Jeep Wrangler TJ Lift - Engineered To The Nth Degree

The new front control arms feature a clearance-friendly bend like the rears, but are gusseted with a steel plate sporting a laser-cut Nth logo. This gusset ties into the upper control arm mounting points on the axle. Like other long-arm suspensions, the Nth kit does away with frame-mounted short upper control arms in favor of a both-arms-merge-into-one single-arm design. Unlike other kits, the Nth design features a bayonet-type bushing mount at the rear of the upper "arms" that allows for lots of "give" to tolerate the rotational bind created when a live axle is attached at four points and tries to articulate. The Nth design allows for movement and hence offers more articulation and longer bushing life. The "dog-leg" bend in the control arms not only offers increased ground clearance, but also allows full lock of the steering without any tire rub.

Monotube gas shocks with remote reservoirs from Rubicon Express were installed on the Unlimited. These shocks, or their non-remote cousins, are the recommended shocks that Nth offers to complement their suspensions. (Twin-tube shocks from Old Man Emu can also be specified for the 4.5-inch kit only.) Note also the included extra-long braided steel brake lines and coil-spring spacer. While using a coil spacer on top of a shorter coil spring may seem like a cheap move, it is actually more costly and there is a very important reason for doing it. Coil-spring design includes what's called a "slenderness ratio." This is the ratio of the spring's loaded height to its diameter. Make a spring with a ratio over 4:1 with a soft rate, and all it will want to do is buckle to the side when compressed. TJ springs are so small in diameter that a 4.5-inch-lift spring is at the 4:1 limit, so a 6-inch longer spring is out of the question unless you make the spring rate stiffer. Since a key part of Nth's suspension performance is the frequency-based tuning of the springs, the spring rate wasn't "negotiable" to the company. So a spacer is the solution. Spacers may not look as cool as super-long coils, but this setup works. As with the rear, the front bumpstops have been properly spaced to prevent shock bottoming and also keep the tires from mangling the fenders on those "Baja" whomps.

Last but not least are QuickSilvers. These are Nth Degree's front antisway bar disconnects. Jim insists that the stock antisway bars should be utilized on a TJ for optimal street performance. To that end, if you want great articulation, the 'bar must be disconnected for extreme 'wheeling. The QuickSilvers feature a cam-over design that requires no tools to operate and can be attached or detached without the vehicle being level. When detached, they fold up and lock themselves into special brackets mounted atop the spring perches-no bungee cords needed here. In the stored, disconnected position, both the links and the 'bar are out of the way of the tires at full lock when at full flex-no more rubbing!

Forty two inches. That's what we got when we raised the completed Unlimited up with a forklift with the front antisway bar disconnected and the rear attached ... and the tires at street pressure (28 psi). Forty two inches of obstacle crawling before another tire will lift off the ground. And yet this TJ drives down the highway better than any we've driven before, stock or modified. This kind of versatility was unheard of just a short time ago and shows just what can be done with the right engineering.

How's this for clearance? Rolling on 35s, the Unlimited measured 19 and 21 inches of ground clearance at every point under its chassis between its axles. Note how the control arms are tucked up almost inside the framerails all the way to the tires. It will be pretty hard to snag this Jeep on a rock via low-hanging suspension components.