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Mix & Match Axle Build

Posted in How To: Transmission Drivetrain on May 7, 2018
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There are a million axles out there, from insufficient options we wouldn’t wish on our enemies (we’re looking at you, Dana 35) to stuff that’s overkill for 99 percent of the vehicles on the trail (cough Rockwell cough). None, however, are as ubiquitous as the Dana 44, and for good reason. Dana 44s are available for front and rear applications in a variety of widths in five-, six-, and eight-lug bolt patterns to make a matching pair with everything from a Ford 9-inch to a Toyota axle, and they don’t cost an arm and a leg.

Even after deciding on a Dana 44 though, the gamut runs from grabbing an axle out of a junkyard and hoping for the best to calling up a supplier such as Currie Enterprises, Dana, Dynatrac, G2, or a host of others to have a brand-new bolt-in axle assembly delivered in a crate. We were looking for the middle ground, trying to determine where it makes sense to source used parts to save cash and what upgrades are essential to provide the strength necessary for our application.

We started with a used Dana 44 out of a 1970s F-150, a 64-inch-wide, high-pinion Dana 44 equipped with disc brakes and manual locking hubs. On half-price day at the local wrecking yard you can find axles like this for under $200, but that’s only the starting point. We worked with Aaron Lechner of Axleline to maximize our strength-to-dollar ratio using components from ARB, Motive Gear, Ten Factory, and Spicer. Our specific application consists of a 4,500-pound early Bronco with a mild V-8, automatic transmission, and 37-inch-tall tires.

Axleline started by disassembling and cleaning the entire axle assembly, right down to the locking differential. We had purchased a used ARB Air Locker that is the older three-piece design. Even though the used locker isn’t as strong as the newer two-piece RD116 Dana 44 Air Locker, the price fit our budget.

“There are a lot more factors to making a reliable axle than just tire size,” Lechner says. “Horsepower, transmission, gearing, intended use, vehicle weight . . . even tire and wheel weight. These are all details that should be considered.”

Not to mention perhaps the most important factor: driver finesse. The end result in an axle that is strong and reliable yet still built on a budget.

Axleline replaced the bonded seal inside our Air Locker and inspected the internals for wear. This cost approximately $100 in parts and $200 in labor, so keep those expenses in mind when comparing the cost of a used Air Locker to a new RD116, which costs approximately $900.
While you might be inclined to save money on a ring-and-pinion set, Lechner explained that budget gears often take longer to set up, so you really don’t save in the big picture. We sourced a 4.88 ring-and-pinion set from Motive Gear. They set up quickly and run quiet and cool right out of the box.
The full install kit from Motive Gear included genuine Timken bearings. We typically like to run Timken in American axles and Koyo bearings in Japanese axles. No-name Chinese bearings cost a little less, but considering the labor involved in changing differential and pinion bearings, we prefer to play it safe with quality bearings.
Motive Gear includes new ring gear bolts in the installation kits. Lechner installed them with thread locker and a torque wrench to combine the ring gear and ARB Air Locker. You can reuse ring gear bolts, but the risk isn’t worth the cost savings in this instance.
The pinion slinger is a small but critical component in high-pinion applications. This large-diameter shim sits in the gear oil and provides lubrication to the pinion bearings, which are not submerged. Motive Gear includes a new slinger in the installation kits, which is valuable since they often get destroyed when the old pinion is removed.
Lechner typically just uses a soft dead-blow hammer to install differentials with shims under the carrier bearings. ARB Air Lockers are unique though, in that the side with the seal housing places the shims outside of the bearing, so a case spreader must be used to prevent damage to the shims.
The bearing cap and housing must be drilled for the air line used to actuate the ARB Air Locker. ARB includes very detailed instructions, but we still prefer to leave these steps to a professional since you can ruin your entire axle assembly if this isn’t done properly.
One place you can save money is by running the factory axleshafts until they break since they are relatively easy to change. If your budget allows, Ten Factory 4340 chromoly axleshafts are far stronger than stock. The use rolled splines and have a black oxide finish that is perfect for wet or muddy environments, and they are backed by a 10-year warranty.
Our donor axle came with cast wedges on the tubes, which is fine since we intend to use radius arms. If you intend to use leaf springs or a three-link, look for an axle with welded-on wedges. Other common trucks and SUVs from Dodge, Chevy, and Jeep also had Dana 44 front axles, but they use a low-pinion design.
In addition to being crafted from superior materials, the yoke ears on the Ten Factory axleshafts have more material to ensure that they do not stretch or break. This is a common failure point on factory axleshafts.
While stronger U-joints are available, Axleline recommended Spicer 760X U-joints for our application due to price, strength, and low maintenance. The Ten Factory axleshafts use full-circle snap rings to retain the U-joint caps, which is a huge improvement over the C-clips found on factory axleshafts.
A variety of different yokes is available for Dana 44s to fit different-sized U-joints. Since we already had a 1310 driveline, Lechner recommend we retain the factory yoke (left) rather than upgrade to a new 1330 yoke (right). We do prefer yokes that use U-bolts rather than straps, as they are less likely to loosen over time.
Ball joints are not the place to try and save a buck. High-steer, hydraulic-assist steering and wheels with shallow backspacing can all lead to accelerated ball joint wear. Installation is labor intensive so it pays to do it right the first time. We’ve had very good luck with Spicer ball joints and used them again on this axle.
Typically, you can reuse the brake calipers on a junkyard axle and just turn the brake rotors, but we always install new brake pads. EBC pads provide increased bite for improved braking without the noise often associated with high-performance brakes. EBC makes rotors as well if you need them. And if you do need new calipers, they only cost about $20 each from your local parts house.
If you do get new rotors, we recommend purchasing new wheel studs at the same time. Now is also a good opportunity to match the size and thread pitch of your Dana 44 to whatever axle you are pairing it with.
We capped off the outers with Warn Premium Hubs, which feature all metal construction. These hubs are commonly found on older axles, although they are getting tough to find in wrecking yards as solid axles become less common. If you can’t find a used set to run, they cost less than $150 to buy new.

Sources

EBC Brakes
Las Vegas, NV 89120
702-826-2400
http://www.ebcbrakes.com
Motive Gear
Chicago, IL 60609
800-934-2727
www.motivegear.com
Warn Industries
Clackamas, OR 97015
800-543-9276
www.warn.com
Ten Factory
Chicago, IL 60609
800-934-2727
www.tenfactory.com
ARB USA
Renton, WA 98057
866-293-9078
http://www.arbusa.com
Axleline
775-870-9585
http://Axleline

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