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Bulletproof One-Tons for Pugsley the Scout

Posted in How To: Transmission Drivetrain on May 21, 2018
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Photographers: Trenton McGee

It takes but a quick glance at Pugsley, our 1964 Scout 80 project (bit.ly/2KMx0Zi), to realize that we’re cheap bastards. Pugsley looks like it should be quietly rusting away in a field somewhere rather than leaving tractor bits on a trail. We’re all about budget, but we also like going four-wheeling more than working on our 4x4 trailside. So when it comes to components that could impact our ability to keep going, we tend to favor strength over saving a buck. With V-8 power and big tires in the plans, we knew the axles were going to take a lot of abuse. It didn’t take a rocket doctor to figure out we needed to invest in quality axle components.

But that’s not to say that the foundation for Puglsey’s axles weren’t obtained on a budget. We got our hands on a bare front Chevy Dana 60 housing through some horse trading after our search for a reasonably priced complete Dana 60 came up short. Heck, finding a Chevy Dana 60 at any price these days is getting difficult. Since we knew we would be replacing most of the guts, starting with a bare housing made sense. For the rear, a 14-bolt is the definition of budget beef, so we plucked a late-model variant with disc brakes out of the local self-service junkyard for under $150.

These are all the ingredients for serious axles with some assembly required. The Chevy Dana 60 housing was obtained bare, so we had is sandblasted inside and out before tapping Randy’s Ring & Pinion for a set of Yukon 5.13 gears, a Grizzly locker, wheel hubs, spindles, bearings, locking hubs, kingpins, and more. Beefy Reid Racing knuckles are strong enough for an Ultra 4 car, so they should be more than good for our old beater. Same goes for RCV front axleshafts, which offer unbelievable strength regardless of the steering angle. Out back we opted for a matching set of Yukon 5.13s and a spool for our junkyard-fresh 14-bolt.

Once the base axles were obtained, we turned to a few key suppliers to build the axles of our dreams. Randy’s Ring & Pinion is pretty much one-stop shopping for axle parts no matter what you’re working on. We turned to Randy’s for much of the Yukon components you see in this article. Our Dana 60 didn’t come with knuckles, so we went to Reid for some racy bits that will keep Puglsey pointed in the right direction and will more than withstand the stresses and strains of huge tires with hydraulic-assist steering. And because axles in general—and front axleshafts in particular—take a beating, we opted to eliminate a weak link permanently with a set of 35-spline front shafts from RCV Performance.

Check out how the entire combination went together, and stay tuned as we get ready to swing these bombproof big boys into their new home. While there are a few more high-zoot tricks to build even beefier axles than what we created here, much of it is racecar stuff and overkill for your average trail rig. With this combo, 40s and 400 hp won’t be a problem, ever.

After the front housing was thoroughly cleaned, the next step was attaching the ring gear to the Grizzly locker. The Yukon master overhaul kit included new ring gear bolts and Loctite, both of which we used. The ring gear gets torqued to 110 lb-ft. Be aware that there’s a carrier break with the Dana 60 and both thick and thin gearsets are available in 4.88s and 5.13s. It’s easy to order the wrong combination if you’re not careful.
Since we had no carrier shims to measure as a baseline, we needed to figure out a starting point. We set up a dial indicator like so and then used a pry bar to push the carrier to one side and then the other to measure the distance. We came up with 0.100 inch, which we split in half, and then we added 0.004 for carrier preload. This ended up being very close to perfect, requiring just a few minor adjustments during trial setup.
We have a lot of ground to cover, and we’ve detailed setting up gears before, so we’re not going to get into many specifics here. We were impressed that we were able to get a good pattern for the front on only our third shot, despite not having any of the original shims from the old gears. We got lucky, but this also is indicative of the consistency and quality of the Yukon gears and Grizzly locker.
One of the more tedious but important parts of setting up gears is pinion bearing preload. Too little and you end up letting the pinion walk around in the housing; too much and you burn up bearings. The spec for new bearings is 16- to 30 lb-in, and we eventually got ours to 25 lb-in. The Yukon master overhaul kits included all the necessary Timken bearings and seals, not to mention a great selection of shims.
We were impressed that the Yukon overhaul kit included new inner axle seals for the front. Usually these have to be ordered separately. Installing the seals without damaging them is tricky, but here’s the hot setup we’ve used that works. Use a large socket or some tubing as a driver, and have someone knock the seals in place from the opposite side while keeping everything lined up and even.
There’s probably a fancy tool or a great big Allen wrench to install the kingpin cone, but we had neither of those things. We figured out that a 14mm lug nut is pretty close to the right size for the cone, so we welded together this nearly free special installer tool. For a no-weld option I used an extra-long 1-ton 9/16-inch lug nut inside a 7/8-inch socket.—Ed. It’s not pretty, but it worked. Torque spec on the cones is tight-as-you-can-get-it.
The Yukon kingpin kit includes everything needed to replace all the wear parts on the kingpins, but the Reid knuckles include one important upgrade that we opted to use. Instead of the stock nylon bushing, we opted for the bronze upper bushing for strength and longevity. We’ll probably end up with steering arms that attach to the kingpin bolts, but we went ahead and assembled the kingpins anyway.
In addition to axle internals, Randy’s Ring & Pinion offers most other axle-related components. We turned to the company for wheel hubs, spindles, wheel bearings, and seals since we didn’t have any of that stuff. These are all items that could be reused (except for the seals) if in good shape, but it’s also nice knowing that everything is brand new. We ordered new rotors from the local parts store, along with wheel studs.
We knew that we were bound to forget something when building axles from scratch, and we were right. The Reid knuckles don’t include spindle studs, which are special fine-thread components with heads that are thinner than normal. This is not something that most local places are going to stock. Keep this in mind so that you don’t get held up on a deadline like we did.
Rather than using conventional U-joints to connect the inner axleshafts to the stub shafts, RCV uses beefy CV joints, hence the unique shape and distinctive orange dust boot. The CVs are a combination of chromoly and hardened steel, and unlike U-joints, they offer full strength regardless of the operating angle. The CVs come greased, but it’s a good idea to add more when assembling the shafts.
The inner axleshaft is held in the CV with an internal snap ring, so assembling the axle is as simple as sliding it into place. The orange dust boot is too big to fit through the hole in the knuckle. It needs to be positioned between the knuckle and the inner C, and then the axleshaft assembly slides through it before being seated on the bell. Since we were missing the spindle studs, we opted to do this later.
Compared to all the bits and pieces for the front axle, the 14-bolt rear is a piece of cake. Pulling the cover of our junkyard axle revealed rancid gear oil, a magnet covered in metal “fur,” and a Gov-Loc limited-slip. The latter would have been a bummer had we opted for a Grizzly locker, as it reuses the stock open carrier. If you’re planning on locking a 14-bolt, it’s a good idea to pop the diff cover and make sure you have an open carrier because many late-model 14-bolts have a Gov-Lok that’s not compatible with most aftermarket lockers.
Normally we would use some kind of locker for the rear, but for this build we opted to go with a spool. Why? Mostly because we’ve always wanted to try a spool in a crawler. There are mini-spools available for 14-bolts, but Yukon also makes this super-beefy, full-case spool that we had to have. A spool mechanically locks the axleshafts together with the ring gear, so there will never be any ratcheting, slippage, popping, or banging. The gears are 5.13s to match the front.
The 14-bolt axleshafts are 30-spline, but the splines are much bigger than that ones you will find in a Dana axle. Chromoly 14-bolt axleshafts are available, but it’s also incredibly hard to break a stock rear shaft. We cleaned and inspected the factory shafts, then gave them the nod to go right back into service.
The pinion support on a 14-bolt drops out of the housing, making it easy and convenient to install a new pinion and bearings. Pinion bearing preload is normally set with a crush collar, which is kind of a pain and not terribly reliable. We opted to utilize one of Yukon’s crush collar eliminator kits, which makes preload easier to adjust with conventional shims. Also be aware that 14-bolts use a different inner pinion bearing depending on the year, so it’s helpful if you know roughly what year truck your axle came from when ordering an overhaul kit.
Another nice thing about a 14-bolt is that carrier preload and adjustments are made with spanners built into the housing. Making changes to carrier position is as easy as rotating the spanners to shift the carrier right or left—no shims needed. Pinion depth is controlled by shims positioned between the pinion support and the housing. Once again we got lucky and had a good pattern after just two or three adjustments for pinion depth.
Most overhaul kits are not going to include new outer axle bearings, but if you’re going through all the trouble of installing new gears and inner bearings, why wouldn’t you do the outers as well? The nasty gear oil in the axle was likely original, and judging by the condition of the gears, the axle had a lot of miles on it. There’s evidence that one of the wheel seals was also leaking, so we added outer axle bearings to the to-do list.

Sources

RCV Performance
Loves Park, IL
815-877-7473
RCVperformance.com
Reid Racing
Pleasant Hill, CA 94523
925-935-3025
http://www.reidracing.biz/
Yukon Gear and Axle
888-905-5044
www.yukongear.com
Randy's Worldwide
866-631-0196
randysworldwide.com

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