{"product_id":"jks-jspec128frs","title":"JKS J-Krawl 3.5\" Lift Kit w\/ Fox 3.0 IBP | HD Coils | 2018–2026 Jeep Wrangler JL 4-Door","description":"\u003ch2\u003eJKS J-Krawl 3.5\" Lift Kit w\/ Fox 3.0 IBP | HD Coils | 2018–2026 Jeep Wrangler JL 4-Door\u003c\/h2\u003e\n\n\u003ch3\u003eIs This for You?\u003c\/h3\u003e\n\u003cp\u003eYou're building the ultimate dedicated crawler on an accessorized JL 4-Door Unlimited and you want the highest-spec Fox shock available in the J-Krawl 3.5\" HD lineup. The JSPEC128FRS delivers JKS J-Krawl crawler geometry with Fox 3.0 Internal Bypass (IBP) shocks and HD coil springs. The 3.0\" body's increased oil volume provides superior heat dissipation under the accessory load's increased dynamic demand, and the internal bypass ports deliver progressive damping that transitions smoothly between maximum articulation compliance at slow crawler speeds and progressive control at higher trail speeds. HD coils maintain ride height under steel bumpers, winch, and rock rails.\u003c\/p\u003e\n\n\u003ch3\u003eThe Result\u003c\/h3\u003e\n\u003cp\u003e3.5\" of lift with JKS J-Krawl crawler geometry — engineered for maximum droop travel and articulation on technical terrain. HD coils maintain ride height under accessory loads. Fox 3.0 IBP shocks deliver progressive damping through internal bypass ports: soft and compliant at low shaft velocities for maximum articulation on slow rock sections, progressively firmer at higher velocities for trail control. The 3.0\" body's increased oil volume provides superior heat dissipation on sustained technical terrain under the accessory load's increased dynamic demand.\u003c\/p\u003e\n\n\u003ch3\u003eVerified Fitment (OFAS Standard)\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFits:\u003c\/strong\u003e 2018–2026 Jeep Wrangler JL 4-Door (Unlimited) — Gas Models (2.0T, 3.6L)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDoes NOT fit:\u003c\/strong\u003e JL 2-Door | JL EcoDiesel | JL 4xe Hybrid | JK (any year) | Gladiator JT\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCoil Note:\u003c\/strong\u003e HD Rate — engineered for accessorized JL 4-Door builds with steel bumpers, winch, or rock rails. Use JSPEC127FRS (Std-Rate) for stock-weight builds.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eSystem Specifications\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eLift Height: 3.5\"\u003c\/li\u003e\n\u003cli\u003eSystem: J-Krawl (crawler-specific geometry, maximum articulation)\u003c\/li\u003e\n\u003cli\u003eShock: Fox 3.0 Internal Bypass (IBP) — 3.0\" body diameter, internal bypass ports, progressive damping\u003c\/li\u003e\n\u003cli\u003eCoil Rate: HD — tuned for accessorized JL 4-Door crawler builds\u003c\/li\u003e\n\u003cli\u003eControl Arms: JKS J-Krawl geometry-corrected control arms\u003c\/li\u003e\n\u003cli\u003eSKU: JSPEC128FRS\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eInstallation \u0026amp; Fabrication Notes\u003c\/h3\u003e\n\u003cp\u003eProfessional 4-wheel alignment required post-installation. Torque all control arm hardware to JKS specification after a 500-mile break-in. The Fox 3.0 IBP's larger body diameter requires clearance verification against skid plates, rock rails, and body panels before install — confirm clearance with OFAS before ordering. The J-Krawl system is designed for locker-equipped builds — confirm front and rear locker compatibility with OFAS before finalizing your build spec. No cutting or welding required for standard JL 4-Door gas applications.\u003c\/p\u003e\n\n\u003ch3\u003eWheel \u0026amp; Tire Fitment\u003c\/h3\u003e\n\u003cp\u003eEngineered for 37\"+ tires on a dedicated crawler build. Recommended backspacing: 4.5\"–4.75\" on a 17\"×9\" or 18\"×9\" wheel. The JL 4-Door's longer wheelbase provides more fender clearance than the 2-Door at 3.5\" of lift — confirm tire brand and tread width before finalizing wheel selection. Contact OFAS for 40\" tire clearance confirmation.\u003c\/p\u003e\n\n\u003ch3\u003eEngineering Question\u003c\/h3\u003e\n\u003cblockquote\u003e\u003cp\u003eRunning Fox 3.0 IBP shocks with HD coils on a J-Krawl 3.5\" JL 4-Door crawler build with steel bumpers, winch, and rock rails — how does the accessory load's increased dynamic demand affect the IBP bypass port engagement threshold compared to the same shock on a stock-weight JL 4-Door J-Krawl 3.5\" with standard-rate coils? The accessory load increases the static and dynamic load on the front shocks, which means the shock reaches higher shaft velocities per obstacle than on a stock-weight build. This shifts the bypass port engagement threshold — the shock may transition from bypass to main valving at a lower trail speed on the accessorized HD-coil build than on the stock-weight standard-rate build. Contact OFAS with your total accessory weight and primary terrain and we'll confirm the IBP bypass tuning that's right for your specific accessorized JL 4-Door J-Krawl 3.5\" configuration.\u003c\/p\u003e\u003c\/blockquote\u003e","brand":"JKS Manufacturing","offers":[{"title":"Default Title","offer_id":51444643463489,"sku":"JSPEC128FRS","price":8335.82,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0974\/1284\/1793\/files\/JSPEC128FRS_0-BKWD.jpg?v=1772726274","url":"https:\/\/obsidianforgedautosupply.com\/products\/jks-jspec128frs","provider":"Obsidian Forged Auto Supply","version":"1.0","type":"link"}