Society didn’t just collapse; it imploded, leaving a crater of destruction. Law and order are just old words from a forgotten time. You and your four-legged companion roll out in the one vehicle you’ve spent years building for this moment: the Ultimate Bugout Apocalypse Adventure Jeep. It’s loaded with supplies, weapons, and the weight of survival itself.

It is a heavy slug, no doubt. Every mile is a battlefield strewn with junk and destruction from the old world. Roads are fractured and clogged with debris. Every route is a path to be carefully navigated. It is not straight and flat, wide and open. Only up, down, around, backwards, and always moving. Churned earth, collapsed bridges, and jagged rock fields stand between you and the next safe camp.

Every obstacle demands power at the wheels, traction on demand, and a drivetrain built for the long haul. This is where the heart of the machine matters most. In this chapter, we strip out the factory arrangement for some Jeep drivetrain upgrades with battlefield-ready gearing from Nitro Gear & Axle and selectable Eaton ELockers front and rear. Because in this new world, the difference between moving forward and getting stuck isn’t luck. It’s about keeping the gears turning when everything else has stopped.

Project Apocalypse Bug Out Jeep Drivetrain Upgrades For Surviving The Wild

If you have been following our Project Apocalypse Bug Out Jeep series, you know this 2018 Jeep JLU Wrangler Sport is not just another weekend trail toy. This rig is our version of the ultimate survival machine. We built it to be a four-wheeled lifeboat built to carry us through the collapse, the chaos, and the untamed backcountry that comes after. Additionally, this vehicle still has to scoot around town as a grocery getter while the norms of current civil society still churn.

Project Recap

So far, the transformation has been radical. We took stock of our starting point and built an inventory plan worthy of a prepper’s dream garage. We’ve upgraded for impossible terrain, mounted a Springfield Armory loadout, and locked down critical gear with Tuffy Security Products. Most recently, the project received an assortment of body armor upgrades and then off-road lighting from Baja Designs after that. Along the way, the Jeep was fitted with 17-inch Black Rhino Abrams wheels wrapped in 35×12.50R17LT Mickey Thompson Baja Legend EXP tires.

Bigger tires were an important part of this Jeep’s survival makeover, but they also changed everything about how power gets to the ground. The factory 3.45 gears in the Dana 30 M186 front and Dana 44 M220 rear axles were no match for the additional rolling mass and increased leverage of our new setup. Left unchecked, that mismatch meant sluggish acceleration, higher transmission stress, reduced crawl capability, and worse fuel economy. All of this is bad news now and worse when you are isolated, running from trouble, and hauling heavy gear into the middle of nowhere.

To resolve current and future issues, we turned to Nitro Gear & Axle for a complete front and rear regear and master install kits, plus their aluminum rear diff cover. We also added Eaton ELockers front and rear, giving us selectable, on-demand locking differentials to maximize traction on any terrain.

Why the Jeep Drivetrain Upgrades Are Critical

When you jump from factory wheels and tires to a set of heavy 35-inch mud terrains, you’re not just changing the look. The OEM factory optimized specifications have been altered, and so have the physics. Larger tires increase the rotating mass and raise the final drive ratio, which in turn reduces torque at the wheels. In simple terms, it takes more effort for the engine to move the Jeep, and you feel it every time you accelerate, climb a hill, or crawl over an obstacle.

This mismatch can strain the transmission, reduce low-speed control, and compromise overall performance. That’s why regearing is one of the most important Jeep drivetrain upgrades after a major tire size increase. By moving from the stock 3.45 ratio to 4.88:1 with Nitro Gear & Axle ring and pinion sets, we bring the RPM range back into the optimal power band. This restores acceleration, improves throttle response, and puts usable torque exactly where it’s needed, whether that’s climbing loose shale or inching through traffic on the last open road out of town.

Jeep Drivetrain Upgrades For Extra Traction On Demand

Locking differentials are another critical category for a survival-ready vehicle. In stock form, most differentials are open from the factory, including our Jeep Wrangler Sport. This means when one wheel loses traction, power is wasted spinning it while the other sits idle. Eaton ELockers solves that by providing a selectable, full mechanical lock at the push of a switch. Equal torque is applied to both wheels on an axle, giving you the ability to claw through slick mud, precarious rock ledges, snow, or loose sand without relying on momentum or wheelspin. We fitted Eaton units front and rear for total control over traction.

Finally, differential protection and cooling are easy to overlook until you crack a thin factory cover on a trail obstacle or overheat your gear oil during a slow, loaded climb. The Nitro aluminum diff cover on our rear Dana 44 M220 increases oil capacity, sheds heat faster than steel, and adds impact protection. In a bug-out scenario where parts are scarce and downtime is dangerous, those benefits could mean the difference between continuing the mission and sitting stranded.

Jeep Drivetrain Upgrades Product Selection

To identify and build a list of Jeep drivetrain upgrades that could handle the Apocalypse Bug Out vehicle’s new profile, we consulted with various product manufacturers as well as our expert drivetrain specialist from T.A. Auto and Diesel Repair out of Wichita Falls, Texas who would perform the installation.

The following components are our exact parts list, all of which are designed and compatible with our OEM axle arrangement:

Dana 30 M186 Nitro Gear & Axle Front 4.88 Ring and Pinion Kit

• Part Number: D30JK-488-NG
• Material: 8620 steel gear forgings
• Pinion Spline: 24
• Tooth Count: 39/8
• Features: Precision-machined, heat-treated, CNC triple-lapped, Rockwell tested for hardness. Designed to restore lost performance from larger tires and improve crawl ratio.
• Benefits: Returns drivability to near-stock feel with 35-inch tires, improves throttle response, and allows precise control in technical terrain.

Dana 44 M220 Nitro Gear & Axle Rear 4.88 Ring and Pinion Kit

• Part Number: MKM220-JL-488-NG
• Material: 8620 steel gear forgings
• Tooth Count: 39/8
• Features: Same manufacturing standards as OEM gear suppliers, precision-machined and tested for quiet, reliable operation.
• Benefits: Matches front axle gearing for proper driveline function, increases torque multiplication for better off-road performance, and towing.

Nitro Gear & Axle Master Install Kits

• Front Kit (Dana 30 M186): MKM186-JL
  Rear Kit (Dana 44 M220): MKM220-JL
• Contents: Timken and Koyo bearings, carrier shims, pinion shims, seals, crush sleeve, ring gear bolts, marking compound, and Loctite.
• Benefits: Ensures proper gear installation and long-term reliability; uses only high-quality bearings for quiet operation and durability.

Eaton ELockers

• Front (Dana 30 M186): 19818-020
• Rear (Dana 44 M220): 14234-1
• Type: Electrically activated locking differential
• Features: Instant engagement/disengagement with no compressor required, full mechanical lock for both wheels on the axle, factory-fit design for strength and reliability.
• Benefits: On-demand traction control in any condition without the compromises of automatic lockers; maintains normal street manners when unlocked.

Nitro Aluminum Differential Cover – Dana 44 M220

• Part Number: NPM220-COVER
• Material: Reinforced aluminum with finned design
• Features: Increased oil capacity, improved heat dissipation, recessed bolt design to prevent trail damage, corrosion resistance, fill and drain plugs for easy service.
• Benefits: Extends gear life under heavy loads and extreme conditions; protects the differential from impact damage in rough terrain.

Jeep Drivetrain Upgrades Install Overview

For a job like this, professional installation is strongly recommended. Setting up our Jeep drivetrain upgrades with gears and lockers requires precision tools, proper torque specs, and dial indicators to get the correct gear mesh pattern. To ensure our bugout vehicle will last from here until eternity, the boys at T.A. Auto and Diesel Repair, a trusted local driveline shop, took on the job with care and consideration.

Having a trained and experienced eye involved throughout the whole process was another benefit for a thorough inspection. All of the mechanical parts have some kind of set lifespan. Whenever you have the opportunity to check things out and get eyes on what is typically hard to get to can be revealing. Worn bearings, metal shavings, grooves and gouges, leaking seals and gaskets, and any number of other issues that might cause bigger problems down the road should be addressed.

Luckily for us, most everything checked out and came apart and back together without too much fuss. Here’s the loose breakdown of the process presented below. We show images of the front axle differential removal and assembly. The detailed process of the front and rear is presented in the featured article gallery.

Step 1: Disassembly

The Jeep was safely lifted, and the front and rear axle assemblies were drained of fluid. Driveshafts were disconnected from the yokes. Differential covers were removed, exposing the ring and pinion assemblies.

Brake calipers and rotors were removed for better access. Axle shafts were pulled, and the carrier assemblies with ring gears were carefully removed and labeled for reference.

Step 2: Removing the Stock Gears and Bearings

Pinion yokes were pulled using an impact and puller setup. Factory 3.45 gears and bearings were removed from both the Dana 30 M186 and Dana 44 M220. This was also the time to inspect axle seals and housing surfaces for any wear or damage.

Step 3: Installing the Eaton ELockers

The new Eaton ELockers replaced the factory carrier assemblies. The locker housings were prepped with the Nitro-supplied carrier bearings from the master install kits. Wiring leads for the ELockers were routed through the housings and sealed with grommets and silicon to prevent moisture intrusion.

Switches for the lockers were mounted in the cabin, with wiring routed through the loom to protect against abrasion in off-road environments.

Step 4: Setting Up the Nitro Ring and Pinion Gears

Each axle received its matched Nitro Gear & Axle 4.88 ring and pinion set. Pinion depth was set using shims, and new crush sleeves were installed. Pinion bearings were pre-lubed, and pinion preload was set according to spec.

Ring gears were bolted to the Eaton locker cases with thread locker applied, then torqued in sequence. Backlash and gear contact patterns were checked using marking compound to ensure proper setup.

Step 5: Installing the Rear Nitro Aluminum Diff Cover

With the gears set, the rear Dana 44 M220 received its new Nitro aluminum cover. The cover’s recessed bolt design helps prevent trail damage. The material, design, and construction help dissipate heat. Each of these critical benefits helps with extended low-speed crawling, where oil temps can climb.

Fresh gear oil was added to both axles. We noted more fluid was required in the rear with the increased capacity allowed by the new cover.

Step 6: Final Assembly and Testing

Axle shafts, brakes, and driveshafts were reinstalled. All wiring connections for the lockers were tested, ensuring both front and rear units engaged and disengaged cleanly.

After reassembly, the Jeep was taken for a careful break-in cycle. Sustained high speeds were avoided for the first 500 miles before the first gear oil change. This is always a recommended step vital for long gear life.

Do The Jeep Drivetrain Upgrades Payoff?

With the Nitro gears and Eaton lockers in place, the Bug Out Jeep now drives like it should with the 35s — crisp acceleration, improved crawl control, and selectable traction that can get us through terrain most rigs with stock drivetrains and upgraded tire arrangements would have to turn around and avoid.

If the world goes sideways, we can roll into the backcountry knowing the drivetrain won’t be the weak link. In the meantime, it just makes every trail day and getting around town more capable and more fun — apocalypse or not.