Building an extreme Jeep typically requires the use of very heavy-duty axle assemblies. These axles usually tack on a significant amount of weight to your project. Interestingly, the most notable advantages of a flatfender Jeep are its small size and light weight. Tossing 1,000 pounds of axles under it sort of defeats the purpose of building a tiny and nimble 4x4. The Dana 44 axle is a great choice for axle swappers looking for a balance of durability and light weight. Versions of the traditional Dana 44 axles have been offered in in front and rear applications in all brands of domestic 4x4s for over 60 years. Dana 44 abundance, adaptability, and aftermarket support is unrivaled in the axle industry. You can pretty much roll into any wrecking yard in America and find plenty of Dana 44 axle assemblies in one form or another, so that’s sort of what we did.
Our GPW should weigh in at around 3,000-3,500 pounds once completed. Since we’re only running 33-inch tires, a Dana 44 is almost overkill. We started by getting our hands on a ’69-’73 Jeep Wagoneer Dana 44 rear axle. It was actually half bolted-in under an FSJ rotting on our buddy’s desert property. It features 30-spline semi-floating flanged axleshafts with a 5-on-5.5 lug pattern. It’s about 60 inches wide, and the differential is offset to the passenger side, so it matches the offset output of our Spicer 18 transfer case. Next, we set out to find a ’74-’79 Jeep Wagoneer front axle. This Dana 44 is also about 60 inches wide with 30-spline axleshafts. Like our rear axle, the differential is offset to the passenger side as well. However, it has a 6-lug wheel bolt pattern. The good news is this can be converted to a 5-on-5.5 lug pattern by bolting on the correct combination of brake and spindle components—no machining necessary. With our axles selected and acquired, we went to work tearing into them with help from Off Road Evolution in Fullerton, California.
Step By Step
We stripped down our Dana 44 axles, loaded them up, and headed on down to Off Road Evolution to have the EVO tech crew regear them for us. Off Road Evolution uses a case spreader to ease Dana gear installation and ensure proper carrier bearing preload for long gear and bearing life.
The old shims are removed from the Dana 44 carriers and pinion gears. They provide a good starting point when setting up new gears or installing a traction-adding device. The EVO tech crew transferred the old carrier shims over to our front and rear Eaton ELockers with new carrier bearings. The Eaton ELocker is an electric selectable locker that acts like a traditional open differential when the switch is turned off, making the traction adding device unnoticeable when driving on the street.
Setup bearings that have been bored out for a slip fit can be used to streamline shim adjustment when setting the correct gear mesh pattern and backlash. If you are careful and have a proper press and bearing puller, you can simply use the new bearings during the setup process.
There are only a few gear-cutting companies out there. Spicer gears are some of the best available. We went with a 5.38:1 ratio, which should work well with our 33-inch tires and Advance Adapters Saturn Overdrive. We don’t plan on making any long high-speed highway jaunts. The ring gear bolts are torqued to 55 lb-ft.
The Eaton ELocker and Spicer gears are loaded into the housing for initial fit up. Be careful with the 12V locker wires. You don’t want to smash them during setup or final assembly.
You have to drill a hole in the axlehousing for the 12V locker wires to pass through. The hole should be 1⁄2 or 29⁄64-inch, depending on the thickness of the area you are drilling through.
We used RTV sealant on the bulkhead fittings before pushing them into place. Test the Eaton ELockers and make sure the wires clear the spinning internals of the axle before installing the differential cover.
We capped both our front and rear Dana 44 axles with genuine Spicer differential covers. The 1⁄8-inch-thick steel covers are available new, complete with installation hardware and a gasket. Each Eaton ELocker includes a full wiring harness with a relay, wire loom, and a lighted rocker switch.
Once we took the axles home, we went to work replacing the old worn-out ball joints with new Spicer parts. The lower ball joints always seem to wear out first, but we replaced all four front axle ball joints for good measure. Use a ball joint press to avoid damaging the knuckles.
Traditional U-jointed axleshafts have a lot of issues when used in a front axle with a locker. We always seem to have trouble keeping the U-joints, U-joint caps, and axleshaft yokes from coming apart. RCV Performance Products offers unique CV-style axleshafts for many applications that put those U-joint problems to rest. The high-quality RCV axleshafts are said to be twice as strong as stock. Plus, they’re just as tough when steered straight as they are at extreme angles where U-jointed axles are at their weakest. The RCV axleshafts come with a no-questions-asked limited lifetime warranty and are made right here in the USA.
Our RCV axleshafts require that the tip of the lower ball joint stud is ground flush with the nut. The easiest way to do this is to install the knuckles, remove the steering stop, and use a small grinder to get in there. Then, you can pull off the knuckle and remove just a bit of material from the upper ball joint to ease installation of the RCV ’shafts. Full instructions are available on the RCV website.
The RCV axleshafts fill up the knuckle and need to be assembled in the proper order for everything to fit. Insert the RCV axleshaft into the housing, slide on the orange RCV boot, and then load the RCV Performance Products CV assembly into the knuckle. Installing the knuckle with the CV in it is the hard part, as it almost requires three hands. RCV has a couple of installation videos online; one of them makes it look deceptively easy. After you get the knuckle in place, you can pull the boot over the CV, install the spindle lip seal hardware, and then insert the stub shaft. This process was the only way we could get it all together. Grease the RCV boot liberally to help with the installation. Torque the lower ball joint to 80 ft-lb, the upper collar to 50 ft-lb, and the upper ball joint nut to 100 ft-lb, in that order.
A large roll pin is used to retain the RCV stub shaft. Position the splined stub into the CV so that the roll pin holes line up. Use a drift and hammer to tap the roll pin into place before installing the spindle—You’ll need the room to move the shaft around for the installation.
The RCV ’shafts allow the use of standard Dana 44 spindle seals, bearings, and hardware. Since we were swapping to a 5-on-5.5 lug pattern, we installed small-bearing Dana 44 spindles (Spicer PN 706528X). These can be found on early-mid ’70s GM trucks. Our stock FSJ brake caliper brackets and brake calipers are retained and reused.
The 5-on-5.5 hub and rotor assemblies and wheel seals are from a ’76-’86 Ford F-150 or fullsize Bronco. The wheel bearings are from the small-spindle GM truck.
The RCV Performance Products CV joints are easily serviced via grease fittings installed at the ends of the stub shafts. To access the fittings, you need to partially remove the locking hub or the driver dust covers. Only a few squirts of RCV High Performance Synthetic Moly CV Grease is needed every six months or so.
You can run internal-spline locking hubs (A) or full-time RCV drivers (B) (PN D44-SLUG) with the larger 30-spline RCV axleshafts. RCV offers its Locking Hub 300M Gear Upgrade (PN D4342) that fits into Warn hubs. The heavy-duty, alloy steel, 30-spline gear (C) replaces the weaker 19-spline part (D). The locking hub gear swap is easy and only takes a few minutes.
RCV offers custom and stock-application rear axleshafts too. We decided to stick with the stock ’shafts for now. The rear axle bearings appeared to be in good shape, so we cleaned them up, greased them, and slammed the ’shafts home. We’ll do a quick rebuild on the drum brakes, but eventually we’ll likely make the switch to discs. Keep an eye out for upcoming build segments; we still have lots to do to our GPW.