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TNT Customs’ TJ and LJ Long-Arm Lift Kit

Posted in How To: Tech Qa on October 21, 2015
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We bought our first Jeep (a ’46 CJ-2A) from my wife’s father in 1964 and there have been many more since, so we have quite a few decades of experience with Jeeps. When it was time to get our new-to-us Jeep, we decided to go with a first-gen Wrangler because, while it has many of the creature comforts we both desired, it has few of the electronic nannies I can live without. So when I located a fairly basic used Rubicon Unlimited LJ in Manchester, New Hampshire, our youngest son and I flew out to pick it up and drive it back to Arizona. We set the cruise control, turned the radio up, and steered the Jeep between fuel and food stops. That 3,000-mile trip, at those sustained high speeds across most of the United States, proved the reliability of the 10-year-old Wrangler.

Uplifting Moment
When it came time to begin the transmogrification of the stock LJ, we decided to go with TNT Customs suspension lift kit. Talking to the folks at TNT, we found out that the TRI-4 rear suspension was designed to cycle vertically throughout articulation to eliminate rear-steer commonly found in other suspensions. The lower arms are manufactured from 2-inch, 0.375-wall 1026 DOM tubing to handle anything they may come in contact with. Upper arms are 1.50-inch by 0.250-inch 1026 DOM tubing. All control arms have 2 1/2 inches of adjustable length and feature rebuild-able Flex joints and bushings.

TNT Customs works with shock absorber and spring manufacturers such as FOX and ARB to create its suspension system. TNT recommends the FOX 2.0 Performance Series IFP smooth body shocks because they offer a comfortable on-road ride and predictable off-road handling. The Old Man Emu coil springs (2989 front springs and 2949 rear springs) from ARB are a perfect match for these shocks and the LJ. While the LJ’s Rock-Tek Y-link high clearance front arms are similar, albeit much stronger, to the Jeep’s OEM suspension, changing the rear suspension from a track bar system to a Rock-Tek dual-triangulated four-link, along with relocating the shock mounts helps to improve the overall stability of the Jeep. A big difference between this kit and others is there are no anti-sway bars to worry about disconnecting in this system.

The kit’s high-clearance pan nets a clearance gain of 1 3/4-inch over stock on ’97-’02 models and nearly 3 inches on ’03-’06 model years. TNT Rock-Tek long arm suspension kits also come with a weld-on, full-length rear axle truss assembly for the rear axle. It includes the TNT Tri-4 mount, coil-spring mounts, new lower control arm mounts, and shock mounts.

This kit is not for the faint of heart. It’s not a simple bolt-on assembly, and unless you’re a very experienced mechanic with a full complement of shop tools, including a plasma cutter, MIG welder, grinders, air tools, drill press, power saws, floor jacks, and a chest full of hand tools, you should really consider having a pro do the work. We did just that.

Rims and Rubber
One of the primary reasons to get a suspension lift system is to get more clearance for the axles with some bigger tires. We went with the Yokohama Geolandar M/T 35x12.50-17 directional tires because they will help us churn through mud with their beefy tread lugs and deep voids. In case your Jeep can’t fit 35-inch tires, the M/T directional tires are available in several different sizes, from 29 to 40 inches in diameter.

Big meats have to be mounted on wheels strong enough to support them and attractive enough to complement them. We liked the Raceline beadlock and got them through Summit Racing. These wheels are engineered to hold up to the extreme abuses of off-road desert racing and professional rockcrawling. They offer a 32-bolt beadlock system built with durable outer rings and a strong inner lip to allow your rig to go over obstacles, while keeping the tire bead securely attached to the wheel, even at very low air pressures.

One Direction
A sturdy steering system upgrade is also something that should accompany a suspension lift system and larger tires. We turned to Rugged Ridge for its heavy-duty steering components (replacing the OEM tie rod with a stronger straight tie rod) and stabilizer. Once the install was finished, the LJ went to the closest Ted Wiens Tire & Auto for a full chassis alignment. A full chassis alignment should be done after any suspension rebuild, and the Ted Wiens shops have the requisite experience with 4x4s.

The TNT front truss is an option and is not included in the kit. TNT indicated that the front truss is not absolutely necessary, but we opted for it because of the added strength to the Dana 44 housing and the fact that we may go to larger tires than the 35s we’re mounting now. The TNT front truss is made from 3/16-inch steel and greatly increases the housing’s strength.
All factory attachment points must be removed from the front axlehousing in order to mount the truss. We used a grinder to clean them off of the front axle and smooth out all the surfaces.
We double-checked all our measurements to verify that the truss was properly aligned prior to welding it into place on the front axle. The truss must be in just the right location so that the pinion angle will be within acceptable working parameters.
When all the OEM attachment points had been removed, we located the rear truss, tacked it into place, and verified its location under the Jeep. We then pulled the rear differential back out, turned it upside down, and finished all the welding on the truss.
Before mounting the TNT cross members, the engine had to be lifted an inch. That lift was accomplished by swapping in a pair of Mountain Off-Road Enterprises motor mounts. The Jeep’s 4.0L exhaust also had to be modified for the TNT Customs crossmembers.
The Jeep’s body also had to be lifted an inch for the TNT Customs suspension, so that was our next task. We cut off the OEM body mounts so the TNT-supplied body mounts could be installed where called for in the instructions.
In order to remove the front driveshaft, the front crossmember/skidplate must be removed. With the Rubicon model, the air pumps for both axle lockers are mounted on that crossmember. Once the transmission and mount were secured to the replacement crossmember, we fabricated a new mount for the air pumps.
The OEM control arm mounts on the Jeep’s frame rails must be removed before the TNT crossmembers can be mounted.
Just as we did with the front axle, adjustable straps were used to hold and position the rear axle in place underneath the Jeep. This allowed us to fine-tune the position of the axlehousing while bolting all of the Y-link components into place.
After cutting out a portion of the frame rail, the upper shock mount must be welded on the sides, top, bottom, and across the slot to make sure the frame is not weakened.
We discovered that it is much easier to install the Rusty’s Off-Road adjustable upper spring pads first. We removed the foam bump stop and the bump stop cup. A plasma cutter, hammer and chisel, air chisel, and a grinder were used to remove the OEM upper spring pads. Once the sides of both frame rails are smooth, you can fit the kit’s bases onto the frame. The base’s go in the peak of the frame rail’s upper curve.
The coil springs were then slid into place. On this Jeep, the lower bumpstop can’t be screwed into place until the spring is located. Use a Philips screwdriver to thread and tighten the bump stop into place. The ARB rear coil springs come in two lengths, and the shorter one goes on the driver side. Everything was bolted back into place, and the Jeep was ready for its tires.
This is an example on how the finished rear four-link system should appear. Also make sure that your new exhaust system completely exits the rear of the Jeep.
The Raceline Allied brand steel beadlock wheels we got from Summit Racing are 17x10s with a 3 1/2-inch offset, which is an excellent match for the Yokohama Geolander M/T 35x12.50-17 tires. Each rim bolt must be torqued according to the manufacturer’s specifications and sequence. Tires are on, limiting straps in place, and the Jeep is ready to go.
The Rugged Ridge heavy-duty steering kit included much stronger tie rod ends and clamps. The stronger design gives you a straight tie rod—instead of a curved tie rod—with the drop link attachment point near the end. A new steering shaft support was also included in the kit with the body lift. We used the heavy-duty stabilizer kit from Rugged Ridge.
After the suspension and steering modifications were complete, the Jeep was ready for a complete chassis alignment. This is something that should be done after any suspension kit installation and before the Jeep gets driven very far. Ted Wiens Tires in Las Vegas, Nevada, took care of this chore for us.
With the TNT Customs lift and body armor in place, the ’05 Unlimited Rubicon was a much more capable trail vehicle and easily able to scale a 6-foot-high near-vertical waterfall.
PhotosView Slideshow

Sources

Summit Racing
Akron, OH
800-230-3030
http://www.summitracing.com
GenRight Off-Road
Simi Valley, CA 93063
805-584-8635
www.genright.com
Rugged Ridge
www.ruggedridge.com
TnT Customs
Cheyenee, WY 82007
307-775-9565
www.tntcustoms.com
Rusty's Off Road
256-442-0607
http://www.rustysoffroad.com
ARB
866-293-9078
www.arbusa.com
TeraFlex Suspensions
www.teraflex.biz
Yokohama Tires
Fullerton, CA 92631-5106
Fox
800-369-7469
http://www.ridefox.com
Ted Wiens Tire & Auto
http://www.tedwiens.com/

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