Revolution Gear & Axle 07-18 Jeep Wrangler JK Dana 44 Chromoly Discovery Series Front Axle Kit

The Revolution Gear & Axle DC-D44-JK is a 4340 chromoly front axle shaft kit for the 2007-2018 Jeep Wrangler JK Rubicon and its factory Dana 44 front axle. It is the upgrade JK Rubicon owners look for after snapping an outer stub or a U-joint ear on the trail, or before that happens, when 35 in. or larger tires, lower gears and the factory front locker start putting more torque through the front shafts than the stock steel was built for.

What the axle shafts do in a JK Rubicon Dana 44

Each side of the solid front axle uses two shafts joined by a U-joint inside the steering knuckle. The inner shaft splines into the differential carrier and runs the length of the axle tube; the outer stub passes through the unit bearing and drives the hub. The U-joint lets the outer stub turn with the steering. When the Rubicon's front locker is engaged, both front shafts are tied together, so a tire that hooks a rock can load one side with nearly everything the engine and transfer case can send. That is why the outer stub at the U-joint ear and the joint itself are the usual failure points. This kit replaces both inners and both outer stubs with 4340 chromoly shafts, 30-spline at the carrier, and includes two Dana Spicer 5-7166X 1350-style U-joints and eight full-circle snap rings to assemble them. Chromoly is tougher than stock carbon steel and tends to twist before it snaps, so a hard hit is more likely to leave you a damaged shaft that still drives than a broken one.

Symptoms that call for front axle shafts

• A loud bang off-road followed by no drive to one front wheel with the locker engaged: a broken outer stub, inner shaft or U-joint.
• Clicking or popping from one front corner while turning in 4WD, typical of a worn or failing axle U-joint.
• A cracked or bent U-joint ear, or a joint with visible play when you rock the outer stub by hand.
• Gear oil seeping out at the knuckle, which usually means a worn inner axle tube seal and is a good reason to pull the shafts anyway.
• Planning a move to 35s or 37s with low gears and regular locker use on a stock-shaft front.

How to confirm before buying

Lift the front tire off the ground, put the transfer case in neutral, and turn the wheel by hand while watching the U-joint through the knuckle. Grab the outer stub and check for slop in the joint. If one wheel freewheels while the other drives, the shaft or joint on that side has failed. Our Dana 44 problems and rebuild cost guide covers the common JK front failures, and chromoly axle shafts vs. stock explains when the upgrade earns its price.

Fitment

Revolution Gear lists the DC-D44-JK for the 2007-2018 Wrangler JK Rubicon with the factory Dana 44 front axle and 30-spline axles, 2-door and Unlimited. It is not for the Sport and Sahara models, which use a Dana 30 front; those need the JK Dana 30 chromoly front axle kit. The manufacturer also states this kit is only compatible with the factory locker, so if you have already installed an aftermarket front locker, send us the locker part number before ordering. Check the axle tag on the differential cover, or send your year and VIN and we will confirm. See our Dana 30 vs. Dana 44 front axle comparison if you are not sure which axle you have, and browse more rebuild kits for the JK.

Install notes

• The shafts ship unassembled. Press the 5-7166X joints into the inner and outer shafts and lock them with the full-circle snap rings before installation; snap ring pliers and a U-joint press make this simple.
• Remove the wheel, brake caliper and rotor, unplug the ABS sensor, then unbolt the unit bearing from the back of the knuckle and slide the old assembly out.
• Axle seals are not included. Replace the inner tube seals while the shafts are out using a proper driver such as the Dana 44 front axle seal installer or the Dana 30/44/60 inner axle seal installer tool.
• Guide the inner spline into the carrier gently so it does not drag across and tear the new seal, then torque the unit bearing bolts to factory spec and top off the front differential with gear oil.
• Regearing at the same time? A Rubicon on bigger tires usually needs matching front and rear gears; the Yukon 4.88 gear set for the JK Rubicon rear Dana 44 is one half of that job, and our JK regear kit buyer's guide covers the rest.

Will this kit fit my 2015 Wrangler Unlimited Sahara?

No. Sport and Sahara JK models use a Dana 30 front axle with 27-spline shafts. This kit is for the Rubicon's Dana 44 front with 30-spline shafts. The Sahara needs the JK Dana 30 chromoly kit.

Does it work with an aftermarket front locker?

Revolution Gear states the kit is only compatible with the factory locker. If you have swapped in an aftermarket locker, send us its part number before you order so we can check the spline and shaft engagement.

Are the U-joints included?

Yes. The kit includes two Dana Spicer 5-7166X 1350-style U-joints and eight full-circle snap rings, along with two inner shafts and two outer stubs. The shafts arrive unassembled.

Are axle seals included?

No. Buy new inner axle tube seals and replace them while the shafts are out. A worn seal lets gear oil run into the knuckle and unit bearing.

What warranty comes with it?

The manufacturer covers the axle shafts for 10 years against defects, breakage, bends and twisted splines, and the Spicer U-joints for one year against manufacturing defects. Bearings and seals are wear items and are not covered.