Yukon Gear Master Overhaul Kit For Dana 44 Standard Rotation Front Diff w/ 30 Spline

A front Dana 44 that whines with the hubs locked, rumbles at highway speed in four-wheel drive, or has gear oil seeping past the pinion seal or the inner axle seals is telling you the bearings and seals have had enough. Yukon's YK D44 is the master overhaul kit for the standard rotation Dana 44 front differential that uses 30-spline inner axle shafts, the low-pinion front axle found under many classic 4x4 trucks and SUVs. It puts every bearing, race, seal and shim for the center section in one box.

What the master overhaul kit does in a front Dana 44

In a standard rotation front Dana 44, the pinion enters the housing below the carrier centerline, the same gear cut as a rear axle. The pinion turns on two tapered bearings with its depth set by a shim under the inner race, and the carrier with its 8.5 inch ring gear turns on two side bearings with shims that set preload and backlash. The axle shafts slide into the side gears on 30 splines and pass inner axle seals on their way out to the knuckles. Per the kit listing, Yukon includes Timken carrier bearings and races, Timken pinion bearings and races, a pinion seal, axle seals, a complete shim kit, ring gear bolts, a pinion nut, oil baffles and slingers, thread locker, marking compound with a brush and a cover gasket.

Symptoms that point to this kit

• Whine from the front end in 4WD that goes away when the hubs are unlocked
• Howl that changes pitch between throttle and coast, a sign the pinion bearings have lost preload
• Growl that rises with road speed from worn carrier bearings
• Gear oil on the front driveshaft or yoke from a leaking pinion seal
• Low front diff fluid with wet knuckles or tube ends from tired inner axle seals
• Bearing fragments or heavy glitter on the fill plug

How to confirm before you buy

First make sure the noise is the differential. Drive the same road with the hubs unlocked and the transfer case in 2WD; if a whine disappears, it lived in the front axle or front driveshaft. Then raise the front, pull the cover and drain the oil into a clean pan. Rock the pinion yoke up and down and in and out; any free play means the pinion bearing preload is gone. Spin the carrier by hand and feel for roughness, and paint the ring gear to read the pattern. Note the old backlash with a dial indicator before anything comes apart. Chipped or pitted ring gear teeth mean you should order gears now, such as the Yukon Dana 44 standard rotation 4.88 gear set, because the setup labor is the same.

Fitment

This kit fits Dana Spicer 44 front axles that are standard rotation and use 30-spline inner shafts. Three checks keep you out of the wrong box. Rotation: if the pinion sits low, below the axle centerline, it is standard rotation; a high-pinion front Dana 44, including the JK and JL Wrangler fronts, uses reverse-cut gears and a different kit. Splines: pull an inner shaft and count, because older front Dana 44s also came with 19-spline shafts, which take the YK D44-19 kit. Axle type: TJ Rubicon axles, Ford TTB independent fronts and center-disconnect fronts each have their own kits. Read the Dana tag on the axle tube or send us your year, VIN and tag numbers and we will confirm it. Other axle kits are on the rebuild kits page.

Install notes

• Mark the carrier bearing caps left and right; they are machined with the housing and only fit one way.
• Pull the old side bearings with a clamshell carrier bearing puller so the original shims survive for measuring.
• Set pinion depth first, then pinion preload, then carrier preload and backlash, and check the pattern with the included marking compound.
• Apply thread locker to clean, dry ring gear bolts and torque them to the factory figure in a star pattern.
• Fill with 75W-90 gear oil, or 75W-140 if the axle sees heavy towing; add friction modifier only for a clutch-type limited slip. A Trac Loc clutch kit is the time to refresh a worn Dana Trac Loc carrier.

How do I know if my front Dana 44 is standard rotation?

Look at where the driveshaft enters the differential. A pinion below the axle centerline is standard rotation. A high-pinion front Dana 44, such as the JK and JL Wrangler front, is reverse rotation and needs a different kit.

What is included in the YK D44 kit?

Timken carrier and pinion bearings and races, a pinion seal, axle seals, a complete shim kit, ring gear bolts, a pinion nut, oil baffles and slingers, thread locker, marking compound with brush and a cover gasket.

My front axle shafts are 19-spline. Will this kit work?

No. This kit is for 30-spline front Dana 44s. A 19-spline Dana 44 takes the Yukon YK D44-19 master overhaul kit.

Should I replace the ring and pinion at the same time?

Only if the teeth are chipped, pitted or worn, or you want a ratio change. The labor to set up bearings and shims is the same either way, so it is the cheapest time to do it.

What gear oil does a rebuilt front Dana 44 take?

Use 75W-90 gear oil, or 75W-140 for heavy towing. Add friction modifier only if the axle has a clutch-type limited slip.

Is this kit easy to install at home?

It is a full gear setup job that needs a bearing puller, a press, a dial indicator and an inch-pound torque wrench for preload. If you have not set up gears before, have an axle shop install it.