Project XtremeJ: Geared For Action With Currie, Bilstein, And More

It’s funny to think back on Project XtremeJ and where it started. When it first pulled into the office parking lot, it wasn’t much to look at. Bone stock and with a relatively clean body, it was aching for modification, and we took them on with gusto – lift, tires, armor, seats, and more. But the best was yet to come.

This summer, we got the Jeep back in the shop for some more surgery. This time, we were going for purely functional elements of the SUV, beefing it up so it could take on the rockiest, gnarliest terrain without breaking a sweat. Together with our friends at Currie, Bilstein, DaystarEatonDick Cepek, Dirty Life, and Omix-ADA, our Cherokee would get geared for adventure.

The plan was simple – the stock axles weren’t cutting it anymore, the Y-link steering was a major weak point, and several of the suspension and brake components could use some sprucing up. To those ends, we sourced a variety of parts, including Currie’s Ford 9-inch rearend and Dana 44 front axle; Bilstein 5160 shock absorbers; and Omix-ADA’s catalog of Jeep Wrangler JK brake parts, ball joints, and other odds and ends.

Parts Breakdown

If you want to put a Jeep guy in a bad mood, say “Dana 30” to his face. Watch as his happiness drains, as he thinks about the feeble axle tubes, the bend-prone steering knuckles, and piss-poor gearing. It’s a serviceable axle housing, sure, but scalable it is not.

Anything larger than 33-inch tires tends to push these housings to their breaking point, and hard off-roading has a way of making them buckle in the center. Traits like these make them stand out as terrible axles, and the Dana 35 shares much of the same depressing attributes. On Project XtremeJ, the Dana 30 front axle and Dana 35 rear axle were two problems that had to be solved.

Currie's manufacturing process is second to none.

Enter Currie Enterprises. In a similar vein to the modifications we did for Project Redneck, our approach to Project XtremeJ involved a Dana 44 front end with an Eaton E-locker, and a Ford 9-inch rearend with a Detroit Locker. With axles like these, the Cherokee could put power to the ground reliably and smoothly for years to come.

“Currie prides itself on craftsmanship,” said Currie’s Brian Shephard. “We use only premium materials and our technicians have years of experience under their belts. We also double-check every aspect of the build process, because we believe that quality control is everyone’s job.”

Armed with Currie-made 9-inch rearend and Dana 44 front end, Project XtremeJ will have the capability to tackle harsh terrain and make it back home.

Something else we got from Currie was a better steering setup through the Currectlync steering system (PN JK-9704). On Jeeps, the Y-link is a common sight. The steering arm meets up with a hole in the drag link, forming a “Y” shape, and handles steering well enough for stock applications. However, the design has trouble with larger tires, whose excess rolling weight can break the arms at their pivot points. The only way to really address the problem is to rip it out and start over with crossover steering, which is what the Currectlync system provides.

Parts Breakdown (cont.)

Currie’s axle, steering, and sway bar kits were important parts of our installation.

Crossover steering separates the drag link and steering arm into two different pieces, and beefs up the metal material to DOM tubing as opposed to mild steel. Our kit from Currie fit the bill perfectly and would give the SUV some much-needed beefing up on the steering front.

In the interest of giving our XJ a more refined undercarriage, we used Omix-ADA Wrangler JK parts – disc brakes, ball joints, and more – to bring it into the modern age.

Supporting the axles’ composition was Omix-ADA, who supplied brake components, ball joints, and other items to round out their completion. Many of these parts were for a Wrangler JK as opposed to a Cherokee XJ, and the reason for this is because parts availability is much more plentiful for the former. Thanks to these parts, the Jeep moves into the 21st century with disc brakes on all four corners and refreshed joints to tackle off-roading. “Upgrading to disc brakes make sense for Jeep owners,” said Omix-ADA’s Ryan Michael. “The ability to stop a vehicle is ramped up signifcantly compared to drum brakes.”

Bilstein supplied our XJ with 5160 shocks. With their aluminum construction and remote reservoirs, these shocks were built to put up with punishment.

On the suspension department, we went with a set of Bilstein 5160 shock absorbers (PN 25-187717). These shocks had the ideal setup for what we needed in a bolt-on solution. The chief benefit was the remote oil reservoir, which could be piggybacked onto the shock body or separated and mounted elsewhere if we so chose.

“Bilstein created the 5160 in an attempt to add additional cooling and off-road performance to the already stellar 5100 monotube shock,” said Bilstein’s Brent Davis. “By adding a reservoir, the shock gains oil volume, which increases its thermal capacity and removes some of the oil from the heat source, allowing for increased cooling. This results in a fade-free dampening experience.  By moving the dividing piston – in other words, the piston separating the oil and nitrogen charge – into the reservoir, you are able to gain additional travel in the same length shock.”

The added oil would help with better heat dissipation and mitigate the chances of cavitation during heavy off-road driving. Another benefit to the shock absorbers was the zinc plated exterior, which would hold up well against the outside elements.

Extended bump stops from Daystar would be crucial to keeping the XJ's suspension happy.

Another contribution to the build was a set of extended bump stops (PN KJ09114BK and KJ09122BK), courtesy of Daystar. These bump stops would allow our shocks to cycle comfortably without worries of having them bottom out too early, and were designed to fit right into the original XJ housings.

Daystar’s Kelly Herring had this to say: “Our polyurethane bump stops offer greater strength and rigidity over the stock bump stops. Polyurethane retains its shape better than the stock foam rubber, and will provide positive engagement for far longer. It’s great for vehicles like Project XtremeJ that will see a lot of off-roading and maxing out the suspension.”

Last but not least, for the wheels and tires we went with 17-inch Dirty Life Dual Tek 9304 DT-2s (PN 9304-7973MB12) and 35-inch Dick Cepek Trail Country EXPs (PN 74752). The wheels affect the look of beadlocks and give users a radical appearance to be proud of. Meanwhile, the tires have the chops to take on off-roading and keep the vehicle moving forward in the roughest terrain.

For footwear, we went with Dirty Life Dual Tek 9304 DT-2 wheels and 35-inch Dick Cepek Trail Country EXP tires.

The 9304 DT-2 is a functional beadlock wheel that will give our Jeep the ability to air down for going over rough terrain. It’s able to put up with a lot of abuse, as Joe Podlovits, VP of Marketing for Dirty Life’s parent company, Wheel Group, explained. “We perform a wide variety of tests along with constant quality control on all of our wheels,” he said. “On our Dual Tek series, we tested in both the standard and beadlocked mounting methods to ensure the wheels hold up under virtually any use.”

As for the tires, Dick Cepek’s product development team member Ben Anderson gave us the drilldown. “The Trail Country EXP offers benefits found in both mud-terrain and all-terrain tires,” he said. “The tread-to-void ratio is similar to an all-terrain, but the tread elements are larger and fewer in number, so the voids are larger, making it easier to clear out mud and keep up the grip.”

Installation Begins

For this install, we partnered with P&T Auto Services Specialty here in Murrieta, California. The expert team there, led by James, took charge on fixing up the Jeep and did a stellar job.

With the Jeep on the lift, we took some time to assemble the parts underneath and see the work that lay ahead of us – axles, shocks, steering, sway bars, and more. The Jeep was going to be a fixture at P&T Auto for the next few days, but the team there knew how to take care of this project, and did it with gusto.

James located the ABS wiring under the rear seat and uncoupled it.

Since the Jeep was sans tires and wheels and lifted in the air, we started disassembling the drivetrain. James removed the hardware holding in the driveshafts and let the axles droop slightly. Next, he took apart the ABS sensors on each of the brakes, and undid the brake lines.

On the rear axle, James unbolted the shock absorbers and then unbolted the U-bolts holding the axles to the leaf springs. The emergency brake cables were disassembled and placed to the side. Once the bolt holding the emergency brake bracket to the pumpkin was removed, the axle was now free and clear to drop down. James used an engine crane to do this.

After taking off shocks, U-bolts, driveshaft, brake lines, and other odds and ends, the rear axle was ready to come out.

We moved to the front of the Jeep now. James removed the sway bar cover and took out the sway bar mounts, letting the sway bar droop and making it easier to remove the end links. James undid the bolt holding the pitman arm to the drag link. He then went after the track bar, removing the bolt holding it to the upper mount.

Over on the axle, the driveshaft and control arms were next. James used swivel sockets to get after these and other bolts in hard-to-reach places. The ability to put high torque in low-clearance spots was a huge time-saver.

To get the front axle down, James used the right tools at the right time. Using a swivel socket on the control arms made unbolting them a breeze. After knocking out all of the components and wiring, the front axle was good to drop out.

James took off the brake components on the front axle and crimped the brake lines to prevent fluid from seeping out. He also removed the shocks from their bottom mount, and now the axle was ready to drop out.

Carrying On

Now that the old drivetrain was gone, it was time to start getting the new Currie axles ready. On the rearend, James bored out the axle’s alignment holes for the leaf springs, and then raised the axle to mock it up. Satisfied, he secured it in place with U-bolts and moved onto the front end.

Through a series of unfortunate events, we had to buy some new control arms from Skyjacker. James the got the new front end mounted and moved onto installing the new Bilstein shocks. These required some bracketry and welding to the axle, but they were well worth it.

After welding in bottom mounts, James installs the new Bilstein 5160 shocks to the front axle.

James removed the old pitman arm and installed the new one.

James moved onto the pitman arm. He used an air wrench to jerk the nut loose. It couldn’t fight against so much pressure and torque, coming off after just a few seconds. He fixed on a pitman arm puller and pulled the pitman arm off using a regular wrench, and that was that.

The new pitman arm was from a right-hand-drive JK, which moved the mounting point of the drag link out to match the extra width of the JK steering. James attached the drag link from the steering arm to the pitman arm, and lowered the vehicle down from the lift. He installed all four tires, and got in the driver’s seat. He wanted to make sure the drag link and steering arm were going to be friends going from lock to lock; otherwise, there would be death wobble.

After installing the drop bracket for the steering pump, James checked the angles and clearances of the front end. In the end, everything worked out perfectly.

As it turned out, everything was copacetic with the steering setup, and the wheels turned left and right without issue. James wrapped up the steering by installing a drop bracket for the steering pump, and moved on.

Halfway There

James made new brackets for the emergency brake, first by grinding off paint and then by welding on said brackets.

We made it past the halfway point now with our axles, steering parts, and shock absorbers installed. James lifted up the Cherokee once again and went to the rearend, where he used a grinding wheel to make mounts for the new e-brake brackets.

Next, James went and measured the lengths of line and sleeve needed to route the e-brake. He took part of the old factory linkage and repurposed it to work with the new brake lines and sleeves. While this was going on, a technician from Inland Empire Driveline came by to take measurements for the driveshafts.

James put together the emergency brake using new cable, sleeves, and a repurposed stock linkage. Meanwhile, a technician from Inland Empire Driveline came by to measure the lengths of the new driveshafts.

James caught a breather outside of the Jeep’s undercarriage to work on the E-Locker wiring on the front axle. He went inside the Jeep and removed the center console bezel. There was an open button slot that would be a perfect place to mount the new switch. However, it would have to be carved out and carefully at that, making sure not to shred the mounts on the adjacent switches.

Wiring up the E-Locker on the front axle meant making a new home for the switch, as well as running wire down the control arm. James used zip-ties to secure the wiring to the control arm.

With that done, James ran the wiring through the dashboard, out of the firewall, and down onto the driver’s side control arm. He popped off the differential cover to access the plug to the locker, and connected the switch and locker together. After testing and hearing the locker engage, James used zip-ties to secure the wire as it trailed up from the control arm and into the engine bay.

The front axle still needed some things taken care of, however. Two of these were the limit straps. These were essential for the lifted and linked front end, which would droop too far without them. James made holes in the shock mounts on the axle and shock tower in the fender, and slid bolts through to secure the straps in place.

To get the front driveshaft to work, James cut up the exhaust and welded on a four-inch piece of tubing. This made the system clear enough of a gap to allow the driveshaft to go in.

Wrapping Up

The front end got more attention as the job got close to the end. Here, James installed limit straps and the Daystar bump stops. He also cut out the metal brackets, giving the Currie Anti-Rock sway bar free range of motion.

Nearing the end of the installation, we received the new driveshafts from Inland Empire Driveline after about three days. However, we weren’t out of the woods yet. James discovered that the stock exhaust was in the way of the front driveshaft’s travel arc, so some fabrication was in order. He welded up a piece of tubing that created enough clearance for the driveshaft.

James moved onto the front sway bar, now a Currie Anti-Rock sway bar system. Designed as a kit that allows high cycling of the suspension without sacrificing body roll characteristics, its travel arc required fabrication (read: cutting), just like the exhaust system. A V-shaped piece of metal on either side of the frame got in the way of the arc, so James hit the pieces with a sawzall blade. After attaching the end links to the axle, the sway bar was installed.

James and a fellow technician went around the Jeep, bleeding the brakes.

We neared the home stretch now. James installed the front bump stops, provided by Daystar. Their added length would help the suspension from bottoming out on harsh terrain. James also seated the springs into place, and then popped the hood to start bleeding the brakes. Pouring fluid in as needed and working with a fellow technician, the duo took only a few minutes to bleed the entire system.

All that was left now was bolting up the tires and wheels, which looked absolutely killer. You can expect to read our full review on them soon, but just know that they were ready to rock as soon as they touched the ground!

We couldn’t wait to test out Project XtremeJ!

The Shake Down

Now that Project XtremeJ was all set up, we took the blue SUV out for a joy ride. The spot we went to took us around the mountains of Southern California. It was a nice, hot summer day. It was perfect weather for stress-testing not just the vehicle, but our own willpower to keep going.

XtremeJ exhibited no shakiness or poor handling on the way to the trail. We’d taken the rig in for an alignment after the whole installation at P&T Auto, as we should, and were happy to enjoy a comfortable ride out to the dirt on the highways and side streets. From the Dick Cepek tires to the Bilstein shocks to the Omix-ADA suspension components, everything was working perfectly.

Project XtremeJ's running gear is now up to the challenge of go-anywhere, do-anything off-roading!

After a good 45 minutes of driving, we got to the trailhead. It led us up the side of a mountain on some nice little dirt paths. These were presumably fire roads that stretched on for miles around the area. We took the Jeep off-course more than a few times, just to see how far the Jeep could go. It quickly became apparent – the Jeep could go anywhere!

The locking differentials gave us the control to go up steep grades, while the tires took care of the rest. We had plenty of articulation even as we went up a rocky, slip-prone incline, thanks to the Anti-Rock sway bar. The Trail Country EXP tires did phenomenal as well, and you can look forward to a full review on those tires soon.

Project XtremeJ is now a stellar SUV capable of taking on just about any terrain it comes across. With more articulation, grip, and traction-locking ability, it’s undergone a total transformation from the lowly, average vehicle it once was. We’d like to thank Currie, Dick Cepek, Dirty Life, Bilstein, Daystar, Eaton, Omix-ADA, and all of the previous sponsors that made this project a reality. To catch up on more about Project XtremeJ, go check out the build page, and keep it locked here on Off Road Xtreme for more off-road awesomeness!

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About the author

David Chick

David Chick comes to us ready for adventure. With passions that span clean and fast Corvettes all the way to down and dirty off-road vehicles (just ask him about his dream Jurassic Park Explorer), David's eclectic tastes lend well to his multiple automotive writing passions.
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