USA Standard Master Overhaul Kit For The Dana 44 JK Non-Rubicon Rear Diff

If you drive a Wrangler JK Sport, Sahara or another non-Rubicon trim and are about to re-gear for 35s, or the rear axle has started droning on the interstate, the bearings are the parts to replace. The USA Standard Gear ZK D44-JK-STD master overhaul kit is built for the non-Rubicon JK rear Dana 44. It gives you Koyo carrier and pinion bearings and races together with the pinion seal, shims and setup hardware, at a lower price than the Timken-based kits for the same axle.

What the overhaul kit does in a JK non-Rubicon Dana 44 rear

The JK rear is a Dana 44 with an 8.5 in. ring gear. On non-Rubicon models the carrier is the open differential or the optional limited-slip rather than the Rubicon's electric locker, and USA Standard lists a dedicated kit for this version. Inside, the pinion turns on a large inner and a smaller outer tapered bearing. A crush sleeve between them is compressed by the pinion nut to set preload. The carrier rides on two side bearings, and the shims behind them control backlash and carrier preload. Swapping ratios means setting all of this up from scratch, and running worn bearings after a re-gear is the fastest way to ruin a new gear set.

According to USA Standard Gear, the ZK D44-JK-STD includes carrier bearings and races, pinion bearings and races, the pinion seal, a complete shim kit, ring gear bolts, a pinion nut, a crush sleeve, thread locker, marking compound with a brush, and silicone for the cover. It does not include gears, a carrier or axle shaft bearings.

Symptoms on a non-Rubicon JK rear

• A drone or whine from behind the seats that builds with speed and is loudest at highway pace
• New or louder rear noise after a lift and larger tires were added on the factory ratio
• Chatter or clicking in slow, tight turns on a limited-slip carrier, often a sign of worn clutches and old fluid
• Clunking on take-off or when lifting off the throttle from loose pinion preload
• Oil slung onto the rear driveshaft or dripping from the pinion seal

How to check it before you buy

With the rear on stands and the driveshaft unbolted, turn the pinion flange slowly. A gritty or notchy feel is pinion bearing wear, and any in-and-out movement means preload is gone. Remove the cover, look for metal or milky water in the oil, and paint the ring gear to read the contact. Spin each rear tire too, because worn axle shaft bearings at the ends of the housing can sound like a center section problem. If the noise is at the wheel ends, the Yukon JK rear axle bearing and seal kit is the right fix and can be done in the same weekend.

Fitment

This kit is listed for the Dana 44 JK non-Rubicon rear, which covers the 2007-2018 Wrangler and Wrangler Unlimited in non-Rubicon trims. Two exceptions matter. A small number of early 2007 JKs, fewer than a thousand, were built with a Dana 35 rear, and this kit does not fit that axle. JK Rubicons use the locker carrier and need the JK Rubicon rear master overhaul kit. The JL and Gladiator use newer Dana 44 designs with different parts. Read the axle tag on the housing tube, or send us your year, trim and VIN. For the Timken-equipped version of this kit, see the Yukon YK D44-JK-STD kit, and find more kits in our rebuild kits collection.

Install notes

• Unbolt the brake lines or calipers as needed, pull the axle shafts, and keep the carrier bearing caps marked left and right
• Record the old pinion depth shim and carrier shim thicknesses before pressing anything off, then build your first setup from those numbers
• Press the races in square, then lubricate the new bearings with gear oil before checking rotating torque
• Bring the crush sleeve down gradually with the pinion nut; overshoot means replacing the sleeve, not backing the nut off
• Torque the new ring gear bolts with thread locker and confirm the pattern on drive and coast with the included compound
• Seal the cover with the supplied silicone, then fill with 75W-90 GL-5 gear oil unless your owner's manual lists otherwise, plus friction modifier for a limited-slip

Building traction at the same time? The Yukon Grizzly locker for the non-Rubicon JK Dana 44 is listed for this axle, and the overhaul kit supplies the new carrier bearings it needs.

Does the ZK D44-JK-STD fit a JK Rubicon rear?

No. The Rubicon rear uses the factory locker carrier and takes a Rubicon-specific kit. This one is for the non-Rubicon JK rear Dana 44 only.

Will it fit a 2018 JL Sport with a Dana 44 rear?

No. The JL rear Dana 44 is a newer design with different bearings. This kit is for the 2007-2018 JK non-Rubicon rear.

Is this all I need to re-gear my JK rear?

It covers the bearings, races, seal, shims and hardware. Add a ring and pinion in your new ratio, and have a dial indicator, inch-pound torque wrench and bearing puller or press available for setup.

Does it come with a cover gasket?

The JK rear cover seals with silicone, and the kit includes silicone for that job instead of a gasket.

What brand are the bearings?

USA Standard Gear lists Koyo bearings and races for this kit. If you prefer Timken, the Yukon YK D44-JK-STD covers the same axle.