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Rubicon Express Gives Jeeps Longer Legs - 2004 LJ Wrangler

Posted in How To: Suspension Brakes on June 24, 2016
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If there’s one area that we don’t mind spending a little money, it’s on a Jeep’s suspension. While the ’97-’06 Jeep TJ Wrangler and ’04-’06 Wrangler Unlimited (LJ) platforms benefited greatly from a well-engineered factory multi-link suspension system, the short control arm lengths quickly become the system’s downfall once taller coils are thrown into the mix. Spring rates, shocks, and the quality of the components all play a role in how the Jeep handles. However, for the most part, lifting a Wrangler more than 3 1/2 inches with factory length control arms is a recipe for less-than-ideal handling and performance on- and off-road.

When we purchased our ’04 Wrangler Unlimited, it was already modified with an overly tall short-arm lift kit. Between the worn steering components, sloppy suspension joints, and stiff coil springs, the Jeep was a wobbly mess. To get the LJ headed in the right direction, we decided to ditch to wonky short-arm suspension and move to a more refined means of travel with a long-arm suspension. These days, there are dozens of long-arm suspension options for the LJ, and each has its list of pros and cons.

We don’t plan on spending much time in the rocks with this Jeep, but rather general trail wheeling and daily driving. This cut out some of the more off-road–centric systems on the market and narrowed our path to a more conventional long-arm kit. In the end, we opted for a Rubicon Express Extreme Duty long arm. Rubicon Express was one of the pioneers of the mass-produced long-arm suspension system, and they have a great track record to show for it. With a mix of flex joints and bushings, the company’s long-arm suspension offerings are a fine balance of on-road refinement and off-road durability.

We opted for the 4 1/2-inch version of the kit for a few reasons. While running our goal tire of 35-inches with 3 1/2 inches of lift would be easily achievable, the extended length of the Unlimited platform tends to benefit from a slightly taller lift. Adding the extra height is mostly beneficial for the breakover angle of the 103-inch wheelbase. It’s also a good ratio of lift if we ever get the itch to run a 37-inch-tall tire.

To install the suspension system, we hauled our LJ to 4Wheel Parts in Raleigh, North Carolina. We’ve wrenched alongside the 4Wheel Parts guys in this store for years, and for some reason (it could be that we buy lunch), they keep letting us back in. While a driveway install of this kit is absolutely possible, it’s going to require a significant amount of drilling, cutting, and some welding. If your tool bin and skillset seem up to the task, we say go for it. We split our install into two days, which gave us plenty of time to install the lift, the necessary slip-yoke eliminator, and have a thorough alignment.

Since the Rubicon Express crossmember supports the transmission, as well as provides mounting points for the suspension links, it gets reinforcing via bolts on the bottoms and sides of the frame. With the transmission supported, we removed the factory crossmember and spent some time with a hole saw to open up the necessary points.

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The side holes receive sleeves, which require welding in place. Once the inserts are burnt in, you can add the crossmember support side brackets over the new bellypan rails.

Countersunk Allen-head bolts are used to secure the 1/4-inch-thick steel bellypan to the three-piece crossmember. We’ve used this same belly pan on previous Wrangler projects and have found it’s more than capable of supporting the weight of the Jeep on impact. The new bellypan has a slight lip pointing up at the front. On our LJ, you could barely slide a piece of paper between the top of the lip and the transmission pan. We decided to trim down the lip to create a bit more clearance.

Since we were doing away with the stubby control arms, we had to remove the stock lower control-arm brackets. An oxyacetylene torch and air hammer made this an easy job. A cutoff wheel or Sawzall are also effective means of getting the job done.

Speaking of control arms, Rubicon Express fit the new long arms with a mix of PT-Meg Super-Ride rubber bushings and Super-Flex joints. The new PT-Meg bushings are a significant step up from the Rubicon Express bushings of the past, while the rebuildable Super-Flex joints are a great mainstay in the company’s catalog.

Up front, the kit uses radius-style control arms. While not as free flowing as a three- or four-link setup, the radius arm is a great balance of on-road handling dynamics and off-road performance. For the amount of suspension travel and number of suspension joints used, the arms provided plenty of range of motion.

Out back, we opted for Rubicon Express’ four-link with track bar system (a tri-link is available as well). Every control arm is adjustable, which makes fine tuning the suspension much easier. If you are using a two-post lift, or have the Jeep suspended in the air by Jedi mind tricks, be sure to wait until the Jeep is resting with its weight on the tires before attaching the track bars.

As we mentioned earlier, our LJ had a short arm kit under it when we bought it. This meant the previous owner drilled out the frame for a track bar drop bracket. Of course, the new bracket didn’t line up with the old holes, so we broke out the MIG welder and fused the new dual-sheer track bar bracket to the frame.

Rubicon Express essentially makes the same track bar for its 3 1/2, 4 1/2, and 5 1/2-inch lift kits. This will require you to shave roughly 1 inch off of the male side of the bar when running the 4 1/2-inch version of the kit. We found a cutoff wheel made this process go by without a hitch.

For the rear track bar, we were in the same non-aligning bolt-hole trouble as the front. We burnt this bracket in place in addition to using the main bolt provided. The advantage of raising the rear track bar is to make the Jeep more stable. The adjustable rear bar also makes centering the rear an exact process.

While 4 1/2-inch lift coils raise the Jeep, braided steel brake lines and sway bar disconnects increase the performance attributes of the Jeep. For shocks, we installed Rubicon Express Twin-Tubes at all four corners. The 2-inch-body nitrogen-charged shocks are built with a 5/8-inch nitro-carbon rod and 1 3/8-inch banded piston. The shock’s valve tuning is also specific to the Wrangler platform.

Our only negative about this system is how low the rear control arms hang. Built from 2-inch/0.250-wall chromoly tubing, we have no doubt that the arms can take abuse. We will just have to be more calculated with our approach off-road, so not to tangle and drag the arms too frequently.

Despite having a longer wheelbase over the TJ, the LJ still benefits from a slip-yoke eliminator kit. We picked up this Mega Short Slip Yoke Eliminator Kit from Rugged Ridge. The Mega Short kit comes with everything you need and allows you to have an even longer driveline over conventional SYE kits. The longer the driveshaft, the less extreme the operating angle, which reduces the potential for driveline binding and vibration.

You can easily install the Rugged Ridge NP231 SYE with the T-case still installed in the Jeep, which will save you some time. Simply remove the back half of the case and reassemble with the new output. Aside from needing a good pair of snap ring pliers, this job is very straight forward and easy overall.

We called one of the East Coast’s premier driveline builders, Oliver’s Custom Drive Shaft, to get our Jeep rolling again quickly. Located in Winston-Salem, North Carolina, Oliver’s was able to get our new heavy-duty driveline to us the next day in Raleigh. Equipped with a 1310 double-Cardan joint at the transfer case and standard 1310 at the Dana 44, the 0.120-wall DOM tubing driveshaft came with genuine Spicer U-joints and thick slip splines.

To give the Jeep a balance of off-road traction and on-road grip, we went with Toyo Open Country Mud Terrain tires. Our 35x13.50R15 tire size provides an extra-wide footprint and a large set of siped and staggered lugs that reach well onto the sidewall. We’ve tested the Open Country Mud Terrain in the past and have been impressed with its on-road qualities and ability to grip the trail when off-road.

We’re big fans of beadlock wheels, so the Birddog wheel from Interco Tire was a great answer for those looking to air down off-road but needing something more conventional for everyday use. The 15x9 cast-aluminum wheel uses a high-set bead seat rib, which allows you to dabble in low-teens and single-digit air pressure territory safely off-road. With two valve stems per wheel, you can more easily deflate and monitor the outgoing air pressure as well.

Rubicon Express gives you control-arm length measurements that will get you pretty close, but we made sure that the Jeep was perfectly square and aligned on the rack. While we did have to make some exhaust system mods to clear the kit, the long-arm setup was complete.


Rubicon Express
Rancho Cordova, CA 95742
Toyo Tires
Interco Tire
Rayne, LA 70578
4Wheel Parts
Oliver’s Custom Drive Shaft

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