We all want stronger, more reliable, and more effective axles. Greater strength can come in the way of a complete bolt-in axle replacement. It can also be had through reinforcement using trusses or by swapping in sturdier ’shafts. Better ’shafts can also create a more reliable axle—one that can take more stress and power without becoming a shattered collection of metal bits.
A change-up in the ring-and-pinion ratio can make your axles better at turning larger and heavier tires and wheels and returning lost power sapped from the engine by the added mass and rolling diameter of bigger rubber. And certainly, limited-slip devices and lockers can make your axles more effective by increasing your Jeep’s ability to maintain traction.
Unless you just got your first Jeep, you know all this, but do you know where to find those axle-beefing products to help you make your Jeep better? Well, that’s where we can help. Below you’ll find a helpful guide to many of the major axle product manufacturers and retailers and a smattering of the many parts they can provide to bring a smile to your face next time you take your rig into the boonies.
A full line manufacturer of axle upgrade and performance drivetrain products for Jeeps, including gear sets and high-strength axleshafts, Alloy USA has a wide range of ring-and-pinion gear sets available for Jeep JK Wranglers. The gear sets are made from high-quality 8620 steel forgings and use Gleason gear cutting technology for precise manufacturing of its products. Axle gear sets available for the Jeep JK Dana 30 and Dana 44 axles include 3.73, 4.10, 4.56, 4.88, 5.13, and 5.38 (5.38 not available for the Dana 30 front axle) ratios. Complete kits (pictured) are available to help with proper installation of the axle gears.
ARB is famous for its sturdy and reliable Air Locker. What you may not know is that in the last few years, this well-known traction device has been upgraded. The ARB Air Locker now features a patented two-piece case design, forged gears, and a five-year warranty. According to ARB, moving away from the old three-piece case delivered a 40-percent increase in static torque strength, eliminated the cylinder cap and moved the air entry to the ring gear side of the unit, allows the side gear to lock directly to the flange cap, speeds up engagement, and the sturdier two-piece case design spans the entire line of applications. The Air Locker’s patented “Time Gear Design” means that the locking mechanism has its spline spacing synchronized with the gear tooth spacing so it locks with maximum tooth surface area.
Offering a variety of gear sets, install kits, and differentials for a number of different vehicles and applications, Auburn Gear can fill your Jeep’s axles with the goods you’re looking for. From its HD and Pro Series (with a bit more bias) limited-slips to its automatically full-locking Max Lock Locker or the ECTED Max (unit for the Dana 44 pictured) series of electronically actuated lockers that go from open-to-lock with the flip of a switch, you are covered when it comes to differentials. Newest to the Auburn Gear catalog of performance differentials are the Dana 70 and Dana 60 ECTED Max units (Dana 44, 35, 30, and AMC 20 units are available too). The ECTED Max Locker gearing is made from aircraft quality 9310 heat-treated billet steel, doesn’t have any shift forks or pins that must be lined up to obtain locker mode, and can be switched on or off “on the fly” at any road speed, taking it from acting as a limited-slip to a full locker.
Currie practically invented the high-performance axle upgrade with its legendary 9-inch, but these days Jeep enthusiasts are most enthusiastic about the Currie RockJock axles for Jeep JK Wranglers. The company produces the RockJock 44, 60, and 70. The RockJock 44 (pictured) is a high-pinion design with a ductile iron center housing that only accepts the larger JK high-pinion 44 gears that feature a larger ring gear than a standard 44, as well as a 29-spline Dana 60 size pinion gear. The tubes are 3-inch diameter, 0.375-inch wall, and heavy duty JK suspension brackets are mounted on this housing for an easy bolt-in installation. The JK Rubicon's electric locker can be used, and Currie's forged JK knuckles are installed. These are completely custom-built units made to order to each customer's specifications and application. Housings don’t include ball joints, cover, or yoke. Axle upgrades are also available for the TJ, YJ, CJ, XJ, and MJ.
While Dana Aftermarket Group (which includes Spicer) has just about everything you might need to kick your axles up a notch, the most recent products to blitz the Jeep market have been its Ultimate Dana 44 (pictured) and Ultimate Dana 60 complete bolt-in axle assemblies. The 44 Front Axle for the Jeep Wrangler JK delivers thicker tubes (5/16-inch), redesigned thicker (1/4-inch) brackets, chomoloy shafts, 1350 U-joints, increased GAWR, and a pinion angle optimized for lifted vehicles among its many attributes. The 60 front and rear axles for Jeep JK applications are even more serious super beef. Among other things, the front 60 offers massive Spicer 70 U-joints, 35-sline 4340 nickel chromoly shafts, and Warn 35-spline hubs, while the rear 60 is a full-floater with upgraded brakes, 35-spline 4340 nickel chromoly shafts, and 3 1/2-inch diameter/0.390-inch-wall tubes.
A retailer specializing in performance drivetrain products (hence the name Drivetrain Specialists), this company is a veritable storehouse of axle upgrade products, information, and advice. With product offerings from more manufacturers than you can count on all your fingers and toes, it can offer just about everything, including third members, air lockers, axleshafts, full install kits (pictured), pinion supports, seals, shims, spyder gear kits U-joints, and yokes. If you can’t find it here, it’s probably not made.
New in Dynatrac’s buffet of axle upgrades are its ProRock XD60, JK44 Pro Axleshaft Kits, and a product that came out of collaboration with ARB: a 40-spline ARB Air Locker specifically designed for the ProRock XD 60. The gnarly ProRock XD60 axle offers a nodular iron center section available with larger pinion and carrier bearings, a 10.1-inch reverse-cut high-pinion ring gear, 1550 U-joints, and 30-series CV joints. Along with stronger wheel studs, billet ABS tone rings, and billet steel retainers and retainer studs. The JK44 Pro Axleshaft Upgrade Kit (pictured) brings 30-spline 4340 chromoly shafts and 1350 u-joints to your factory front 44, and 35-spline shafts to your rear 44. The 40-spline ARB Air Locker (only available from Dynatrac) offers a new case with a stronger carrier bearing trunnion, and it accepts Dynatrac’s ProRock XD oversized carrier bearings.
Eaton Performance offers a handful of performance differentials that can liven up your Jeep JK. It manufactures the Detroit Truetrac (helical-gear limited-slip), Eaton Posi (clutch-pack limited slip), the venerable Detroit Locker (the original badass locker), and the ELocker and ELocker4. Applications for the ELocker will fit almost every Jeep axle (front and rear) from AMC 20 to Chrysler C-clip to Dana 44. The all-new ELocker 4 (pictured) is for front and rear Dana 60 and 70 axles. The ELocker and the E-Locker4 (a much beefier design with a 0.14-second engagement time) are four-pinion designs that operate as open differentials until electrically activated by a dash switch, upon which they instantly turn into fully locked units. They remain locked in forward or reverse, and accept ring gears in a broad range of ratios to fit the needs of hard-driving recreational off-roaders.
G2 Axle & Gear
Jeep owners have a lot of options when it comes to axle upgrade hardware, and G2 can help in a big way. Just a few of the many products available from G2 Axle & Gear are the G2 Axle Truss systems, Core 44 complete bolt-in axle assemblies, G2 Core Locker, and G2 Placer Gold Axles. The G2 Axle Truss is American-made and CNC laser-cut from 3/16-inch steel and fit Dana 30 or Dana 44 (pictured) axles with either stock height track bar brackets or raised track bar brackets for lifted applications. G2 Core 44 bolt-in axle assemblies build on upon the larger rig-and-pinion gears sets in the JK Dana 44, use 3-inch diameter, 5/16-inch-wall tubes with reinforced inner knuckles, and 1-1/2-inch, 35-spline shafts. The G2 Selectable Locker is an all-new air-actuated locker with a manual fail-safe mode that can lock or unlock the differential, and applications for 30- and 35-spline Dana 44 (including the JK 44) are available. G2 Placer Gold Axles for the Jeep JK are forged 4340 chromoly, gold-zinc plated for corrosion resistance, and accept 1350 U-joints.
G2 Axle & Gear
Gear Tech HD
Gear Tech HD offers a number of axle upgrade products for Jeeps, but one of the most popular is its heavy-duty GT 44 axle with a nodular housing that has upper and lower pinion oil galleys so it can be run upside down in low-speed applications. The GT 44 has full-float spindles with Dana 60-size wheel bearings and full-float hubs. It can be fit with either one-piece flanged axles or double-spline with drive flanges. Gear Tech HD also offers a disc brake system to go with it. The housing can be purchased separately or Gear Tech HD can custom-build it to the customer’s specs.
Gear Tech HD
Nitro Gear & Axle
Nitro Gear has axle upgrade goodies for nearly every Jeep out there, including chromoly shafts for Wagoneer axles. However, very popular are the 4.10-ratio ring-and-pinion sets for the front and rear axles under the Jeep WK (’05-’10 Grand Cherokee). These are heat-treated 8620 forged steel gears that are CNC triple-lapped and Rockwell tested for hardness. The Nitro Big Pinion (pictured) conversion kit for typical Dana 44 and JK 44 axles features a 24-spline (Dana 60 size) 1-1/4-inch pinion shaft (stock is 1.11-inch) and an 8.875-inch ring gear (stock is 8 1/2-inch), and comes in select ratios. Nitro also offers front Dana 44, D44, ’07-’14 and rear Dana 44, D44, ’07-’14 non-Rubicon chromoly JK shaft kits. Rear kits come assembled with bearings, ABS tone rings, seals, and retainers installed, so they’re ready to install. Dana 30/44, D30/44, Jeep JK (up to 35-spline) front axletube sleeves, and ’07-’14 Jeep JK front knuckle gusset and lower control arm skidplate kits are also hot sellers.
Nitro Gear & Axle 916/673-6464
Quite possibly the ultimate retailer of parts and accessories for Jeeps is Quadratec. It lists more parts on its website than a Cray XK7 supercomputer could count in a day, but that doesn’t mean you’ll have trouble finding what you want. You can easily shop by part category, part number (if you know that already), or part description, and the help line is extremely “helpful.” In the Quadratec Jeep Driveline section, you’ll find just about anything from full bolt-in axle assemblies to axleshafts to ring-and-pinion gears sets to seal and bearing kits from major manufacturers such as ARB, Dana/Spicer, Dynatrac, G2, or RCV to upgrade your axles. It was easy for us to pull up the Crown Automotive pinion shim kit for a ‘76-‘86 Jeep CJ with a Dana 30 front axle (pictured) we were looking for.
High-performance axleshafts are what RCV is all about, and its Ultimate CV Axles for the Jeep JK are designed to replace the U-joint-style front axleshafts and eliminate that “weak link” in your Jeep’s drivetrain. The RCV CV-design helps eliminate binding at hard angles and, according to RCV, eradicate steering wheel “shimmy.” The company’s patented Spherical Sealing Technology can provide greater protection from tears and punctures than the typical rubber CV boot. These ’shafts are made from 4340 chromoly and designed to fit the factory Dana 30 front axle, as well as JK Rubicon Dana 44 front axle (pictured). As a further upgrade to the factory front axleshafts, RCV Performance also offers its Ultimate CV Axle in a 300M material and a 35-spline inner upgrade for use with 35 spline lockers. In addition to its beefy front axle upgrades, RCV Performance now also offers the Ultimate JK 300M Rear Axle in a direct-replacement 32-spline design or a 1 1/2-inch 35-spline ’shaft. Dual bolt-pattern threaded flanges support factory 5x5 or the 5x5.5 bolt pattern for upgraded-hub vehicles. Full-floater rear axles are also offered in custom spline counts and lengths.
Revolution Gear & Axle
Revolution Gear & Axle can cover almost all your axle upgrade needs. Its Dana 60 gear sets are made from 8620 steel and are precision heat-treated to OEM specifications. All Revolution ring-and-pinion sets are backed by the company’s two-year warranty against defects. Revolution gears are also double-lapped and, in some cases, triple-lapped for flawless set up, smooth running, and longer life. With products that have been proven on the street, track, and in the dirt for more than a decade, you can count on Revolution Gear & Axle to offer a wide variety of high-quality parts from ’shafts to spools to bearing kits to gear sets.
Revolution Gear & Axle
Well-known in rock-racing circles such as Ultra4, the axleshaft hardware available from Spidertrax comes in many different lengths (OE and custom) and stub shaft applications. For the Jeep market, the most notable Spidertrax products are its shafts for the standard Dana 60 often sought out as a bone-yard style upgrade by many hardcore Jeepers. The company’s axleshafts will also work for the new Dana Ultimate 60 axles designed specifically for the Jeep JK Wrangler. You can get the Spidertax Ultimate Axleshafts (pictured) for the GM 1-ton axles (kingpin axles with 1480 U-joints) with its “web-yoked” design that allows it up to 50 degrees of steering angle, and the billet (rather than forged) steel axles are available in domestic 4340 or military-grade 300M material. Spidertrax manufactures its products in-house with aerospace AMS heat-treating standards.
Summit can be a one-stop shopping source for enthusiasts, and it carries Motive Gear, and G2 axle products, as well as its own in-house Summit Racing Axle Upgrade Combo kit made up of various manufacturers’ parts. Among the 140 gear sets from Summit are ring and pinions available for Dana 30 (including Wrangler TJ- and JK-specific), Dana 35, and Dana 44 (pictured) axles (including Wrangler TJ- and JK-specific). G2 Axle & Gear model 60 Axle Assemblies are available from Summit as bolt-ins for ’84-’14 Jeep CJs and Wranglers. The G2 60 Axle Assemblies are available with Detroit Locker, ARB Air Locker, E-Locker, and Truetrac differentials, and some even come with disc brake assemblies. The G2 44 Axle Assembly is also available. The Summit Racing Axle Upgrade Combo includes 35-spline Yukon Gear front outer axles, Spicer U-joints, and your choice of Yukon Gear manual locking hubs or a Hardcore drive flange kit.
Yukon Gear & Axle
Offering a vast array of axle upgrade products, the Yukon Gear & Axle catalog of product includes lockers, limited-slip devices, axleshafts, ring-and-pinion gear sets, and master overhaul kits. Its Yukon Zip Locker (pictured) is an air-operated locker for on-demand traction, featuring a forged 8620 case and 4340 internal gears. The Yukon Grizzly Locker is automatic locking differential with an 8620 case, and the Grizzly is designed to reduce common locker failures due to shock loading or axleshaft breakage. Yukon Gear Kit packages contains front and rear ring-and-pinion sets and master overhaul kits. Each master overhaul kit contains Timken bearings and high-quality small parts and seals.
Yukon Gear & Axle