Whether it’s a Cherokee or Wrangler, Dana 30 or Dana 44/30 hybrid, most Jeeps (other than fullsize) from the mid-’80s to the mid-2000s used the same basic solid-axle Dana 30 frontend with the same non-serviceable unit bearings. While these unit bearings do have the ease-of-installation advantage of bolting quickly onto the knuckle and handling both the load of the vehicle weight and the rotational force of the axleshaft, they can leave you stranded when they fail.
While the service life of a unit bearing should be much longer than a hub and spindle, servicing a unit bearing means getting a new one. The good news is that the use of unit bearings on solid front axles by the factory left an open door for aftermarket kits that convert axle ends to the older re-buildable locking hub design. Yukon Gear has a variety of Spin Free Locking Hub Conversion kits that come with all the parts needed for a major upgrade in strength and serviceability. In place of the unit bearing, the Dana 30 kit utilizes a spindle and wheel hub to handle the vehicle’s weight, and a new 27-spline 4340 chromoly stub shaft to transfer driving force to a locking hub directly attached to the wheel studs of the Dana 30 axle.
The Yukon kit costs about $1,300, so don’t try to fool yourself into thinking the fuel economy savings is going to make this kit pay for itself. And the “worn-out parts” justification isn’t going to work either because two new unit bearings, brake rotors, and U-joints can be had for les than a few hundred bucks. However, if you’re looking for a stronger setup that can be serviced on the trail and lessens the wear on your drivetrain, this kit becomes a good idea. Total installation time by our friend Frank Gilliland at South Bay Truck & 4x4 in Hawthorne, California, was about three hours. We weren’t rushing to finish, but Gilliland has extensive experience with these kits. Your own installation is likely to take around three to five hours in your driveway.
Performance-wise, there’s no driving difference if you’re not replacing a completely worn-out unit bearing and/or warped brake rotor. You should really never notice you made the switch except when filling up at the fuel pump or servicing (being able to) the wheel bearings. Not only does the kit increase overall frontend durability and serviceability, it adds strength by using stronger parts and separating out the duties of the outer axle ends. Instead of using a unit bearing to handle both loads, the spindle and wheel hub now deal with the force of the vehicle weight, and the locking hub takes the force of the rotating axleshaft to move the wheel and tire.
The Yukon Dana 30 Spin Free Conversion Kit with locking hubs installed looks and works pretty darn good on our Jeep XJ Cherokee. Total kit install time was about three hours.
With years to refine its product, we’d expect nothing less than a great kit with well-machined parts from Yukon Gear. The Yukon Dana 30 Spin Free Locking Hub Conversion Kit came complete (short of the tools and grease needed to install the U-joints) with outer 27-spline chromoly stub shafts, races, bearings, spindles, studs, wheel hubs, brake rotors, and 5x4.5 locking hubs.
We began by putting the brake rotors and hubs together with the wheel studs. A chewed-up pinion gear made a perfect driver to pound in the wheel studs and sandwich the brake rotors to the hubs. Make sure you fully seat all the studs. When you whack each one with a hammer, the resonance will be different when the stud is fully seated. A quick visual inspection will allow you to check for congruence by comparing how much each stud sticks out of the wheel hub.
The current unit bearings were not yet worn out, but this was the third pair in 110,000 miles on this Jeep. Not only is this a non-serviceable design, it requires the frontend to be moving 100 percent of the time that the vehicle is moving.
Once the hubs and rotors were together, our next step was to get out the inner axles (we’ll be reusing those) and pound out the U-joints that attach them to the outer axles (aka stub shafts). One minor downside to this conversion is that your front ABS will no longer function. The serviceable spindle-and-hub setup does not leave room to run the tone ring, and therefore your ABS brakes will cease to function (if they still did).
New 27-spline 4340 chromoly outer axleshafts are included in the Yukon hub conversion kit. New Spicer 5-760X U-joints are supplied to connect the new chromoly outer axles to your original inner axleshafts. In this Jeep’s case, they were upgraded 30-spline Dana 30 inner axles that fit into a 30-spline locking differential. A dust shield for each axle is also in the kit.
With the axle assemblies (driver-side shown) completed, they were slipped into the Dana 30 housing, and the inner axle splines were matched up in the differential.
New Yukon spindles attach to the knuckle instead of the unit bearing. These now take the load of the vehicle’s weight instead of the unit bearings.
Before bolting on the spindles over the axleshafts (driver side shown), make sure to install the seal and grease liberally. The spindles bolt onto the factory knuckles with three bolts, just like a unit bearing would.
Two races are supplied for each wheel hub. The bearing with the larger inner diameter goes on the inside of the hub (closest to the knuckle). Make sure you choose the proper race before driving it into the wheel hub.
With the correct races and bearings installed on each side of the wheel hub, the hub and rotor can be slipped onto the spindle.
Two spindle nuts and one alignment spacer are used to retain the wheel hub on each spindle. Once the setup is tight, the axleshafts (driver side shown) are kept from sliding out using a spacer and a C-clip.
Twenty-seven–spline locking hubs are provided to slip over the hub-and-spindle assembly. It sort of feels funny to have the final part of the conversion kit simply slip on and be held tight by the same wheel studs that hold the wheel and tire on. That being said, we can’t think of any strength disadvantage it gives to this kit.
Opt for 5x5.5
The standard Yukon Gear Dana 30 locking hub conversion kit stays with the factory 5x4.5 wheel-lug pattern and uses a 27-spline outer axle. If you want even more strength and to step up to a 1/2-ton lug pattern, Yukon Gear offers a Dana 30 locking hub kit with larger Yukon locking hubs, a 5x5.5 lug pattern, and 30-spline stub shafts. It’s an upgrade in every way, but remember that you’ll need to swap out wheels and match that 5x5.5 pattern with the rear axle too.