Revolution Gear & Axle 07-18 Jeep Wrangler JK Rubicon Dana 44 Front 4.56 Ratio Ring &...

A 2007-2018 Jeep Wrangler JK Rubicon on 35 inch tires with the factory gears feels slow, hunts between gears on the highway and struggles on grades. Going to 4.56 front and rear is the most common fix for that combination, and this Revolution Gear and Axle D44RS-456RUB is the front half of the job: a 4.56 ring and pinion cut for the reverse-rotation Dana 44 under the front of the JK Rubicon.

What the ring and pinion does in the JK Rubicon front Dana 44

The front axle on a JK Rubicon is a high-pinion design. The pinion enters the housing above the axle centerline, which keeps the front driveshaft higher and away from rocks, but it means a conventional gear would be driven on its weaker coast side when the Jeep moves forward. Gears for this axle are cut in reverse rotation so the strong drive side of the teeth carries the load. Revolution's product page lists the set as reverse rotation, 8620 steel, a 24-spline pinion, an 8.5 inch ring gear and ten ring gear bolt holes drilled for both 7/16 and 1/2 inch bolts. At 4.56 the driveshaft turns 4.56 times per tire revolution, which puts engine rpm back where the transmission wants it after a big tire upgrade.

Symptoms and reasons to regear the front

• Poor acceleration and frequent downshifts after moving to 35 inch or larger tires
• Speedometer reading low and fuel economy falling after the tire change
• Whine from the front axle in 4WD or under load that was not there before
• Chipped teeth on the front ring gear after hard rock crawling with the locker engaged
• A rear axle already regeared to 4.56 that needs a matching front before 4WD use

How to confirm before buying

Confirm the Jeep is a Rubicon. Non-Rubicon JKs use a Dana 30 front, which needs different gears. Check the axle tag or the build sheet for the current ratio, and confirm the front is still the factory Dana 44 with the reverse-cut pinion. Front and rear ratios must match exactly or the drivetrain will bind in 4WD, so plan to order the rear at the same time, such as the Revolution JK Dana 44 rear 4.56 set. Our JK regear kit buyer's guide explains how to choose a ratio for your tire size, and the Dana 44 problems guide covers what else wears in this axle.

Fitment

The listing and Revolution's page fit this set to the front Dana 44 reverse-rotation axle on the 2007-2018 Jeep Wrangler JK Rubicon, two-door and Unlimited. It does not fit the JK Dana 30 front, the JL or Gladiator front axle, or a standard-rotation Dana 44. Dana 44 carriers are split by ratio, and Revolution lists its 3.73 version of this set on the 3.73-and-down carrier, so a 4.56 belongs on the 3.92-and-up carrier. Check what carrier your axle has before ordering, especially if the factory locker carrier has been replaced. If in doubt, send us the year and VIN and we will confirm it. For bigger tires, the JK Rubicon front 4.88 set is the next step deeper.

Install notes

Gears alone are not enough. Use the Revolution JK Rubicon front master install kit or the USA Standard JK Rubicon front overhaul kit for new bearings, shims, seal and crush sleeve. Revolution's setup chart gives these starting points for the D44JK: 0.042 in starting pinion depth, 22-35 in-lb pinion bearing preload, 0.006-0.010 in backlash, ring gear bolts at 75 ft-lb for 7/16 inch or 135 ft-lb for 1/2 inch hardware, and 80 ft-lb on the bearing caps. Unplug the locker connector and pull the axle shafts before spreading the housing slightly to remove the carrier. Reverse-cut gears read the pattern differently, so check both drive and coast sides with marking compound. Fill with 75W-90 or 75W-140 gear oil, update the ratio and tire size in the computer, and keep the first few hundred miles easy before changing the oil.

Does this fit a non-Rubicon JK Wrangler?

No. Non-Rubicon JKs have a Dana 30 front axle. This set is cut for the reverse-rotation Dana 44 front used on the 2007-2018 JK Rubicon.

Do I have to change the rear gears too?

Yes. Front and rear ratios must match. Running 4.56 in front with a different rear ratio will bind the drivetrain in 4WD and can damage the transfer case.

What tire size is 4.56 meant for?

4.56 is a common choice for a JK Rubicon on 35 inch tires, especially with an automatic or a heavier build. Larger tires around 37 inches often call for 4.88 or deeper.

Can I keep the factory locker?

A 4.56 set goes on the 3.92-and-up Dana 44 carrier. Confirm your front locker carrier is on that side of the split before ordering, and reuse it with new carrier bearings and shims.

Do I need to reprogram the Jeep after the regear?

Yes. Update the axle ratio and tire size with a programmer or dealer tool so the speedometer, shift points and stability control read correctly.