Yukon Gear Steel Spool For Dana 44 w/ 30 Spline Axles / 3.92+

If you keep breaking spider gears in a Dana 44, or you are building a dedicated rock crawler, mud truck or drag car and want both tires turning at all times, a spool is the simplest answer. Yukon Gear and Axle part YP FSD44-4-30UP is a steel spool for the Dana 44 with 30 spline axle shafts, made for ring and pinion ratios of 3.92 and numerically higher. Yukon's application list covers vintage Jeep CJ, Wagoneer and J-trucks, 1986-1993 Cherokee and 1997-2006 Wrangler rear axles, early Bronco and Ford F-series, Chevy and GMC K-series, International Scout and Dodge W-series and Ramcharger axles. Yukon states plainly that it is not recommended for street-driven vehicles.

What a spool does in a Dana 44

A normal Dana 44 carrier holds spider gears and side gears so the outside wheel can turn faster than the inside wheel in a corner. A spool deletes all of that. It is a single machined steel piece: the ring gear bolts to its flange, carrier bearings press onto its hubs, and both 30 spline axle shafts slide straight into it. With nothing inside to slip or break, both wheels get 100 percent of the available traction all the time. That is exactly why it works off-road and at the track, and exactly why it fights you on pavement: in every turn one tire has to scrub, the vehicle pushes wide, tires wear faster, and on slick roads the back end can step out.

Signs your build needs a spool (or does not)

• Repeated broken spider gears, cross shafts or side gears in an open or limited slip Dana 44.
• A clutch-type limited slip that chatters, or no longer locks, on a trail or race vehicle.
• A vehicle that is trailered to the trail or the strip rather than driven daily.
• If the truck is a daily driver, a selectable or automatic locker is usually the better choice. A spool in a front axle also makes steering heavy whenever the hubs are locked.

How to confirm it fits before you buy

Three things have to be true. First, the axle must be a Dana 44, not a Dana 35 or Chrysler 8.25, which many Jeeps of the same years came with. Second, the axle shafts must be 30 spline; count the splines on a pulled shaft. Third, the gear ratio must be 3.92 or numerically higher. The Dana 44 uses two carrier sizes: one for roughly 2.72 to 3.73 ratios and one for 3.92 and up, because the deeper gears put the ring gear in a different position. If you are at 3.73 or lower, this spool will not work; that ratio range takes a different part such as the Yukon open Dana 44 carrier for 3.73 and down. The 32 spline axles in JL and JT Rubicon models and the 8.9 inch ring gear JK axles are not on Yukon's list.

Fitment

Yukon's fitment chart for this part lists Dana 44 rear axles in 1997-2006 Jeep Wrangler, 1986-1993 Cherokee, 1986-1992 Comanche, CJ5, CJ6, CJ7 and Scrambler, Wagoneer, Grand Wagoneer and J10, plus rear axles in some 1960s-70s Chevy, GMC and Ford trucks and vans and the 1984-85 and 1992-94 Camaro. Front Dana 44 applications on the chart include 1971-1979 Ford Bronco, 1966-1979 F-100, F-150 and F-250 4x4s, Chevy and GMC K10, K20, K5 Blazer and Suburban through 1980, Dodge W-series and Ramcharger, 1994-2002 Ram 2500 4WD and International Scout. The 1978-1979 Bronco and F-series front entries are reverse rotation axles. Because these axles changed shaft spline counts and ratios many times, match the spline count and ratio on your own axle, or send us the year, model and VIN. Browse more axle parts in our hard parts catalog.

Install notes

• Treat it like any carrier change: the spool takes carrier bearings and shims, so plan on new carrier bearings, then set preload, backlash and the contact pattern from scratch. The listing does not show bearings included.
• Use clean threads and threadlocker on the ring gear bolts and torque them to the axle maker's spec.
• If you are regearing at the same time, the Yukon Dana 30 front and Dana 44 rear 4.88 gear and install kit for the TJ Wrangler puts a TJ in the ratio range this spool requires.
• Fill with straight 75W-90 or 75W-140 gear oil. There are no clutches, so no friction modifier is needed.
• On a front axle with ball joints and spindles that are already worn, the extra load of a locked front end finds them fast; inspect them and parts like the Yukon Dana 44 and GM 8.5 front spindle before trail use.
• Expect tire chirp in tight turns and plan rotations more often.

Will this spool work with 3.73 gears in my Dana 44?

No. Yukon lists it for 3.92 ratio and up only. The Dana 44 uses a different carrier size for 3.73 and lower ratios, so a 3.73 or numerically lower gear set needs the low-ratio carrier or spool.

Does it fit a JL Wrangler or JT Gladiator Rubicon Dana 44?

No. Those axles use 32 spline shafts, and this spool is for 30 spline axles. It is also not on Yukon's list for the JK Dana 44 with the 8.9 inch ring gear.

Can I drive a spooled Jeep on the street?

Yukon says it is not recommended for street-driven vehicles. It will work, but expect tire scrub and chirp in turns, faster tire wear, and the vehicle pushing wide or sliding on wet or icy roads.

Do I need special gear oil?

No friction modifier is needed because a spool has no clutches. Use a quality 75W-90 or 75W-140 gear oil and fill to the bottom of the fill hole.

Do I have to reset the gears when I install it?

Yes. Any time the carrier is replaced the backlash, carrier bearing preload and contact pattern must be set again, usually with new carrier bearings.