JKS JSPEC159KFA 3.5in J-Konnect FOX Diesel 392 Lift Kit Jeep Wrangler JL 4-Door

Vehicle Fitment

• 2018-2026 Jeep Wrangler JL Unlimited 4-Door with 3.0L EcoDiesel V6 engine, 4WD
• 2021-2026 Jeep Wrangler JL Unlimited Rubicon 392 with 6.4L V8 engine, 4WD

Fitment Notes

• Diesel and Rubicon 392 engines only - for gas-engine (3.6L/2.0T) JL 4-Door J-Konnect 3.5" see JSPEC123KFA
• 4-Door (Unlimited JL) only
• Does not fit 2021-2026 Jeep Wrangler JL 4xe (plug-in hybrid) models
• HD front coil springs (JSPEC1352) are included as standard - the heavier Diesel and 392 front end requires the HD rate to achieve correct lift height and ride quality
• Factory wheels cannot be reinstalled without wheel spacers after lift
• Maximum recommended tire size: 35x12.50 on 17x9, 18x9, or 20x9 wheels with 5" backspacing (Sport/Sahara/Willys); 37x12.50 (Rubicon with 5" backspacing)

Features

• JSPEC HD dual-rate front coil springs (JSPEC1352) and standard-rate rear coil springs (JSPEC1359) specifically tuned to account for the heavier front weight of the EcoDiesel V6 and 6.4L V8 engines
• Custom-valved FOX 2.0 Adventure Series IFP monotube gas shocks matched to this Diesel/392 JL J-Konnect 3.5" system
• Front and rear J-Link lower control arms (heavy-duty 2" x .250-wall DOM tubing) add serious strength over factory arms while correcting front caster and rear wheelbase
• OE-style rubber bushings at both J-Link arm ends minimize NVH for a quiet, street-friendly ride
• JKS front adjustable track bar and rear track bar bracket correct axle positioning at lifted ride height
• JKS2033 Quicker Disconnect front sway bar links unlock up to 30% more front axle articulation on the trail
• Rear extended sway bar links correct operating angle and improve strength at lifted height
• Front and rear bump stop extensions properly limit suspension up-travel at lifted height

Specifications

• Lift Height: 3.5 inches
• Platform: Jeep Wrangler JL Unlimited 4-Door - EcoDiesel V6 and Rubicon 392 V8
• System Level: J-Konnect (adds J-Link lower control arms over J-Venture)
• Shock Series: FOX 2.0 Adventure Series IFP (custom-valved; front FOX98450323, rear FOX98450327)
• Control Arm Construction: 2" x .250-wall DOM tubing, fixed length J-Link lower arms (JKS1671)
• Front Spring: JSPEC1352 HD Rate (diesel/heavier-engine specific)
• Rear Spring: JSPEC1359 Standard Rate
• Max Recommended Tire Size: 35x12.50 (Sport/Sahara/Willys); 37x12.50 (Rubicon)
• Recommended Wheel Backspacing: 5 inches
• Installation Type: Bolt-on, no cutting or drilling
• Warranty: Limited Lifetime (JKS components); FOX Shocks covered by FOX limited warranty
• Made in USA

Included Components

• 2x JSPEC HD Dual-Rate Front Coil Springs (HD Rate - JSPEC1352, Diesel/392 specific)
• 2x JSPEC Dual-Rate Rear Coil Springs (Standard Rate - JSPEC1359)
• 2x FOX 2.0 Adventure Series IFP Front Shocks - FOX98450323 (custom-valved)
• 2x FOX 2.0 Adventure Series IFP Rear Shocks - FOX98450327 (custom-valved)
• 2x Front J-Link Lower Control Arms (fixed length, 2" x .250-wall DOM - JKS1671)
• 2x Rear J-Link Lower Control Arms (fixed length, 2" x .250-wall DOM - JKS1671)
• 1x JKS Front Adjustable Track Bar (JKS1621)
• 1x Rear Track Bar Bracket
• 1x Pair JKS2033 Quicker Disconnect Front Sway Bar Links
• 1x Pair Rear Extended Sway Bar Links
• 1x Set Front and Rear Bump Stop Extensions
• 1x Installation hardware pack (JSPEC1311 J-Konnect Main Box Kit)

Product Description

The JKS JSPEC159KFA is a complete 3.5" J-Konnect suspension lift system engineered specifically for 2018-2026 Jeep Wrangler JL Unlimited 4-Door models equipped with the 3.0L EcoDiesel V6 or 6.4L Rubicon 392 V8. The critical difference from the gas-engine JSPEC123KFA is the front coil spring: this kit uses the HD-rate JSPEC1352 front springs instead of the standard JSPEC1351, accounting for the substantially heavier front-end weight of the diesel and V8 powerplants. Running standard-rate gas-engine springs under a Diesel or 392 front end will result in insufficient lift height and degraded ride quality - this kit is built to get it right from the start.

J-Konnect's defining upgrade over J-Venture - front and rear J-Link lower control arms fabricated from 2" x .250-wall DOM tubing - is fully present here, correcting front caster and rear wheelbase at 3.5" of lift while delivering a meaningful strength advantage over factory arms. Custom-valved FOX 2.0 Adventure Series IFP shocks pair with the mixed HD-front/STD-rear spring package for a system tuned to the diesel platform's specific weight distribution. A JKS front adjustable track bar, JKS2033 Quicker Disconnect sway bar links, and rear extended sway bar links complete the geometry correction package. Does not fit 4xe models.