Yukon Gear High Performance Gear Set For Dana 44 JK Rubicon in a 5.38 Ratio
A 5.38 ratio is about as deep as most people go in a Wrangler JK, and it is usually chosen for one reason: very large tires on a Jeep that still has to crawl slowly, climb and drive on the highway without the transmission living in its lowest gears. The Yukon Gear and Axle YG D44JK-538RUB is a high performance 5.38 ring and pinion for the Dana 44 rear axle used under the 2007-2018 JK. The ring gear is 8.89 inches in diameter, the pinion has 24 splines, and the ring gear is held by 10 bolts. Yukon lists it for the JK rear under both Rubicon and non-Rubicon trims.
The pinion gear is turned by the rear driveshaft and drives the ring gear on the differential carrier. At 5.38 the driveshaft turns 5.38 times per axle revolution, a large torque gain over the stock gearing that restores the effective ratio after a big tire swap and slows crawl speed off-road. The JK rear Dana 44 is its own design: Revolution Gear points out that the Dana 44s in the TJ, JK and JL are all different, so gears from one do not fit another. Yukon notes this set is double drilled for both 7/16 inch and 1/2 inch ring gear bolts, so it can bolt to either style of JK rear carrier. Yukon cuts the tooth surface finish to cut friction and heat, which matters at a ratio this deep.
Confirm the axle first. Almost every JK has a Dana 44 rear, but Revolution Gear reports that fewer than a thousand early 2007 JKs were built with a Dana 35 rear, and this set will not fit those. Then work out the ratio. The right number depends on tire diameter, engine and transmission, so compare 5.38 against the Yukon JK rear 5.13 set before ordering; 5.38 is mainly for the largest tires. If the job is driven by noise, drain the oil and check for metal before buying gears. Note that the front axle must be geared to the same 5.38 ratio.
Yukon's chart lists this set for the Dana 44 rear on 2007-2018 Jeep Wrangler JK 4WD models, including Rubicon, Unlimited Rubicon, Sahara, Unlimited Sahara, Sport, Sport S, X, Unlimited X and the 70th and 75th Anniversary editions, plus some 2WD Unlimited models. It is a rear-only set. The JK Rubicon front Dana 44 is reverse rotation and takes a different gear set, and non-Rubicon JKs have a Dana 30 front. Because most non-Rubicon JKs left the factory with a numerically lower ratio, check that your carrier or locker is built for the deeper ratio series before ordering, or send us your year, trim and VIN and we will confirm. Other axle gearing is listed on our hard parts page.
Install the gears with new bearings, races, a crush sleeve and a pinion seal. Yukon makes separate kits for each JK rear: the Yukon JK Rubicon rear master overhaul kit and the non-Rubicon JK rear master overhaul kit, so buy the one that matches your axle. Revolution Gear's setup chart lists the D44JK at a 0.042 in starting pinion depth, 22-35 in-lb pinion bearing preload, 0.006-0.010 in backlash, 80 ft-lb on the bearing caps, and 75 or 135 ft-lb on the ring gear bolts depending on bolt size. Use thread locker on the ring gear bolts and read the pattern with marking compound in both drive and coast. A deep ratio has a small pinion, so heat during break-in is the main risk: drive gently for the first few hundred miles, let it cool on long runs, avoid towing, and change the gear oil early. Use 75W-90 or 75W-140 gear oil, with friction modifier if the carrier is a clutch-type limited slip. Finish by programming the new tire size and axle ratio into the Jeep's computer.
| Brand | Yukon Gear & Axle |
| Part number | YG D44JK-538RUB |
| Fits | Yukon Gear High Performance Gear Set For Dana 44 JK Rubicon in a 5.38 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.
No. This is a rear Dana 44 set. The JK Rubicon front Dana 44 is a reverse rotation, short pinion axle with an 8.50 inch ring gear and needs its own front 5.38 set.
Yukon's fitment chart lists it for both Rubicon and non-Rubicon JK Dana 44 rear axles. The set is double drilled for 7/16 and 1/2 inch ring gear bolts. Confirm your carrier suits the deeper ratio, or send us your VIN.
5.38 is generally used with very large tires on a JK. The correct ratio depends on tire size, engine and transmission, so compare it with 5.13 and 4.88 before choosing.
A master overhaul kit or pinion install kit for your exact JK rear (Rubicon and non-Rubicon kits differ), gear oil, thread locker and marking compound. The front axle needs a matching 5.38 set.
Revolution Gear lists the JK Dana 44 at 0.042 in starting pinion depth, 22-35 in-lb pinion preload, .006-.010 in backlash, 80 ft-lb bearing caps and 75 or 135 ft-lb ring gear bolts by bolt size. Always confirm with the instructions in your install kit.
Drive gently for the first few hundred miles with no towing, let the axle cool on long highway runs, and change the gear oil early to remove break-in wear metal.
