Every project has an origin. A campfire conversation, a great idea glimpsed out on the trail, even a manufacturer's press release - all can form the nucleus for improvements and enhancements to our machinery. The initial seed for this modification foray came about when the local Jeep dealer brought a bare Jeep Rubicon housing out to the Chili Challenge event a couple of years ago in Las Cruces. A bare Dana 44 housing, brackets all in place, ready to bolt up to the front of any XJ/MJ/TJ for under $600 dollars? Hmmmm... the mental cogs started turning.
The faithful Jeep Comanche's (MJ) frontend was a candidate for strength upgrades and definitely needed some help in the traction department. Used primarily as a daily driver and as our long-range desert exploring/camping base vehicle, the truck does occasionally get pressed into service severe enough to test the longevity of the OEM frontend. While the Dana 30 itself is probably stronger than we typically give it credit, the wimpy little axle joints are a known failure waiting to happen. Later-model Dana 30s got the larger 5-760X-style joints, but our '88 far predated that enlightened design change. Our early frontend was also blessed with a two-piece, vacuum-actuated axle-disconnect system that had long ago been "trail-fixed" into a full-time system. We knew that the unitary bearings were well past their typical 100,000-mile life span and primed for replacement. If we could just slip a new Rubicon Dana 44 housing under the front of the Comanche, all these issues would be solved. At the offered price, the Rubicon solution was just too good to pass up.
All these thoughts took several weeks to slowly coalesce in my brain. By the time we were ready to do the deed, the event special pricing for the housing was in the rearview mirror. It took several tries and several dealers, but eventually a housing was sitting in the shop for a bit under the $600 figure. The price was right, but the housing sure looked bare. It was time for some stuffing! The availability of the Rubicon Dana 44 housing makes your project as potentially simple as picking your gear ratio, selecting almost any traction device you desire, sliding in a new set of inner axles, and reusing everything from the knuckles out from your existing Dana 30 housing. Of course, we weren't content with the quick and easy approach. If we were going to get greasy swapping the housing, we felt it only appropriate to make a few other changes.
The first step was to add some trail-grasping ability. We chose the new (at least to us) Eaton ELocker for the traction aid. The ELocker utilizes what has always seemed the ideal actuation device in the locker. The ELocker uses an electromagnet to drive a "ball ramp" mechanism. The activated electromagnet forces balls out of their pockets and up ramps. This, in turn, pushes locking pins into the back of the side gear, locking the axles together. Elecromagnetic action seems to be about as fail-safe and trouble-free an actuation system as can be had. We are anxious to try the ELocker out in the field and see if that is the reality over an extended period of time. For the inner axles, we chose to use a set of Superior Axle & Gear's Evolution Series 4340 alloy items.
In addition to far better metallurgical properties than stock axles, we have always been impressed by Superior's more "engineered" approach to building axles. Dual heat treatment (through-hardening and induction hardening), rolled splines, and Superior's exclusive Torque-Equalizing Diameter Profiles (sizing the axles so that the long and short side have equal "give") add up to an axle with a design and execution that is, well, superior. We really wanted to rid ourselves of the unibearing plague, so we sourced a Warn hub conversion kit. If we were going to go through the trouble of adding the stronger bearing/hub conversion, it made sense to us to get the additional muscle of utilizing the much stouter 5-on-5-1/2-inch pattern. See how one thing leads to another and a quick, simple project gets a little more involved? With the new bolt pattern on the front, we now needed new Superior axleshafts for the Dana 44 in the rear also (these shafts come drilled with both bolt patterns for indecisive types).
The new bolt pattern, of course, created the need for new wheels. To solve the clearance problems we had previously encountered with 15-inch rims and a high-steer arm kit, we went with Mickey Thompson Classic II alloy wheels in a 16x8 size. The 16-inch rims also open the door to additional tire sizes and choices. These were paired with a set of the new Mickey Thompson Baja Radial ATZ tires in the LT285/75/16 size (roughly equivalent to a 33x11.50x16). The whole affair ended up being a truly "bolt-on" upgrade, even with our enhancements. Our original concept of an easy and cost-effective way of upgrading the XJ/MJ/TJ front housing with a Rubicon 44 housing was realized. The Comanche now sports a stronger and more capable front axle assembly. Reliability has been greatly increased, and the new tire-and-wheel combination gives every early indication of being a big winner.