Yukon Gear Replacement Crush Sleeve Eliminator For JK Dana 44 Rear

Regearing the rear of a Jeep Wrangler JK, or chasing a rear pinion that keeps whining and leaking after a gear swap? The factory Dana 44 rear in the JK sets pinion bearing preload with a collapsible crush sleeve, and a sleeve that was under-crushed or over-tightened is a common reason a fresh setup goes noisy. Yukon Gear & Axle SK CSJK-R swaps that sleeve for a solid spacer and a shim pack, so preload is set by measured shim thickness and holds where you put it.

What the solid spacer does in a JK Dana 44 rear

The pinion in the JK rear axle rides on an inner and an outer tapered roller bearing. Whatever sits between those two bearing cones decides how hard the nut clamps them together, and that clamp load is pinion bearing preload. A crush sleeve gets there by deforming: Yukon's installation manual says a sleeve collapses at roughly 300 to 400 ft-lb on the pinion nut, and once preload goes past target the only way back is a new sleeve. On a rear axle that sees tire-spin shock and heavy throttle, a marginal sleeve can also settle and let the pinion walk.

With this kit the solid spacer takes the nut load and cannot crush. You torque the nut fully, read rotating drag, and if it is off you pull the yoke and change the shim stack. Yukon's updated setup chart lists the JK Dana 44 front or rear with these numbers:

• Pinion bearing preload: 20-30 in-lb with new bearings, 10-15 in-lb with used bearings
• Backlash: 0.006-0.011 in on a 5-cut gear set, 0.005-0.008 in on a 2-cut set
• Starting OEM pinion depth shim reference: 0.042 in
• Bearing cap torque: 80 ft-lb

Symptoms of lost rear pinion preload

• A rear axle whine that shows up after a regear and gets louder over the next few hundred miles
• Clunk on and off the throttle or when shifting from drive to reverse
• In-and-out play at the rear pinion yoke with the driveshaft off
• A pinion seal that leaks again soon after replacement
• A gear contact pattern that has moved toward the toe or heel since setup

Our crush sleeve vs solid spacer guide explains when the conversion is worth it, and the pinion seal leak guide covers seal-only fixes.

How to confirm before you buy

Unbolt the rear driveshaft at the yoke and push and pull on the yoke. Any end play means preload is gone and the pinion bearings should be inspected or replaced while you install the spacer. Drain the gear oil and look for flakes. If the noise is hard to place, the transmission vs differential noise guide helps rule out other sources first. For gear setup details, see our backlash and pinion depth guide.

Fitment

• Yukon part number SK CSJK-R, rear axle only
• 2007-2017 Jeep Wrangler JK 4WD with the Dana 44 rear, Rubicon and non-Rubicon
• 2007-2010 Jeep Wrangler JK 2WD with the non-Rubicon Dana 44 rear
• Yukon's chart also lists Nissan M226 rears in the 2003-2015 Frontier, Pathfinder, Titan and Xterra

Yukon's fitment chart stops at 2017, so 2018 JK owners should confirm the axle before ordering. This kit is not for the JK front axle, which uses SK CSJK-F, or for JL axles. Read the tag on the cover bolt or send us your year and VIN if you are unsure. More axle parts are in our hard parts section.

Install notes

• Mark the driveshaft and yoke so they go back in phase, then remove the pinion nut and yoke
• Remove the carrier, drive out the pinion, and discard the old crush sleeve
• Fit the solid spacer and a starting shim stack, install the outer bearing, a new pinion seal, the yoke and the nut
• Torque the nut and check drag with an inch-pound torque wrench; more shim lowers preload, less shim raises it
• Seat the bearings with a light tap on each end of the pinion and recheck before setting the carrier back in
• Refill with the gear oil grade in your owner's manual, plus friction modifier if the axle has a clutch-type limited slip

The kit does not include bearings or a seal. If they are coming out, the JK Rubicon rear pinion install kit or the non-Rubicon rear pinion install kit supplies them, and the Yukon JK rear pinion seal is sold on its own.

Does SK CSJK-R fit both Rubicon and non-Rubicon JK rear axles?

Yes. Yukon lists it for the 2007-2017 Wrangler JK Dana 44 rear on both Rubicon and non-Rubicon 4WD models, and for 2007-2010 2WD JKs with the non-Rubicon rear.

Will this fit the front axle on my JK?

No. This is the rear kit. The JK front Dana 30 and Rubicon Dana 44 front use Yukon SK CSJK-F.

Are pinion bearings and a seal included?

No. The kit is the solid spacer and preload shims. Use a pinion install kit or a master overhaul kit if your bearings need replacing, and fit a new pinion seal.

What preload should I set with new bearings?

Yukon's setup chart lists 20-30 in-lb of rotating torque for the JK Dana 44 with new bearings and 10-15 in-lb with used bearings.

Can I reuse the solid spacer if I take the pinion apart again?

Yes. Unlike a crush sleeve, the solid spacer does not deform, so it can be reused and preload can be reset by changing shims.