 If you’ve been following Project Buckshot, you know that we are transforming this once stock, tame ’75 Bronco into a Swiss Army knife of off-road capability. It’s receiving a big lift, big tires, a strong new engine, steering upgrades, disc brake conversion, transmission and transfer case upgrades and much, much more. As with any rig that’s getting bigger tires and a more powerful engine, one must pay attention to the drivetrain, particularly the axles. In our case, we know that a combination of tough trails, big meats and more ponies under the hood would certainly put the stock axles into an early grave. And our new owner, TJ, would rather spend more time on the trail wheeling, than wrenching – can we blame him? In this two-part article series, we’ll zero in on the rear axle first, where we’ll stuff it with new, lower gears, a locker and upgraded axle shafts. For us, there was only one place to do all of our shopping: Randy’s Ring & Pinion, who by the way, offers every bit and piece we need to transform this already strong Ford 9” rear axle into one capable of taking the power and punishment that we’ll be throwing at it.
After a call with our friends at Randy’s Ring & Pinion, they suggested a complete set of Yukon components, replete with a set of super-strong 4.56:1 gears stuffed inside of a new carrier, a Grizzly locker, a set of 1541H high-alloy axle shafts and a rebuild master kit which comes with everything you (or a shop of your choosing) would need to complete the assembly.
| Before we get into the installation and review of our new Yukon components, we thought we’d take a paragraph to talk about the Yukon Gear & Axle division of Randy’s Ring & Pinion. First off, if you’re an avid do-it-yourselfer who wrenches on your 4-wheel drive or hotrod, you’ve no doubt heard the horror stories about the quality of Yukon components. Years ago, Randy’s Ring & Pinion set forth to enter the arena of selling their own product line of gears, axles and lockers under the Yukon brand name. Initially, they had problems with the durability and quality of the products. After several issues with the original manufacturing facility that they had chosen, they changed gears (pardon the pun) and have invested hundreds of thousands of dollars into better factories, better materials, better components, better quality assurance and more product testing, all designed to meet their more stringent specifications. The bottom-line, their current products are far improved over their first versions. Make no mistake, the editors at 4X4Review Off Road magazine are impartial and unbiased to manufacturers, nor do we specifically endorse any company or product line. We can say, however, that we have built several rigs with Yukon components after their improvements were made, and their products have taken every bit of severe abuse we can throw at it without failure. ‘Nuff said. |
With parts at the ready, we begin our rebuild of the Ford 9″ rear axle for project Buckshot.
| Installation – Yukon Gear & Axle, Ford 9″ Rebuild |
| Time: |
8 Hours |
| Tools Needed: |
assortment of wrenches and ratchet/sockets, torque wrench, line wrenches, hammer, jack, jack stands, gasket sealer, rags and cleaning solution |
| Difficulty: |
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Installation
 As with any project, be sure that you have all of the right products before you begin the tear down. Even more importantly, be sure that you safely secure your vehicle before beginning work. We chocked the front tires and jacked up the rear end, securing the vehicle by the frame rails with extra-tall jack stands. Note, we removed the rear axle from the vehicle so that it could be cleaned and painted. You do not have to do this. You will also have to have the unit bearings and backing plates pressed onto your axle shafts prior to the installation. |
 Start by removing the wheels and tires from the vehicle.
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 Since we removed the axle from project Buckshot, we disconnected the rear brake line, as well as the driveshaft. We also unbolted the axle from the leaf springs and removed the parking brake cables.
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  Drain the oil from the axle, then loosen the bolts on the third member.
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 Remove all of the brake components from the ends of the axle housing. We suggest taking several photos of the brake assembly on the early Bronco’s as their pretty complex in comparison to other manufacturers. We also recommend purchasing a good repair manual as re-assembly can be a bit tricky.
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  Remove the four backing-plate nuts and bolts from the drum brake backing plate and slide the rear axle shafts out of the housing.
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  We then suggest thoroughly cleaning and inspecting your axle housing and all components that you intend to reuse. Not only does this prepare the components for paint and reassembly, it will provide better visibility to any damage that may need to be repaired. Case in point, after cleaning our axle inside and out, we spotted a cracked shock mount. The mount was easily welded and is again ready for off-road duty.
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 At this point, your axle housing should be completely disassembled, cleaned and inspected. It’s now time for assembly of the new Yukon Gear & Axle components. Start by inspecting and cleaning (if needed) the third member.
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 Place a thick bead of silicone-based gasket sealer onto the opening of the axle housing where the third member will mate with it. Pay particular attention to where the studs are, and make a complete circle of gasket sealer around each stud. Carefully set the third member onto the axle housing. Use some thread locking compound and bolt it into place using a criss-cross pattern, then torque to spec.
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  Next, inspect and clean the new Yukon axle shafts. They come shipped with a rust-inhibiting coating that should be removed prior to installation. Brake clean or a comparable automotive cleaning solvent can be used to remove this coating. |
 Clean the axle tube ends and place a thin layer of light grease (e.g. white lithium grease) into the ends of the axle housings where the bearings will seat.
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 Place the drum brake backing plates onto the axle housing and then slide the new Yukon axle shafts part way into the end of the axle tubes.
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 Put a thin layer of gasket sealer onto the rubber lip of the unit bearing seal prior to inserting the axles all of the way. The unit bearings do a good job of sealing the axle shaft, but some do tend to leak a bit. This small amount of gasket sealer will help keep them from leaking years down the road.
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  Slide the axle shafts all of the way into the axle housing by rotating slowly until they slide into the third member. Using a bit of thread locking compound, install the locking nuts onto the backing plate bolts and torque accordingly, using a criss-cross pattern.
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  Reassemble the brake assembly and slide the drums over the brake shoes. Adjust your brakes according to your manual’s procedures.
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The Verdict
 Our Randy’s Ring & Pinion Yukon kit came complete with everything we needed; a completely assembled and adjusted third member with 4.56:1 gears and a Grizzly locker, new Yukon 4340 Chrome-Moly axle shafts, new high-quality unit bearings and the likes. The Yukon Gear & Axle Ford 9” drop-out (a.k.a. third member) is available in both small and large (3.06” & 3.25”) bearing sizes and is available in both a forged 6160 Aluminum or 4140 steel – we chose the latter for extra strength. The Yukon third member has increased rib thickness too, for added strength. The interior of the third member is also relieved to reduce or eliminate the need to grind for clearance of larger ring gears. It also comes with billet steel side adjusters. Lastly, when you purchase a completely assembled drop-out from Yukon Gear & Axle, it will be completely adjusted, making it a convenient bolt-on assembly.
Inside our third member, we chose a Yukon Grizzly locker, which is a full locker, similar to that of a Detroit Soft-Locker. The Grizzly lockers are super strong and available in 28 & 31 spline applications for our Ford 9”. The locker is made of 8620 high-strength metal internals for added strength and designed to take a  serious pounding. We also chose a set of Yukon ring and pinion gears which uses 8620 steel for high strength and long life. These gears are stronger than stock applications, are easy to setup and are designed to be quiet on the road too. The Yukon rear axles are 1541H high-alloy, semi-float designs made from high-quality materials that are claimed to be up to 25% stronger than stock 1040/1050 material axles, thus providing a stronger axle at a low cost. Our axles were upgraded from the stock 28 spline count to the stronger 31 spline count. The splines are also rolled, instead of cut, to provide 30% increased strength. The Yukon axles are also available in cut-to-length design to fit nearly any custom axle configuration too.
Overall, the installation of the rear axle components from Yukon Gear & Axle was a piece of cake and we like the new quality that Yukon puts into their products. We’ve abused Yukon Gear & Axle components for years without even the slightest problems.
The pre-assembled and pre-adjusted drop-out / third member is a God-send to the do-it-yourselfer making this project almost a bolt-on experience. Had the axle unit-bearings, seals and retaining plates already been pressed onto the axle shafts, this kit would have been a fully bolt-on project that even novice do-it-yourselfers could install with common tools.
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4x4Review Off Road Magazine
If you’ve been following Project Buckshot, you know that we are transforming this once stock, tame ’75 Bronco into a Swiss Army knife of off-road capability. It’s receiving a big lift, big tires, a strong new engine, steering upgrades, disc brake conversion, transmission and transfer case upgrades and much, much more. As with any rig that’s getting bigger tires and a more powerful engine, one must pay attention to the drivetrain, particularly the axles. In our case, we know that a combination of tough trails, big meats and more ponies under the hood would certainly put the stock axles into an early grave. And our new owner, TJ, would rather spend more time on the trail wheeling, than wrenching – can we blame him? 
