Rusty's JL Wrangler 3.75" Advanced Kit


  • Brand: Rusty's Off Road Products
  • Availability: In Stock
  • Part Number: RK-375A-JL-RUB-GAS

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.


  • Front Progressive Rate Coil Springs
  • Rear Progressive Rate Coil Springs
  • Adjustable Front Upper Control Arms with Forged Flex Ends
  • Your choice of Adjustable Front Lower Control Arms with Forged Flex Ends or Forged Rubber Ends
  • Your choice of Adjustable Rear Upper Control Arms with Forged Flex Ends or Forged Rubber Ends
  • Your choice of Adjustable Rear Lower Control Arms with Forged Flex Ends or Forged Rubber Ends
  • Adjustable Front Track Bar
  • Adjustable Rear Track Bar
  • Front Track Bar Frame Mount Brace
  • Front and Rear Extended Sway Bar Links
  • Front Brake Line Extension Brackets
  • Front Upper and Lower Coil Spring Isolators


  • Progressive Dual-Rate Coil Springs Front and Rear
  • Coils specifically developed from the JL, not borrowed from previous platform designs
  • Maintains factory ride quality while making room for a larger tire and wheel package
  • Adjustable upper and lower control arms with Forged Flex Joints front and rear for the ultimate in adjustability and flex
  • Extended front and rear sway bar links maintain factory sway bar functionality
  • Available shock absorbers are tuned to work with spring rate

* There is much talk about a driveshaft being needed for this lift, we have ran many JL's with stock shafts and have had no wear problems, a lot of this depends on how you use the vehicle. Just as it would stock, if you wheel a lot and use the vehicle in harder off road trails and situations, it will wear the driveshaft faster and then you will need to replace and we suggest a aftermarket HD shaft. But is it necessary for you to replace the driveshafts to install this kit, no not at all. Rusty's also offers a complete line of aftermarket HD driveshafts when that time comes.  

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