Click for Coverage
Exclusive Content
Original Shows, Motorsports and Live Events
Try it free for 14 days
Due to the EU’s Global Data Protection Regulation, our website is currently unavailable to visitors from most European countries. We apologize for this inconvenience and encourage you to visit for the latest on new cars, car reviews and news, concept cars and auto show coverage, awards and much more.MOTORTREND.COM
  • JP Magazine
  • Dirt Sports + Off-Road
  • 4-Wheel & Off-Road
  • Four Wheeler

How-To: Jeep TJ Unlimited TeraFlex 4-inch Long-Arm Suspension Installation

Posted in How To: Suspension Brakes on May 29, 2018
Share this

TJ owners love the quick steering and excellent maneuverability of their short-wheelbase Jeeps in tight spaces, allowing them to easily dart in and out of crowded parking spaces in the ’burbs or weave through tight trails in the boonies. The ride and handling of these coil-sprung models, offered from 1997-2006, established a new era for Wranglers, and made them a highly sought-after model by those who preferred maneuverability over four doors.

The TJ’s coil-spring suspension also made it easier to maintain the ride and handling when it came time to slip taller tires underneath for greater ground clearance. This is exactly what a customer of Dunks Performance was looking for when he rolled into its shop in a 2006 TJ Unlimited Rubicon, or “LJ” as they are affectionately known. (The LJ’s wheelbase is 103 inches, 10 inches longer than the TJ.)

This particular LJ had been set up with a 4-inch lift when it was new. Now, more than a decade and 60,000 miles of on- and off-road miles later, it was overdue for an upgrade in suspension parts and technology. A lot of research led the customer to choose a 4-inch TeraFlex Enduro LCG Long Flexarm suspension system without shocks to continue using the Fox 2.0 remote-reservoir units he already had.

The Enduro kit incorporates long lower control arms made from heavy-duty, 1 3/4-inch DOM tubing for both front and rear, and new uppers for the rear while retaining the stock upper arms. The kit also includes the TeraFlex Belly Up skidplate to beef up protection without blocking access to the transfer case. The Rubicon model also required a new air compressor mounting plate that bolted to the Belly Up. When the kit is installed it gives the same ground clearance as one would get with more traditional 6-inch lifts.

We followed Casey Castle, the lead tech at Dunks, as he installed the kit from start to finish. The job isn’t for the faint of heart or the typical driveway DIYer. TeraFlex says installation time by a shop experienced with such suspension work takes 13 hours, with a couple of those spent cutting off the OE lower control arm brackets, grinding the frame, and welding on the new lower control arm brackets. The job also requires a front-end alignment, which was also handled at Dunks’ shop. Two days after rolling into the shop, this Rubicon LJ hit the street with state-of-the-art suspension capable of delivering many years of exceptional highway/off-road ride and handling.

Here is Dave Diens’ ’06 Wrangler LJ before the 12-year-old 4-inch lift was replaced by a modern TeraFlex Enduro LCG Long Flexarm system.
The TeraFlex suspension kit comes with well-illustrated instructions for every aspect of the installation, so there are very few questions that arise as to what goes where.
Dunks Performance’s lead fabricator, Casey Castle, stripped out the front steering, disconnected brake lines, and removed the control arms in preparation for dropping out the Rubicon LJ’s Dana 44 housing assembly.
Installation of the Enduro kit required lifting the engine enough to slide in 5/8-inch powdercoated spacers between the engine mounts and the frame pedestals that help align the driveshaft angles. We had to ream out the hole in the frame mount to get the shouldered alignment nut to fit.
There are many ways to remove the lower control arm mounting brackets. Castle’s preferred method is with a plasma cutter. He keeps the tip parallel to the frame and cuts downward through the factory welds so the frame itself isn’t damaged. It’s almost like running a fillet knife along a fish’s backbone.
After we’d removed the LJ’s front lower control arm mounts, the areas they were removed from were ground smooth in preparation for installing the new TeraFlex brackets.
Jp Pro Tip: Put heavy masking tape around all the shock shafts so they are not pitted or damaged by flying molten metal during the cutting, grinding, and welding on the frame rails.
The rear mounting brackets for the lower control arms are also removed. Note how the welds are cut with the flame of the arc pointing down and parallel with the frame rail. An air chisel or grinder can also be used, but it takes much less time with a plasma cutter.
TeraFlex provides a well-designed lower control arm bracket that wraps around the frame rail and is welded in place. Casey used a white marker to trace its outline for grinding where the welds will be located.
A couple minutes with the grinder was all that was needed to prep the frame. The cleaner the frame, the better the welds.
There are no measurements in the instructions for where the new mounting bracket plate is located other than rear bolt hole should be lined up with the rear mounting hole for the factory transfer case skidplate. We used the OE skidplate spacers and bolts to hold the bracket, and then positioned the bracket so the front end of the plate was 3 inches from the next hole in the bottom of the frame rail.
With the bracket in place, Casey welded it up. He made stitch welds along both sides, and then gave the area a good coating of rust-inhibiting paint while the area was still warm. The same steps were repeated on the passenger side.
The best way to install the TeraFlex rear control arms is to do one side while leaving the stock (or existing) control arms connected on the opposite side. This keeps the axlehousing in the proper location and connected to the vehicle, speeding up the installation process.
One of the items that makes TeraFlex’s heavy-duty flexarms different is they use 1/4-inch rod ends that are both greaseable and rebuildable. By relocating the lower control arm mounting point at the frame end, and utilizing the rubber Clevite bushings at that mounting point, road noise transferred through the frame is greatly reduced.
The curves in the rear lower control arms allow them to clear the frame under maximum suspension compression. They can also be adjusted without taking them loose from the vehicle, making alignment and driveshaft angle adjustments very easy. Our initial adjustment was 42 inches eye to eye.
TeraFlex uses “linear” coil springs instead of progressive-rate for optimum on- and off-road performance. The new springs are also larger in diameter than OE, and the rears are rated at 210 pounds—50 pounds more than factory to better handle aftermarket bumpers and accessories.
We retained the Fox 2.0 shocks that were part of the old 4-inch lift. This cut down on the cost of the TeraFlex kit and shocks that have continued to perform quite well over the years.
A neat item in the TeraFlex Enduro kit is this skidplate to protect the steering box. It requires drilling and tapping an extra hole in the front crossmember, but the little bit of labor this took was well worth the added protection.
The kit also comes with a new drop pitman arm. Castle torqued the nut to 185 lb-ft per specifications.
Having the Wrangler on a hoist made installing the TeraFlex front coils a breeze. The front coils are rated at 200 pounds, 50 more than the factory coils. The heavier springs are a nice match up for the added weight from the heavy-duty aftermarket winch bumper, Warn winch, and 34.5-inch mud-terrains on this LJ.
TeraFlex includes heavy-duty sway bar links with sway bar disconnect pins so they can be quickly disconnected and held in place when the real off-roading begins. We drilled and tapped the frame for the 3/8-inch stainless steel securing stud.
The Enduro LCG Suspension System uses the same lower control arms and brackets as the Pro LCG Suspension System, but it retains the factory upper control arm mounting points and the factory front upper control arms.
We retained the Fox 2.0 remote-reservoir front shocks that were already on this LJ, but replaced the old brake lines with the stainless ones included in the TeraFlex kit.
Jp Pro Tip: When you install the tie rod, connect the axle assembly end first, then do the pitman arm. Doing it the other way will create a lot of hassle trying to get the bolt to line up with the mounting hole.
The heavy-duty TeraFlex Belly Up skidplate adds another 2 inches of ground clearance under the transfer case and substantially more protection to the underbelly. The new skidplate also negates having to hack up the factory skidplate and allows full travel of the longer lower control arms.
On this long-wheelbase-Rubicon TJ lift kit, TeraFlex includes a special skid/mounting plate for the solenoid assembly that controls the lockers in the Dana 44s.The mount bolts to the Belly Up skidplate.
When TeraFlex says its suspension kit is “fully inclusive and functional,” they mean it—right down to the brake line brackets that are on the rear upper control arms.
Richard MacFarland, the alignment specialist at Dunks Performance, adjusts the TeraFlex rear control arms so that the pinion angle is about 1 degree less than the driveshaft angle to prevent unwanted vibrations while driving on the highway.
The last step of the installation was the front-end alignment, which MacFarland easily handled using a laser alignment system one bay over from where the lift was installed.


Dunks Performance

Connect With Us

Newsletter Sign Up

Subscribe to the Magazine

Browse Articles By Vehicle

See Results