East Coast Gear Supply Bolt-In Dana 44 - An Ox Out BackPosted in How To: Transmission Drivetrain on October 6, 2014
When it comes to aftermarket axle upgrades, there is no shortage of rear axle options. Given that so many Jeep models were fitted with less-than-stellar axle assemblies from the factory (Dana 35 anyone?), the demand for a more durable axle is extremely high. Finding the right axle that fits your needs and budget can take some work.
We’ve been exploring the rear-axle options for our ’98 Jeep Grand Cherokee ZJ for some time. Since our ZJ was outfitted from the factory with the 5.2L V-8, it was gifted the bastard-child of the Dana 44 family, the Dana 44A. The A stands for aluminum, which is what the differential housing is comprised of. Not only is this axle extremely pricey to upgrade, but the aftermarket support is nearly non-existent. Oh, did we mention its C-clip? Yeah, it’s a real jewel.
For our Dana 44A replacement, we wanted an axle capable of handling V-8 power, remain stock width, have semi-float axle ends, and be capable of handling up to 35-inch-tall tires with ease. Something bolt-in would be even better. That last request took out a fair amount of contenders but uncovered a newly released axle.
While discussing our axle query with East Coast Gear Supply in Raleigh, North Carolina, owner Chase Perry recommended the company’s new ZJ Dana 44 rear. Offered for the ’84-’01 Cherokee XJ, ’87-’06 Wrangler, and ’93-’98 Grand Cherokee, the ECGS Dana 44 is designed to be a direct-fit bolt-in rear axle upgrade. Starting with an all-new Next Generation Dana 44 Rubicon differential housing, East Coast Gear Supply is able to offer the axle with the larger JK Dana 44 gearset, beefy 3⁄8-inch-thick axletubes, 1⁄4-inch-thick axle brackets, and Set 10 axle ends. We doubt our ZJ will ever see bigger than a 35-inch-tall tire, so the axle fit our build and budget nicely.
Since we use our ZJ as a daily driver, we opted for our rear axle to be equipped with an OX selectable locker. While OX is well known for its heavy-duty cable-actuated locker, we decided to install the pneumatic version (more on this later). Going with the heavy-duty version of the OX locker also allowed us to run massive 35-spline, 1.5-inch 4340 chromoly axleshafts. To get a firsthand look at how the rear axle comes together, we drug our ZJ to East Coast Gear Supply’s (ECGS) install shop and got the down low on the entire process.
The ECGS Dana 44 rear axle starts off with a Dana-sourced Rubicon-specific low-pinion Dana 44 differential housing. A set of 3-inch diameter, 3/8-inch-thick axletubes are then pressed and plug-welded to the housing.
The ECGS 44 is a semi-float housing, which uses a traditional four-bolt bearing retainer on each end. We opted for the Set 10 axle bearing ends, which allowed us to re-use our Jeep’s stock caliper brackets. Since the axle is intended as a stock-replacement assembly, the overall axle width is the same 60 1⁄2 inches.
Using a custom axle jig, 1⁄4-inch-thick axle brackets are MIG-welded on. ECGS knows that many of its customers have lifted Jeeps, so the company includes a higher offset track-bar mounting hole.
Dual-pattern (5-on-4.5 and 5-on-5.5) 4340 chromoly axleshafts are standard issue with the rear 44. The 1.5-inch, 35-spline ‘shafts are more in line with what you would see in the rear of an aftermarket Dana 60. It’s plenty overkill for the 33-inch tires we are currently running but should be more than adequate as our Jeep progresses to larger tires.
Mated to the 8.8-inch-tall Next Gen Dana 44 ring gear is a selectable OX locker. The OX is unique in that it can be actuated by air, cable, electric, or with an emergency trail-lock bolt. During normal driving conditions, the differential is completely open. When engaged, the locker acts as spool.
OX’s air-cylinder comes already integrated into the differential cover. The air actuator is connected to the internal shift-fork, which rides in the channel ring on the locker. When air is sent to the cylinder, the fork slides over and effectively “locks” the differential so both wheels will turn at the same speed.
ECGS outfits its axles with DOT-compliant hard and soft brake lines. Since the semi-float rear axle has Set 10 axle bearings, we were able to reuse our stock parking brake as well.
One additional upgrade we were pleased to have was in the brake department. The slotted rotors from EBC are designed to quickly expel braking gases, heat, and dust to increase braking performance. By upgrading to a slotted rotor without using a performance brake pad, it is sort of a waste. We got our hands on EBC’s Orange Stuff brake pads, which are designed for extreme racing and driving conditions. They’ll throw more brake dust, but the added stopping force on- and-off-road is worth the extra clean up.
With the air-cylinder for the OX already integrated into the cover, we only needed to thread in the included quick-disconnect air fitting. There is no adjustment needed.
Technically, you can run any air source you like for the OX, as long as it’s able to provide 85 pounds of pressure. We are using an OX-recommended Viair universal heavy-duty onboard air kit. The 33 percent duty cycle 400C compressor provides 150 psi at 2.54 cfm. The added bonus of the onboard air is that we now have a great source for pumping up our treads after a day in the dirt.
Using the OX air-solenoid option, we were able to keep the compressor contained in the rear of the ZJ. This greatly limited the amount of air line and wire that we had to plumb. We did need to extend a few wires to get the switches mounted to our center console, but the extra routing was worth it in the end.
Our ZJ is equipped with a BDS long-arm suspension, which reuses all of the factory suspension mounting points at the axle. While the axle was equipped to handle the stock ZJ sway bar, our new suspension would not allow it. Maybe the only downfall of this axle is that it is currently not ABS compatible. For us, this wasn’t a big deal. We simply pulled the bulb from the dash and called it a day. East Coast Gear Supply is looking into an ABS option, so be sure to contact them directly if you are interested.