Yukon Gear High Performance Gear Set For Dana 44 JK Rear in a 4.88 Ratio
Fitting 37 inch tires to a Wrangler JK changes the effective gearing so much that the factory 3.21, 3.73 or 4.10 rear gears leave the engine bogging below its power band. The Yukon Gear & Axle YG D44JK-488RUB is a 4.88 ring and pinion for the rear Dana 44 used under 2007-2018 Jeep Wrangler JK and Wrangler Unlimited models, the deeper ratio JK builders reach for when they move past 35s or tow with oversized tires. It is a new set: 8.89 in. ring gear, 24-spline pinion, 10 ring gear bolts.
The pinion gear rides on the end of the rear driveshaft and drives the ring gear, which is bolted to the differential carrier and turns both rear axle shafts. With a 4.88 set the driveshaft spins 4.88 times for every turn of the tire. That multiplies torque at the wheels and brings engine speed at cruise back up to where it sat on stock tires, so the automatic stops hunting and the manual can pull its top gear again. Compared with 4.56, the 4.88 trades a little highway RPM for better crawl control and stronger pull with a heavy, built JK.
Yukon lists the ring gear as double drilled for both 7/16 in. and 1/2 in. ring gear bolts, which matters on the JK because carriers vary between trims and aftermarket lockers. Use the bolt size your carrier is threaded for, with fresh thread locker.
Check the axle tag and the ratio stamped on it, and confirm you have a Dana 44 rear. Almost every JK did, but Revolution Gear notes that fewer than a thousand early 2007 Wranglers left the factory with a Dana 35 rear instead. Then pick the ratio for the tire you actually run and how you drive; our gear ratio guide for bigger tires walks through the math. If the issue is a howl rather than lost power, drain the oil, look for metal and read the contact pattern first; our Dana 44 problems and rebuild cost guide covers what each noise usually means.
Yukon's fitment table covers the rear Dana 44 of the 2007-2018 Wrangler JK and Wrangler Unlimited: Rubicon, Sahara, Sport, Sport S, the 2007-2010 X and Unlimited X, and the 70th and 75th Anniversary models. Both Rubicon and non-Rubicon rear axles are listed, as are the 2007-2010 two-wheel-drive Unlimited Sahara and X and the 2010 two-wheel-drive Unlimited Sport. Despite the "RUB" in the part number, this is a rear-only set; it does not fit the JK front axle, a TJ Dana 44 or the 2018-up JL. Send us your year, trim and VIN if you are unsure, and browse more Dana 44 parts in our hard parts section. If 37s are not in your plans, the 4.56 JK rear set may suit you better.
| Brand | Yukon Gear & Axle |
| Part number | YG D44JK-488RUB |
| Fits | Yukon Gear High Performance Gear Set For Dana 44 JK Rear in a 4.88 Ratio |
| Type | Final Drive Gears |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
It is the most common pick for 37s, especially on the 3.6L automatic. Lighter-use rigs on 35s usually stay at 4.56, while heavy builds on 37s or larger sometimes go to 5.13.
Yes. Yukon lists it for both Rubicon and non-Rubicon JK rear Dana 44 axles from 2007 to 2018. Choose the bearing or overhaul kit that matches your trim.
A rear master bearing or overhaul kit, a matching 4.88 front set for the front axle, gear oil and a way to reprogram the tire size and axle ratio.
The JK rear carrier generally carries over between ratios, and Yukon drills this ring gear for both 7/16 in. and 1/2 in. bolts. Inspect the carrier bearings and side gears and reuse the bolt size your carrier is tapped for.
Drive gently with no towing for the first few hundred miles, let the axle cool if it gets hot, and change the gear oil after break-in to flush out wear metal.
