Yukon Gear High Performance Gear Set For Dana 44 JK Rear in a 4.88 Ratio

Yukon Gear YG D44JK-488RUB Dana 44 JK Rear Ring and Pinion Gear Set in 4.88 Ratio

Jeep Wrangler JK owners running 35 to 40 inch tires who need aggressive torque multiplication will find the YG D44JK-488RUB from Yukon Gear purpose-built for their application. The YG D44JK-488RUB is a high-performance ring and pinion gear set designed specifically for the Dana 44 rear differential found in 2007 through 2018 Jeep Wrangler JK models including Rubicon, Sahara, Sport, Unlimited, and X trims. Yukon Gear engineers produce the YG D44JK-488RUB from premium 8620 alloy steel with advanced heat treating and precision reverse-cut gear geometry, delivering low-end pulling power for rock crawling, trail riding, and daily street driving on oversized tires. The YG D44JK-488RUB is compatible with factory and aftermarket locker carriers for the JK Dana 44 platform.

Features and Benefits

• Premium 8620 alloy steel with advanced heat treating for superior strength under extreme off-road loads
• 4.88 ratio engineered to restore throttle response and drivability with 35 to 40 inch tires on the Wrangler JK
• Precision reverse-cut gear tooth profile for the Dana 44 JK rear application
• Designed to OEM tolerances for exact fitment in Jeep Wrangler JK Dana 44 rear differential
• Compatible with Yukon Grizzly locker, DuraGrip limited slip, and other aftermarket carriers
• 24-spline pinion shaft as specified for the Dana 44 JK rear axle
• Backed by Yukon Gear Y.E.S. extended service protection plan option
• Covers all 2007 to 2018 JK trims including Rubicon, Sahara, Sport, Unlimited, and X

Vehicle Fitment

Product Specifications

What Is Included

• One ring gear
• One pinion gear
• Installation instruction sheet

Frequently Asked Questions

What Jeep models does YG D44JK-488RUB fit?
This gear set fits the Dana 44 rear differential in all 2007 through 2018 Jeep Wrangler JK models, including Rubicon, Sahara, Sport, Sport S, Unlimited, X, and special edition trims.

Is 4.88 the right gear ratio for large tires on a JK?
A 4.88 ratio is well suited for Jeep JK builds running 37 to 40 inch tires. It recovers the low-end torque and highway rpm that are lost when large tires are installed over the factory gear ratio.

Do I need a master install kit with YG D44JK-488RUB?
Yes. A Dana 44 master installation kit including new pinion and carrier bearings, seals, shims, and a crush sleeve or solid spacer is required for correct backlash and preload during installation.

Does the Magnuson-Moss Warranty Act protect my Jeep factory warranty?
Under the Magnuson-Moss Warranty Act, a dealership cannot void your vehicle warranty simply because an aftermarket part was installed. The dealer must demonstrate that the aftermarket part directly caused the specific failure being claimed.

How does the Dana 44 JK rear differ from the standard Dana 44?
The Dana 44 JK rear uses a reverse-cut ring gear with a 24-spline pinion shaft, so it requires gear sets specifically engineered for the JK application such as the YG D44JK-488RUB. Standard Dana 44 gear sets are not interchangeable.

Can YG D44JK-488RUB be used with an ARB, Eaton, or Yukon locker?
Yes. The ring and pinion gear set is compatible with most aftermarket locker and limited-slip carriers designed for the Dana 44 JK rear, including ARB Air Locker, Eaton Detroit Locker, Yukon Grizzly, and Yukon DuraGrip.

Should I regear the front and rear axles at the same time?
Yes. When regearing a Jeep JK, matching the front and rear ratios is essential for proper 4WD operation and transfer case engagement. Front and rear gears must share the same ratio.

What gear oil should I use after installing YG D44JK-488RUB?
Use 75W-140 full synthetic gear oil in the Dana 44 JK rear differential. If an air locker is installed, confirm the locker manufacturer fluid specification before filling.

Installation Instructions

1. Drain differential fluid and remove axle shafts and the differential cover.
2. Mark bearing caps with a punch, then remove the carrier assembly from the housing.
3. Press off the old ring gear and clean the carrier flange mating surface.
4. Install the new ring gear from YG D44JK-488RUB and torque all bolts in a star pattern to specification.
5. Remove the old pinion, bearings, and crush sleeve from the differential housing.
6. Press new pinion bearings into the housing and onto the pinion shaft.
7. Set pinion depth using shims and a dial indicator setup per the Yukon instruction sheet.
8. Achieve proper pinion bearing preload with an inch-pound torque wrench and a new crush sleeve.
9. Reinstall the carrier with side bearing shims adjusted for correct backlash.
10. Verify gear contact pattern using gear marking compound and adjust depth and backlash as needed.
11. Reinstall the differential cover using a new gasket or RTV and fill with 75W-140 synthetic gear oil.
12. Break in gears gradually over 500 miles and perform a fluid change at the end of the break-in period.

Prop 65 Warning: This product can expose you to chemicals including lead, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information, go to www.P65Warnings.ca.gov.