Last issue we set course toward bringing our ’05 Wrangler Unlimited up to par, and checked off a pretty big box on our to-do list by swapping our bent, under-geared, and 100 percent-open axle assemblies with a pair of brand-new G2 Dana 44 axles. In this installment we’ll make another leap in the right direction by trading our craptastic 4-inch short-arm suspension for a better-performing, longer-armed solution from Rubicon Express.
Rewinding a bit—since we saved our LJ from the junkyard vultures as an insurance-titled wreck with a twisted-up and broken suspension, an el-cheapo lift kit got the nod as the best temporary solution to buy us some time and get us out on the trail. It did its job, but like the guy who’s been told one too many times to keep his hands off the strippers, it’s time to show it the door. The end-all fix came in the way of a Rubicon Express 4.5-inch Extreme Duty suspension system. You really have to install one of these systems yourself to fully appreciate the overall engineering and added component beef, but we’ll do our best to illustrate it for you here.
Kangaroo, T-Rex, and short-arm TJ suspension systems all share one thing in common—they have awkwardly short and largely ineffective arms. As you keep lift heights in check (preferably under 4 inches), and you’re not straying dangerously far from factory suspension geometry, you’re generally in the clear. But add any 4-inch or taller lift on a short-arm TJ and you’re verging on the limitations of the arm’s geometry, almost certainly setting yourself up for a bone-jarring ride, terrible articulation, and borderline-dangerous handling. Instant death? No, probably not, but if your TJ gets used for more than topless jaunts down to the ice cream store, its off-road prowess will likely be akin to stepping on a fresh dog-turd while barefoot. We’ve been squishing the 4-inch short-arm system in our LJ between our toes for over a year now, and its deficits are starting to wear on us. Among other gripes, flex and overall suspension action is pretty unremarkable out on the trail. On-road it dealt out some pretty hairy bump steer, the occasional episode of death wobble (often at the most inopportune of times), and a ride-quality that’ll rattle your fillings and heighten your situational awareness of potholes. We have 1-ton trucks that beat us up less than this Jeep.
A long-arm kit creates a more ideal environment for your suspension to do its job, and the more horizontal the controls arms are, the more conducive the environment. Tying the control-arm pivot points into a more centralized location on the frame not only lowers the operating angle of the arms, but also means each control arm bushing is doing less work when the suspension cycles and allows the potential for more travel at the axles with less binding. Adding it all up, a long-arm system provides a much improved ride, better stability, increased traction, a substantial increase in travel and articulation and an overall higher level of safety both on and off road.
One of the features that sold us on the Rubicon Express system is the company’s optional Tri-Link rear upper arm assembly. The best part about checking the Tri-Link box is that it allows you to ditch the rear track bar, and opens the door to even better suspension action and handling characteristics. And like all of Rubicon’s suspension systems, it comes with a lifetime warranty. While you can certainly install a Rubicon Express long-arm kit on you garage floor, be prepared for some additional cutting and welding that normally aren’t associated with installing a short-arm system. To help document our install, we brought our Jeep back to the folks at Importech in Conway, New Hampshire, where talented techs, fabricators, and (despite their name) Jeep nuts all hang their hats. Next time we’ll be tying everything together with a few choice components, buttoning up loose ends, and taking our resurrected jalopy out on its maiden test ’n’ tune trail voyage.
Step By Step
1. With a jack under the transmission to support the driveline, zip-out the three bolts on both sides, and the four nuts in the center for the trans-mount, the factory T-case skidplate was ready to part ways with the Jeep. Since this kit requires that you either buy or make a high-clearance after-cat exhaust, this will be your most convenient time to yank out the muffler and tailpipe.
2. At the core of the Extreme Duty Long-Arm system is this well-engineered and super-stout crossmember. Comprised of five main pieces, this crossmember will now pull double duty as both driveline support and mount for the lower control arms. When fully installed, the center portion can be easily unbolted to service the transmission and/or T-case, which is a feature we’ll be taking advantage of when we go to install the slip yoke eliminator.
3. With a couple of bolts on either side attaching the center to the outer control arm mounts, we temporarily bolted the crossmember assembly to the factory holes to verify proper fitment and to mark the four 1-inch holes that need to be drilled in the underside of the framerails. These holes provide clearance for the nut inserts on the backsides of the control arm mounts, which in turn allow installation of the side plate reinforcements installed in the next step.
4. With the crossmember assembly lowered back down and pilot-holes drilled in the four marks we just made, it was time to break out the 1-inch hole saw and start hogging out the holes to their final dimension. It helps to have a spare set of hands to spray lubricant on the bit as you work your way through the frame. It’s not a difficult step, but it is a filthy one—make sure to wear safety glasses. Only the bottom sides get drilled here.
5. With the side support plates bolted onto the crossmember and the entire assembly bolted snugly to the framerails, we used a locating punch to mark the three holes on either side for drilling and installation of the thick-walled steel frame inserts.
6. After drilling the outer face of the frame with the same 1-inch hole saw in order to slip the steel frame spacers in place we drilled a 1/2-inch hole through the backside to run a 1/2-inch bolt all the way through. Then the inserts can be welded to the outside of the frame.
7. The last steps in prepping the frame for the new crossmember is grinding the weld beads flush and painting any bare metal. We used self-etching primer, followed by a couple of coats of flat-black enamel for a good color-match. As soon as it dried, the crossmember was bolted in place for the last time.
8. In order for the new lower control arms to have a full range of travel, all four of the factory stamped lower control arm frame mounts must be removed. With the new long arms holding the axle in place, we first scored the welds on either side of the mount with a cutoff wheel.
9. Next, we cut through the enclosed face of the mount with a plasma-cutter to create two separate halves (a cutoff wheel will accomplish the same goal). Finally, we tightened up each half into the jaws of a large adjustable wrench and simply bent them back and forth until they broke free from the frame.
10. Once you’ve reached this point, the only remaining steps are to grind the factory welds smooth and paint any bare metal. This process took a whole lot less time than we anticipated—which is a good thing, considering we had three of ’em left to do.
11. You need to adjust all eight of the control arms to the lengths specified in the install instructions. Rubicon uses its super-durable and fully-serviceable Super-Flex joint on the axle ends, and its shock-absorbing PTMEG Super-Ride bushings on the frame end. With this arrangement, you’ll have the misalignment needed to let the axles articulate at will, and up top, the cushion and handling characteristics for a civilized ride.
12. To illustrate some of the differences between our short- and long-arm suspensions with virtually identical lift-heights, here’s a quick ’n’ dirty comparison of the two. The most striking contrasts are the attachment points of the lower control arms and the angle that the arms are traveling at full-droop.
13. Also note the angles of the coil springs and shocks; with the long-arm they’re both still sitting on a perfectly vertical plane with respect to their mounting points. Not so much with the short-arm.
14. With the old springs removed, don’t forget to run a 5⁄16-inch drill bit through the center of the spring-pad for installation of the included 2-inch bumpstop spacers. One of the great things about a Rubicon Express system is that you’re able to forego the process of scouring the inter-web in search of all the knick knacks you’ll need to complete your install. The Extreme-Duty kit includes everything you’ll need as far as suspension and steering are concerned.
15. With the new 4.5-inch-lift springs, specially valved mono-tube shocks, and extended braided stainless brake lines installed, we bolted the front upper control arms to their respective mounts. Every control-arm bushing in the in the Extreme-Duty kit is greaseable.
16. Since the design and amount of drop was similar, we initially planned on retaining the track bar drop bracket we installed with the el-cheapo lift kit, but once we realized that the Rubicon part used 100 percent thicker construction, swapping it out was a no-brainer. This is a process that would normally be a drill and bolt-on proposition, but instead of drilling two more large holes within close proximity to the steering box mount, we opted to weld it on instead.
17. Along with drilling out the factory upper track bar mounting location to 5⁄8-inch, you’ll also need to open up the front and back of lower mount with a 1/2-inch bit to provide clearance for the larger 1/2-inch-diameter bolt used. Rubicon Express offers its twin-tube steering stabilizer that would’ve likely been an improvement, but we kept our existing single stabilizer.
18. Rubicon states that the included drop track bar was designed around the 5.5-inch system and trimming the threaded end of the track bar may be necessary for axle alignment. Indeed it was, and before we put the Jeep up on the alignment rack we’ll have to lop off about 3⁄8-inch of thread to get the axle perfectly centered. Also, Rubicon includes a pretty killer set of front swaybar disconnects, but since we’re already using a Currie Anti Rock, we skipped this part of the install.
19. Rubicon’s Extreme-Duty long-arm systems come in two different flavors: the standard four-link rear or with the Tri-Link rear-upper assembly shown here. The Tri-Link utilizes a stout compilation of grey powder-coated brackets to create a truss over the axle’s centersection, and a massive “Builder Ball” joint sandwiched up top to make the connection to the upper control arms. Quality, over-built components continually impressed us throughout the install.
20. Instead of utilizing the built-in four-link upper arm mounts on the crossmember, the Tri-Link option comes with its own frame-side mounts since its arms don’t need to span the same distance. These mounts come with supplied hardware if you want to drill and bolt them on, but we opted to burn them into place.
21. Although not necessary, we completely removed our new G2 Dana 44 rear axle to bolt on the new Tri-Link truss so we could snap a decent pic of it. The truss uses the three top-most diff cover holes in the centersection, as well as the factory upper control arm mounts (after drilling an addition hole in each) for installation. Also shown installed are the extended rear sway-bar links and bump stop spacers—the latter of which we chose to bolt to the axle’s pre-threaded spring pad, instead of sandwiched with the factory bumpstop up top.
22. With the new upper mounts wearing a fresh coat of paint, and all the rear arms loosely hung from the tree with joy, we were ready to hoist our axle back up into place and put the rear portion of this install in the bag. Since a slip yoke eliminator and longer rear driveshaft come highly recommended (we’ll tackle these and other related components in the next installment), the adjustable front and rear upper-arms will make it a snap to dial in proper caster and/or pinion angles.
23. Ta-da, done! Well, almost. We still need to torque all the bolts to spec with Jeep planted on the ground, and there are still a few loose ends to address. This system comes with a rear extended, braided stainless steel brake line, but before we plumb it in we want to weave a couple new axle hard brake-lines neatly in and around the Tri-Link Truss. Stay tuned for Part 3 where we tie together the driveline with new driveshafts, toss in a slip-yoke eliminator, install an exhaust and swap the 33s for a more appropriate 35-inch size.