Rusty’s 3.75" Advanced Kit for the New JL Wrangler was specifically developed to deliver the on-road performance people expect from the JL combined with the ultimate flex and control off the pavement. We weren't the first JL kit to be released, but we feel we have the best. Where others rushed their prototypes to market with little to no testing, we invested the time and effort to thoroughly test everything. The result is what we feel is the best kit in the industry, and there's no need to accept anything less.
In late 2017 we started on coil spring and shock designs as we got small bits of information. In late January 2018, we received our first Rubicon and a Sport, this is when we got ready to get to work. With the Jeep JL being totally redesigned from the departing JK Wrangler, everything was different. Ride quality, handling, and suspension travel were greatly increased on the new JL Wrangler, but it also meant that nothing that was learned from the JK applied to the JL. It was our job to design a coil spring that would ride as good if not better, not lose any of the outstanding road handling manners, increase the lift height for larger tires and add more suspension travel. We knew the challenge ahead of us wasn’t going to be quick, nor was it going to be easy. We also spent countless man hours on the computer designing with 3-D modeling. Now with over a year in design and real-world testing, we feel we have designed and engineered one of our best kits yet.
We developed a dual rate progressive front and rear coil spring. These springs were started from scratch and are a totally different design and spring rate from the departing JK. This extensive development takes time and is costly to design and build. Beware of many manufacturers and their one-size-fits-all mentality by using springs that are designed for other applications. It's certainly cheaper to borrow designs from previous platforms, and it gets you to market more quickly, but that doesn't make it right. Rusty’s JL coils springs were developed corner-specific, meaning that every spring is different on each corner of the vehicle, just as built from the factory. Corner-specific springs mean you can be assured the ride height of the vehicle will be correct, with no cheesy offset spacers needed to keep the vehicle level or reduce spring bowing. The Rusty’s 3.75" kit will give you the clearance on a Rubicon JL to fully flex it with 37-inch tires off road and not have any fender rub, no inner fender rub. You can also easily run a 40-inch tire but bump stops are recommended for vehicles going off road.
It is important to check the brake package that is installed on your JL Wrangler as the HD Brake Package was offered as an upgrade option for sport and sahara models. Please reference the image below to determine the correct brake hose selection for your application if you choose to purchase the optional brake hoses to your suspension kit.