This just might be too revolutionary for some of you. You leaf-sprung Jeep guys might not want more flexibility out of your suspension. And you probably don't want to lose more than half of your spring weight. And who the heck would want orbital eyes in place of bushings for improved suspension movement? Yeah, our YJ owner was pretty skeptical too. We almost had to bribe him to throw on Teraflex's new fiberglass single-leaf spring wonders for YJ Wranglers. He complained that they weren't going to flex, and that they would probably shatter once he hit some rocks with 'em. But now that he's tried 'em out on the Rubicon Trail, we haven't been able to get them back from him. It's no wonder; he's seen the light, or should we say the superlight.
Teraflex has them available for a YJ Wrangler right now. You can get a complete kit to convert a bone-stock YJ to the supreme rock commander, or as a spring-only kit to retrofit already-built YJs. We took our rockcrawling Wrangler and did a quick spring swap in almost no time at all.
One of the coolest features of the new Fiberflex monoleaf springs from Teraflex has to be the orbital-eye ends. They will give a little rougher ride on the highway and transmit more vibration than a conventional urethane or rubber bushing, but the additional suspension movement is worth it. | 
The Fiberflex springs are dimensionally the same front and rear, and all four have the same single spring rate. The monoleaf springs weigh 13.8 pounds each, quite impressive when compared to the 35.4-pound steel leaf springs they're replacing. | 
If you're starting with a bone-stock Wrangler, Teraflex has this complete kit to fully outfit your YJ. It comes complete with the springs, the spring-over axle perches, high-steer kit, knuckle, shackles, and shocks. You even get Teraflex's new S/T disconnect sway bar. |
It's a little weird when putting the leaf springs in. We simply supported the vehicle and axle with the leaf spring in a neutral position, unbolted it, and heaved it out. Then we took three fingers and grabbed a Fiberflex spring and set it in with one hand, holding the front of the spring. Too easy. | 
The springs are offered as stock-height Wrangler spring replacements. Teraflex figured out that most YJ guys do a spring-over-axle swap and use the factory springs. If you need a bit more height, you might try a small (1-inch or less) block that ties itself to the monoleaf via the centerpin. You could also use longer shackles, but be aware that shackles will affect pinion angle. | 
It takes a little getting used to, but you'll like how much less mass there is in between your axles and your frame. The Fiberflex monoleaves fit directly in place of the factory leaves, but you'll need new U-bolts (because you're supposed to replace 'em anyways, and because the monoleaf is so much thinner than the four- or five-leaf steel spring packs). |
Off-Road Impressions
Our test vehicle was already built with 1 1/2-inch-lift steel leaf springs, so we knew we'd be dropping some height. We took measurements and found that we'd only lost 3/4 inch in height, putting these fiberglass springs at about 3/4 inch taller than stock springs. They won't settle too much since they are fiberglass and not steel, so we'd guess this is what you'll see even after months of usage.
We sent our tester on his merry way with a mission. "Go pound on these springs for a while and tell us how they work. Oh yeah, and see if you can snap one." You should see the smile people get on their faces when they're told to actually try and destroy something.
Our test Wrangler headed out with the Wine Country Rock Crawlers for the Rubicon Trail to see if he could do some damage to its new suspension. Four days had passed when we got a phone call from a sort of bewildered tester. He'd noticed the harsher ride from the orbital eyes instead of bushings and had automatically thought he'd be in for a rough weekend on the 'Con, but he reported he could twist the heck out of 'em. The monoleaves gave more movement than his steel leaf springs ever did-so much so that he is having to do some more fender trimming just to get his 36-inch Iroks to fit at full stuff.
He'd also given them a sufficient rock beating, dropping the Jeep's monoleaves directly onto rocks, and using them as ramps onto boulders. The only thing that peeled or split was the textured paint on the fiberglass spring.
The monoleaves passed a severe-beating test that would've snapped some leaf springs, and handled it with more flex and less axlewrap. Maybe you should try a set too.