only one measurement of a suspension performance, we were impressed with the articulation this JK ended up with.
While we didn't get to take the kit on the trail, we did get some seat time on the pavement, hitting dips at speed and maybe even abusing a curb or two in the process. We can report that the ride is very comfortable in controlled situations, and the Off Road Evolution suspension system felt very stable at speed, breathing nicely over undulations and soaking up minor and major road imperfections with ease, transferring limited impact to the passenger compartment. We are looking forward to trying out the Evo Lever in the dirt at the first opportunity.