ATS 850RE 8-Speed 8HP Conversion Kit for 2012–2018 Jeep Wrangler JK 3.6L — JL Transfer Case Compatible

Unleash Modern 8-Speed Performance in Your 2012–2018 Jeep JK

The ATS 850RE 8-Speed Transmission Conversion Kit is the ultimate upgrade for Jeep Wrangler JK owners looking to bring next-generation drivability, torque control, and OEM-grade refinement to their off-road machine. Designed for seamless integration with your 3.6L Pentastar-powered JK (2012–2018), this complete system replaces the factory 5-speed NAG1 automatic with the advanced 850RE 8-speed automatic found in the JL Wrangler. With full support for factory electronics, zero tuning required in most builds, and full plug-and-play operation, ATS makes it possible to experience the 8HP/ZF-based transmission architecture without changing the character of your Jeep — only how well it drives.

This kit is engineered from the ground up to deliver smooth shift logic, aggressive torque multiplication, higher overdrive efficiency, and unmatched off-road control — all while retaining your factory dash functions, gear selector, transfer case, and interior layout. Whether you're daily driving, towing, climbing, or crawling, the 850RE transforms your Wrangler into a smarter, smoother, and more capable machine.

Why the 850RE Transmission?

The 850RE — derived from ZF’s highly respected 8HP family — is widely regarded as one of the best automatic transmissions in the industry. Jeep and Ram have used it across numerous models for a reason: it’s fast, refined, durable, and efficient. Compared to the outdated NAG1 or NSG370 transmissions commonly found in JKs, the 850RE offers substantially improved shift speed, gear spread, and low-speed control. With a 7.05 overall gear spread, this unit provides both aggressive first and second gear crawl ratios and efficient cruising gears for fuel economy and RPM reduction.

Unlike legacy transmissions, the 850RE uses advanced clutch-to-clutch shifting, multi-plate friction systems, and computer-driven torque demand modeling to make every shift precise and purposeful. It enables multi-gear downshifting (like 8–6 or 8–4), seamless power delivery, and faster tap-shift response — all managed through ATS' proprietary Translator module that makes everything work natively with your JK electronics.

Full OEM Integration — No Tuning, No Cutting, No Compromises

What sets ATS apart from every other swap kit is simple: full OEM integration. The ATS Translator module connects your Jeep’s ECM, TCM, BCM, brake systems, cluster, cruise control, traction management, and shifter — preserving all factory features and making your 8-speed JK function like a showroom-stock vehicle.

Your factory NAG1 console shifter is reused to control the 850RE, retaining manual +/- tap-shift functionality, auto lockout protection, reverse inhibitor at speed, and accurate shift display. Gears 1–6 show natively on your cluster; 7 and 8 are displayed as “1” and “2,” just as they are on JL applications. ABS, speedometer, tachometer, and remote start all function as expected. This is not a partial or hack job solution — it's complete and seamless, backed by ATS’ decades of drivetrain control innovation.

Built for the 3.6L Pentastar — Perfect for V6 JKs

This particular kit (SKU: 319-916-8380) is engineered specifically for 2012–2018 Jeep JK and JKU models equipped with the 3.6L V6 ERB Pentastar engine. It’s optimized for use with the JL-style transfer case, allowing JK owners to source or reuse a JL 4x4 system while upgrading to the 850RE. The electronics, brackets, mounts, harnesses, and programming are tailored to work with your factory engine calibration and OEM vehicle architecture.

Want to supply your own transmission? ATS supports that too — but this complete version includes an ATS-inspected, dyno-tested 850RE transmission, Torque Converter, Translator module, wiring harness, brackets, cooler lines, and installation hardware. All you need is a JL transfer case and driveline adjustments to complete the swap.

Why Swap the NAG1?

Let’s face it — the NAG1 5-speed automatic was already outdated when it debuted in the JK lineup. With limited gear ratios, sluggish shift mapping, and poor performance under torque loads or large tires, the NAG1 holds back the true potential of your Jeep. Even the strongest rebuilds can’t match the mechanical and software-based refinement of the 850RE.

ATS’ 8-speed conversion offers major benefits in every driving scenario:

• Low-speed crawl power with deeper first gear (4.71:1)
• Smoother on-road driving with seamless gear transitions
• Better fuel economy with higher overdrive gears (0.67:1 in 8th)
• Improved throttle response and torque application
• Fully automatic or manual tap-up/tap-down modes
• Reduced engine strain and RPMs during highway use
• OEM electronic behavior — cruise, ABS, traction all retained

What’s Included in the Complete Conversion Kit

This is the full version of the ATS 850RE Conversion Kit with transmission and torque converter, specifically configured for JL transfer case compatibility. Components include:

• ATS 850RE 8-Speed Transmission (Remanufactured, E-Dyno Tested)
• ATS TruLok Torque Converter Assembly
• ATS Translator (Gateway) Module
• Complete OEM-Grade Plug & Play Wiring Harness
• ATS Mounting Brackets and Adapters
• Transmission Cooler Lines and Hardware
• Shifter Adapters and Plug-in Harness for OEM NAG1 Console
• Vehicle-specific install hardware for JL Transfer Case Setup

This kit requires the use of a JL Wrangler Transfer Case (customer-supplied) and minor driveline adjustments (approximately 5” of length due to transmission housing). All core vehicle functions remain unchanged and operate as if the Jeep shipped from the factory with the 850RE drivetrain.

Installation Overview

Installation can be completed by any experienced Jeep technician, off-road shop, or advanced DIY builder. The plug-and-play nature of the electronics means no custom wiring, soldering, or calibration is required. The entire electronics portion installs in less than 1 hour. ATS provides detailed instructions and support, and remote assistance is available for configuration of the Translator via PC interface if needed.

Gear Ratio Comparison

The most noticeable driving improvement is in the gear ratios. Here's how the 850RE stacks up against the JK factory transmission options:

850RE Gear Ratios

Gear	850RE (ZF 8HP)	NAG1 (W5A580)
1st	4.71 : 1	3.59 : 1
2nd	3.14 : 1	2.19 : 1
3rd	2.10 : 1	1.41 : 1
4th	1.67 : 1	1.00 : 1
5th	1.29 : 1	0.83 : 1
6th	1.00 : 1	—
7th	0.84 : 1	—
8th	0.67 : 1	—
Reverse	3.30 : 1	3.16 : 1

The 850RE provides a dramatically lower first gear for better off-road performance and a higher overdrive gear for highway efficiency. The spread is significantly improved — from the NAG1's 4.32 ratio spread to the 850RE’s 7.05 spread.

Compatible Platforms

This kit is designed for 2012–2018 Jeep JK Wrangler and JKU models equipped with the 3.6L V6 Pentastar engine. It requires use of a JL-style transfer case and assumes NAG1 automatic as the original transmission (manual transmission applications may require additional hardware).

Who This Is For

If you want your JK to feel like a JL in all the right ways — smoother, faster, more capable, more responsive — the ATS 850RE conversion is the solution. Whether you’re chasing better crawl ratios, smoother overlanding, or a smarter highway experience, this is the most complete, factory-like drivetrain transformation available for your Jeep.

The ATS Advantage

With decades of innovation in diesel and gas transmission control, ATS leads the aftermarket in factory-grade integration. This conversion system isn’t just another swap — it’s a clean-sheet re-engineering of what your JK should have been. With 100% retention of factory electronics, zero ECM tuning, and OE shifter re-use, it’s the most advanced and complete 8-speed swap on the market.

Backed by ATS’ exclusive warranty, technical support, and product development, this is not a patchwork solution — it's a true OEM+ upgrade for the modern Wrangler builder.