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Junkyard 1/2-Ton Axles

Posted in How To: Suspension Brakes on February 13, 2017 Comment (0)
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I love junkyards. I’m not sure why. They are dirty, smelly, somewhat sad places where vehicles go to be dismembered. A place where 4x4s end up when someone has decided that as a whole, they are not worth trying to fix. I guess my like of junkyards has to be because the parts that fill their chain-link enclosures are a gamble and thus generally fairly inexpensive. The buyer has to roll the dice or have some knowledge about what is good enough to be reused and what needs to be relegated to the scrap pile to be melted down. I also like the idea of repurposing things, recycling, avoiding expending unnecessary resources on making new parts when old parts are good if not better. Before you accuse me of being a tree-hugging hippy, realize that reusing good parts and rebuilding tools and machines we as humans rely on goes back well before 1960 and the flower children. At the end of the day it just makes sense (and it’s a good way to save money).

As you can tell, these parts are junkyard fresh and partially disassembled. The front axle is a Dana 44 from an early 1970s F-series Super Cab 4x4. Features include a 5-on-5 1/2 bolt pattern; high-pinion, 1/2-inch-thick axletubes; and leaf springs rather than coils and radius arms (like other F-series 1/2-ton 4x4s). A slightly different yet more common eight-lug axle with many of the same benefits could be pulled from a 1970s F-250. The rear axle is a late 1970s F-100 Camper Special. You want to make sure any 9-inch you buy has 31-spline shafts and big carrier (3.063-inch od) and wheel bearings. You can also look for a nodular centersection for the ultimate in junkyard parts strength. Our axle has big wheel bearings and smaller carrier bearings (2.892-inch od). Since our rockcrawler is powered by a V-6 with an automatic transmission, we are going to roll the dice and run the non-nodular Ford centersection with smaller carrier bearings.

The junkyard and the repurposing of parts remind me of a cliché. An old lady gets a lecture from a kid working at a grocery store about recycling aluminum cans. The old lady responds, “Well, when I was your age we washed and reused glass bottles for milk and soda every day of our lives.” What’s my point? Hell, I don’t know, but it seems to me that reusing old heavy-duty parts that still have life is way better for the world than melting them down to be made into modern light-duty equivalents even if those new parts are shiny and smell fresh. This tech article revolves around reusing some older parts and adding modern upgrades that will make for axles that are plenty strong for a family rockcrawling rig I have in my head.

Here is one reason why this axle is better than a modern Dana 44 high-pinion despite the fact that it was bent. Modern Jeeps (the only modern 1/2-ton vehicles in America with a solid Dana 44) have larger and stronger front ring-and-pinions than old-school Dana 44s, but their axles have to be a lot lighter in construction to keep the overall vehicle weight down for fuel economy. That means the housings are far weaker simply because they use a lot less material in the axletubes and in the castings. You can see how thin this cracked JK Dana 44 was before it was repaired in the field. Larger pinions and larger ring gears of the JK Dana 44 sound great on paper, but if the housings (and inner knuckles) are so wimpy that they fall apart around these larger parts, what have you gained? This may not be the case with an aftermarket JK front Dana 44 housing, but good luck finding an aftermarket used housing at a junkyard.

The front axle is an odd duck and at the end of the day wasn’t all that great a deal. It’s a cool axle, a Ford F-150 (or F-100) Super Cab Dana 44. That means it’s a five-lug, high-pinion axle with leaf spring perches (as opposed to radius arm brackets) and heavy-wall tubes. The truck the axle came from was in a self-service junkyard near my house. Most of the body of the truck was gone, but someone had passed up this desirable axle. I would only realize why after I’d gone to the trouble of pulling it and paying for it. It was bent. Still, this bent axle has lots of good characteristics, and I used it as a basis for a story on straightening a bent axle (this is something that can be done and, with modern lightweight axlehousings, will become more and more necessary). That story ran in Jp magazine (Oct. 2014), and I have since collected parts from various sources and paired the Dana 44 axle with a Ford 9-inch F-100 rear axle. The plan was simple: Build some junkyard axles that would be durable enough to pull a family-minded rockcrawler on the trails of the Southwest with 37-inch tires. I built what might be the ultimate Dana 44, and a fairly pedestrian Ford 9-inch with parts from Drive Train Specialists (DTS), Reid Racing, RCV, Warn, RuffStuff Specialities, and others. At the end of the day I don’t have to worry about breaking the front axle in the truck these axles are planned for, and the rear axle is ripe for upgrades if necessary down the road.

With our heavy-duty, high-pinion Dana 44 front axle all straight and clean we started gathering heavy-duty parts to match the build. We ordered up a set of 5.13 high-pinion (sometimes called reverse rotation) gears, an Eaton Detroit Locker, and a master install kit from Drive Train Specialists (DTS). The reverse rotation in a front axle is stronger than a regular rotation (low-pinion) gear up front. With a quality ring gearset, shims, bearings from a place like DTS, and the right tools, getting a good pattern is easier than it would be with cheap components. Still, getting a good pattern is next to impossible without the experience that only comes from setting up gears. A better pattern on quality parts means parts will last longer despite the abuse that we know these parts will see, and knowing how to read patterns is something you can spend a lot of time learning about.
Once we were happy with the settings on the front ring-and-pinion we torqued everything to specifications with red thread locker and capped off our front differential with a 3/8-inch-thick differential cover from RuffStuff Specialties. That allows us the peace of mind to bounce the axle off rocks when on the trail. A coat of gray spray paint gives this axle a fresh and industrial look that won’t be too gaudy on the trail.
Another benefit of the Ford Dana 44 is the size of the spindles and knuckles used on these housings. We wanted high steer arms to help with steering angles, so we ordered up a set of these nice orange Reid Racing Ford outer knuckles. The hole for the Ford five-bolt spindles used on these axles allows more clearance than the GM/Jeep/Dodge Dana 44 six-bolt spindles. That makes installing axleshafts that much easier in our axle. Beyond that Reid casts these knuckles with extra material and ribbing out of ductile iron. There is also a fourth bolt hole for the high-steer arms as well as two steering stops
The evolution of Dana 44 axleshafts went from stock parts, to stock parts with larger U-joints, to chromoly axleshafts with larger U-joints, and then to chromoly U-joints, right up to these modern RCV Performance Ultimate CV axles. These parts use aircraft-quality, high-alloy steel and a CV joint that has six bearings as opposed to two bearing cups found on a traditional U-jointed axle. These axles make this Dana 44 incredibly strong especially in combination with the heavy-duty housing and the Reid knuckles. Also RCVs are just as strong when turning (at a max of 45 degrees) as they are when the wheels are straight. U-joints bind and become weaker the farther you turn. Rockcrawling does not involve much driving in a straight line, so these RCVs are a great upgrade for any rig built to be abused.
The order of these four parts is critical to keeping dirt and water out of the back of your Dana 44 hubs. First (towards the differential) is a steel dust shield that is an interference fit on the axle stub shaft. Then there is a rubber seal that rides on the shoulder of the dust shield and seals against the back of the spindle. Next, with the inner taper towards the diff, is a plastic washer, and another sweeper seal that fits into the back of the spindle. It’s a good idea to lube all these up with a little grease prior to installation.
That last tiny seal should fit in the back of your spindle with the lip facing the differential as shown here.
The spindles that came with our junkyard axle had seen better days, having been literally hammered on and off a few times. DTS has plenty of Yukon spindles in stock for our Ford Dana 44 (PN SP700004). Also check out the custom high-steer arms from Offroad Design attached to the Reid Racing knuckle using four studs. That will help keep the draglink up out of harm’s way and at less of an angle to reduce bumpsteer.
Warn Premium locking hubs are the pinnacle of locking hub performance. RCV Performance Ultimate CV axles use 30-spline stub shafts as opposed to regular Dana 44 stubs that are 27-spline. In order to make our Warn Premium hubs work with the RCV axles, RCV sent us its Locking Hub 300M Gear Upgrade. This upgrades part of the Warn locking hub with a 30-spline 300M alloy steel locking hub gear. Installation in the locking hubs is easy.
With the front Dana 44 axle almost complete it was time to focus on the rear Ford 9-inch. We started by bolting the third member to our steel work bench to install the 5.13 gears with an Eaton Detroit Locker, crush collar eliminator, and all new bearings in our DTS-supplied master install kit. The 9-inch centersections are relatively easy to work on thanks to their removable (and shimable) pinion cartridge and carrier bearing spanners. The design allows for practically infinite adjustments. Ford 9-inch axles are also pretty darn stout when you consider their ring gear size and our axle’s factory 31-spline shafts.
Since our junkyard-fresh F-series 9-inch had unknown miles on it, we decided now was as good a time as any to change out the wheel bearings on the axleshafts. We were able to get the old bearings off using an angle grinder with a cutoff disc and our shop press to install the new bearings and retaining ring. We are also installing a disc-brake conversion kit from RuffStuff Specialties. We used some washers between the bearing retainer and the axle flange to make up the difference for the unused drum backing plate.
Adding disc brakes to a Ford-9 inch rear axle is fairly simple with a little knowhow and some parts, and even easier with help from RuffStuff Specialties and its very comprehensive line of disc brake conversion kits. We ordered up one of RuffStuff’s Ford 9-inch Weld On Disc Brake Kits (PN R2047) for our rear axle. The kit comes with just about everything you need for the swap, including rotors, calipers, brake pads, brake hoses, clips, and bolts. We assembled one of the brakes for mockup so we could tack-weld the bracket in place once the rotors and axles were assembled.
For this disc brake conversion the rotor has to be on the back of the axle flange. We used 1976 F-100 4x4 front wheel studs from our local parts store to hold the supplied rotors to the factory Ford shafts. These were the only parts we needed that were not included in the RuffStuff Specialties kit.
With a good idea of where the supplied brake rotors would mount on the inside surface of the Ford-9-inch axles, we used our shop press to drill a 1-inch hole in each rotor to help with accessing the retaining hardware that holds the bearing retaining plate to the axle.
Ford 9-inch axles use a bearing retaining plate to hold the bearing into the axle end. Usually a special T-bolt holds the plates in place. An old trick is to use a grinder to clearance one side of a Grade 8 bolt in place of the T-bolt. Here you can see our Grade 8 hardware as well as the washers we used to make up for the space we lost when we got rid of the drum brake backing plates.
With everything in place we mocked up the weld-on caliper brackets on the freshly installed rotors. You can squirt a little compressed air into the caliper to clamp the brake pads against the rotor and true up the whole shebang before heavy tack-welding it in place. Be sure to disassemble everything before finish-welding the bracket to the axle. You don’t want to burn up those new bearings and seals you just installed on the axleshaft when you burn the bracket in place.

Sources

Offroad Design
970-945-7777
www.offroaddesign.com
RCV Performance
Loves Park, IL
815-877-7473
RCVperformance.com
Reid Racing
Pleasant Hill, CA 94523
925-935-3025
http://www.reidracing.biz/
Warn Industries
Clackamas, OR 97015
800-543-9276
www.warn.com
Drive Train Specialists
800-521-0628
http://www.drivetrainspecialists.com
Ruff Stuff Specialties
916-600-1945
http://www.ruffstuffspecialties.com
Yukon Gear and Axle
888-905-5044
www.yukongear.com

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