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Budget 1-Ton Axle JK Swaps

Posted in How To: Transmission Drivetrain on January 8, 2018
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Like a growing number of serious off-road adventurers driving JKs, the owner of this Jeep swapped out the V-6 in his lifted and well-accessorized Wrangler for a 385hp Chevy Silverado 6.0L LS backed with matching 6L80E automatic. At the same time the rig got 37-inch tires. Tough trail use and pounding the dunes led to a year-long battle with one axle-related failure after another: blown front and rear diffs, broken and twisted axle shafts, failed U-joints, burned bearings, and even a bent axle housing. It was obvious the Jeep’s axle game had to be stepped up. The owner decided to go with a high-pinion, 35-spline, 1-ton axle swap. The trade-off in increased unsprung weight would be worth the benefits the bigger housings bring to the table.

The out-of-the-box, bolt-in choices for 1-ton housings include Dynatrac’s Hard Core ProRock 60/60s, Spicer Ultimate Dana 60s, Currie’s RockJock III 60s, and TeraFlex Tera60s. The price to go this route would just begin at about $10,000 per set, depending on the brand and options—not including costs for labor and any related upgrades that go along with slipping heavy-duty running gear under a JK.

However, for those who have the mechanical and fabrication skills to undertake the job and are willing to put in the time, using Artec 1-ton swap kits with junkyard-sourced housings can save a whole bunch of build bucks. This saved money can be used for upgrading the shocks, suspension, tires, and wheels to maximize the performance gained from installing the beefy, do-it-yourself 1-ton housings.

Too much power and not enough beef in the running gear (coupled with 37-inch tires) had put our ’09 JK Rubicon out of action numerous times on the trail and the highway since the V-6 was swapped out for a 385hp 6.0L GM LS and matching 6L80E automatic a year ago. It was high time for a change.

We will follow the axle prep and swap process end to end, so to speak. A Dana 60 yarded from under an ’04 Ford Super Duty and GM 14-bolt rear from an ’07 Silverado 2500HD were cleaned, rebuilt, massaged with the CNC-machined Artec parts, and slid underneath in place of the stock 44s. It was a weeklong project in the Evolution Auto shop.

Why the 60/14 combo? “I like to use the ’99-’04 Super Duty front housing because its 69 1/4-inch width matches closely with the Rubicon’s track,” Scott from Evolution Auto explained, as he prepped both of the junkyard housings for the big swap. He continued, “And I like the GM 14-bolt out of that era’s Silverado/Sierra 2500HDs because that housing doesn’t create any clearance issues with the JK fuel tank like a Dana 60 would—and the 14-bolt is stouter than a Dana 60.”

Donor housings in hand, we began by dropping the JK driveshafts, removing brake assemblies, clamping off brake line hoses (it’ll get new discs/calipers front and rear), removing the suspension, and rolling out the factory housings. That was the quick, easy part. Nearly 40 hours of shop time later, our JK was ready to tackle whatever off-road challenges awaited.

Our 1-ton conversion was based around a junkyard-sourced Dana 60 front from an ’04 Ford Super Duty and a 14-Bolt GM rear from an ’07 Chevy Silverado 2500HD to keep front/rear track as close as possible to that of the stock JK. We paid $750 for the pair.

The Artec conversion kits are generally well illustrated and the parts are laser-etched with numbers, so it’s easy to figure out which piece goes where. In essence, it’s a build-by-numbers process that involves a considerable amount of welding, along with the grinding, as not all pieces fit all housings exactly the same. As we planned from the start, the money saved by going the build-it-yourself route was then used for completing our big-boy axle swap with the appropriate shocks, tires, wheels, brake, and steering upgrades to take advantage of the 1-ton conversion.

Having a two-post hoist, air tools, a very talented tech, and a fully equipped shop like Evolution Auto really helped smooth out the 1-ton axle swap process—right from the start when we dropped out the stock Dana 44s. But that doesn’t mean it can’t be done in your own garage if you have the welding and mechanical skills.
It took several hours to prep both housings prior to starting the conversion, removing years of rust, grease, dirt, and OE brackets. After the housings were ready, Evolution Auto’s Scott Daniels set the Dana 60 in a stand he built and rotated the pinion upward to three degrees. Then the Artec Industries truss was both centered and leveled on the axletube. The truss set the stage for every other bracket and gusset welded onto the Dana 60 housing.
We found Artec’s Dana 60 truss didn’t have any provision for the housing’s vent tube. Scott made a notch in the gusset and used a brass fitting to make it work. If we were to do this again, we would drill a hole in the top face of the truss so the OE fitting could be reused.
During the pre-prep fitting work on the Dana 60, Scott noticed the spring perch on the driver side needed to be trimmed off, so he carefully removed two inches of it to allow the JK’s new steering components to fit.
Once the Dana 60 truss was properly located, the long process of tack welding the several dozen numbered pieces in the Artec conversion kit ensued. Full welds would come later. The instructions that came with the kit were well illustrated, and for the most part, easy to follow.
The shock-mounting brackets were welded on next. But before that could be done, we had to trim off a piece off the differential webbing to get the driver-side bracket to fit properly into the alignment slots in the Artec truss. As we strived for close fits all around, we had to trim and grind several other pieces in our kit so they fit the housing to our liking.
All of the new bracketry and truss on our front HD housing had to be fully welded. But that couldn’t be done until housing and Artec parts were properly heated so the dis-similar metals would shrink at similar rates as they cooled to prevent weld separation. We kept the cast-steel pumpkin preheated between 400-415 degrees F while Scott welded the truss in the adjacent areas, alternating sides.
Jp Pro Tip: The welded (and hot!) housing must be immediately wrapped with a fireproof blanket, which was purchased at the local welding supply store, and then covered with several other thick blankets so the housing slowly cools down overnight (12-16 hours). After that we could begin the next stage of the front axle modifications.
While the Dana 60 was cooling its jets, we turned our attention to the GM 14-bolt rear housing. Scott had set the pinion angle to nine degrees (after premeasuring the pinion angles before removing the stock axles) on the stand, positioned the Artec truss at 0 degrees (level), and then double-checked that the truss was perfectly centered before tack welding it in place. Our measurements were 15 9/16 inches from end of truss to backing plate.
We had to position the spring bucket perches on the 14-Bolt at 0 degrees to be in alignment with our JK’s 6-inch lift. This required cutting off the handy Artec alignment tabs so the bumpstop plate could be rotated into the proper position for our build. It can be easy to mix up the bumpstop plates, so we made sure #17 went on the passenger side of the axle housing before it was tack welded.
Sometimes a little deviation from directions is necessary, as was the case when we noticed Artec spacing on the spring perches and bumpstops would have placed the brackets against the axle flange where we couldn’t get the nut on the control arm bolt. A piece of scrap 1/4-inch flat stock used as a spacer between the bumpstop and track bar brackets helped get the correct spacing.
Another Jp Pro Tip #2: The Artec kit required welding together the track bar bracket. A piece of 1 5/8-inch OD square tube stock clamped between the two pieces ensured they stayed perfectly square when welded together.
Each conversion is going to be slightly different because of lifts and so forth. But on our JK the lower brackets on the GM 14-bolt ended up being positioned 3 5/8 inches from the flanges, when positioned in the alignment notch conveniently cut into the Artec-supplied pieces.
Once cooled down, the Dana 60 was unwrapped and the remainder of the brackets welded into place, along with the bumpstops and spring retainers. We became very efficient with a MIG welder by the time this project was done.
When the upper control arm brackets were welded into place, we used a small piece of scrap 1/2-inch flat stock to space it properly and to make sure both pieces were square before tack welding.
Once we had all the brackets welded on the two housings, a floppy disc and patience paved the way to painting them. Sanding and cleaning also allowed us time to double-check all of the welds one last time before paint.
Scott has built a lot of differentials over the years at his Evolution Auto shop, so it was business as usual when he installed ARB Air Lockers and Nitro 5.13 gear sets in the Ford Dana 60 and GM 14-bolt headed for our JK. Jp Pro Tip #3: When installing new gears, Scott recommends lightly running a flat file over the mating surface on the ring gear before installation to ensure runout is consistent around the perimeter.
Installation of ARB Air Lockers required inserting 1/4-inch pipe fittings into the tops of the pumpkins. The Artec trusses block the normally used hole location on both housings, so we had drill and tap holes on the flat surfaces opposite (rearward) from where they’d normally be located. We cleaned out any metal shavings before installing the gears.
Our 14-bolt housing had to have about a 1/4-inch of the inner webbing ground away on both sides of the driver-side axletube to give the proper clearance for the ARB Air Locker/Nitro ring gear. We noted Scott set the backlash on our 14-bolt at 0.006 inches, and preloaded the pinion to 28 in-lb.
A two-post hoist and a roll-around axle stand like Scott built, along with a couple friends from the Salem Jeep Club, made it a lot easier to install the beefy axle housings under the JK. The 14-bolt rear assembly went in easily. The Dana 60 took a little more muscle and time. But the Artec 1-ton kits positioned everything where it needed to be on both ends.
In order for the ABS and computer system to work with the GM 14-bolt, we had to use a lathe to turn a shoulder on each eight-lug hub so we could install a 52-tooth tone ring, which matched the ones that came on the Currie front unit bearings.
After rebuilding the rear brakes with new rotors and pads, we slid in Skyjacker 6-inch Softride coils in place of the 4-inch coils and 2-inch lift blocks; installed a Rubicon Express adjustable rear track bar; and used aFe Sway-A-Way 2.5-inch piggyback reservoir shocks to maximize both travel and ride quality.
Our JK 60/14 housing upgrade also necessitated new drivelines, for which we turned to Tom Wood’s Custom Drive Shafts for the perfect pair. Our new ones have beefy 1350 U-joints, compared to the stock 1310s we originally were running.
There were a lot of modifications to the Artec-trussed Dana 60 once it was slid under our JK. We upgraded to Currie JK 1-ton unit bearings with 52-tooth tone ring and 35-spline stub shafts; used a Weaver Fabrication Hi-Steer Dana 60 Machined Knuckle; and installed a PSC hydro-assist steering system, JK Big Brake Booster and master cylinder, new rotors, and Warn Premium hubs. We also had a custom track bar built, and relocated its mount 1.5 inches forward on the frame to clear the beefier housing.
We couldn’t be happier with how the new axles and related upgrades worked on- and off-road. Not only has this ’09 JK Rubicon gained a tremendous amount of drivetrain strength with the 1-ton axles, the 40-inch Cooper Discoverer STT Pros hanging off the ends also made it an easy day on trails that had previously caused some concerns.
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Sources

Currie Enterprises
Corona, CA 92880
714-528-6957
http://www.currieenterprises.com
Rubicon Express
Rancho Cordova, CA 95742
877-367-7824
www.rubiconexpress.com
Sway-A-Way
Chatsworth, CA 91311
818-700-9712
www.swayaway.com
PSC Motorsports
Azle, TX 76020
817-270-0102
www.pscmotorsports.com
Warn Industries
Clackamas, OR 97015
800-543-9276
www.warn.com
Nitro Gear & Axle
Sacramento, CA
916-673-6464
www.nitro-gear.com
East Coast Gear Supply
919-672-2705
http://www.eastcoastgearsupply.com
Artec Industries
855-278-3299
http://www.artecindustires.com
ARB
866-293-9078
www.arbusa.com
Ruff Stuff Specialties
916-600-1945
http://www.ruffstuffspecialties.com
Tom Woods Custom Driveshafts
877-495-6468
www.4xshaft.com
Weaver Fabrication
530-351-4485
http://www.weaverfabrication.com
Evolution Auto
Keizer, OR
503-949-7546
https://www.facebook.com/Evoauto/

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