We've been happy wheeling our stock-suspension '89 YJ with two exceptions.
First, the front end really sank once we added almost 90lbs of winch and winch mount to the front. Second, the stock front springs only offered a few inches of uptravel before hitting the bumpstops. That made for some miserable long-distance driving when scooting down miles of unimproved dirt roads to get to our favorite desert wheeling spots.
So, unlike most Jeep owners, when we started eyeballing new suspension systems for our little YJ, our main goal wasn't to fit bigger tires. We were after an improved off-road ride, more wheel travel, and increased load-carrying capacity. We've always considered the Rubicon Express Extreme-Duty systems to be among the finest mass-produced suspensions for a leaf-sprung Jeep. So, we dutifully ordered up the company's 2.5-inch Extreme-Duty Suspension System for our YJ, only to be told, "uh, that's cool guys, but we don't make those springs anymore." Us: "But you make 'em in the 4.5-inch version." Them: "Yeah, but we sell a lot of those. We still have the Standard-Duty 2.5-inch lift springs." Us: "What's the difference?" Them: "Well, after a couple years of hard trail use you may notice some settling." Us: "Is that all? Send 'em."
In the end, we ordered Rubicon's PN RE5530 Extreme-Duty 2.5-inch YJ suspension with four substituted PN 1430 Standard-Duty 2.5-inch lift springs, four of its PN 2050 spring-under U-bolt plates, and the company's PN RXJ505 front and PN RXJ506 rear monotube shocks. At present, we've only done some light wheeling and a couple hundred street miles on the new suspension, but we'll be flogging this sucker in the coming months. Check out some install highlights this time and tune in for some more in-depth driving impressions next month.
By the Numbers
We thought to break out the tape measurer to see how much lift the new Rubicon Express springs netted us from the bottom of the front and rear bumpers to the ground. After a couple hundred driving miles and a few twisty off-road trails, we took our after numbers. Keep in mind our '89 YJ is a bantam-weight, with a four-cylinder engine, no carpet or extras, and only a 15-gallon fuel tank. Heavier vehicles will realize less lift height.
| | Front (in) | Rear (in) |
| After Lift | 22 7/8 | 21 1/2 |
| Before Lift | 18 1/2 | 18 1/4 |
| Total Lift | 4 3/8 | 3 1/4 |
Aside from the springs, the...
Aside from the springs, the main differences between the Rubicon Express Extreme-Duty and Standard-Duty systems are the 5-inch long front and rear shackles (rears are boomerang), replacement braided steel brake lines as opposed to hard line extensions, and the included poly shackle bushings and greasable shackle and spring eye bolts. Otherwise, both include a T-case lowering kit, track bar relocation bracket, U-bolts, lengthened swaybar disconnects, and everything else you see here minus the shocks and U-bolt plates.
The Rubicon Express 2.5-inch...
The Rubicon Express 2.5-inch Standard-Duty springs, PN 1430 feature many of the same niceties as the now-discontinued Extreme-Duty packs, like military wrap main eyes, half wraps shackle eyes, U-bolt clamps, and Teflon friction pads between leaves. We started the installation by greasing the poly bushings and inserting them into the spring eyes.
We always begin on the front...
We always begin on the front since it's usually the most complex. After chocking the rear tires, set the Jeep on jackstands tall enough to allow the front suspension to droop fully. We installed the longer braided steel brake lines and then, with a floor jack under the axle, removed the axle U-bolts and spring shackle and main eye bolts. Only work one side at a time so the axle stays located under the vehicle.
The spring hangers tend to...
The spring hangers tend to get bent inward when the factory guns down the spring main eye bolts. Use an adjustable wrench to gently open up the spring mount to allow the slightly fatter poly spacers in the new springs to slide in. Some slight persuasion with a dead-blow hammer is usual, but you shouldn't need to kill the spring eye with a hammer to get the new spring into position.
Unlike older CJs that use...
Unlike older CJs that use one-piece frame-to-shackle bushing inside a pressed-in steel sleeve, YJs use a two-piece rubber bushing setup that is easily removed. Knock out the steel insert with a drift and use the hooked end of a prybar to remove the rubber bushing halves. Then, lube the new poly bushings and tap them in.
The actual spring install...
The actual spring install is easy if you begin at the main eye. Jack the axle up enough that it won't contact the new spring and insert the main eye bolt. Then, insert the shackle bolts before lowering the axle down onto the spring centerpin. Snug them down, but don't fully tighten the shackle or main eye bolts until the weight of the vehicle is resting on the springs.
The Rubicon Express spring...
The Rubicon Express spring U-bolt plates, PN 2050 are beefy things made from 3/16-inch steel and protect the bottom of the axle U-bolts and nuts from trail damage. They fit the front just like factory, not interfering with any components. We don't run a swaybar on this Jeep, but the spring plates come with new threaded mounts, which can be inserted if needed to relocate the shock or swaybar mounts to the spring plates.
Moving to the rear, you can...
Moving to the rear, you can see how the Rubicon Express U-bolt plates interfere with the factory lower shock mount. We installed the new shock mount to the spring plate to relocate it to the spring plate. Other than this little fact, the rear installation goes down just like the front.
Rubicon's 5-inch shackles...
Rubicon's 5-inch shackles provide an additional 1/2-inch lift over the stock shackles and rotate the front and rear pinions slightly upward. The rear still requires shims to alleviate driveline angles, though. With the 1-inch drop T-case spacers and the supplied 2.5-degree rear shims, we were able to drive the YJ with the factory rear shaft, although we did have vibration when decelerating or coasting. We've ordered some of Rubicon's steel degree shims (available in 4-, 6-, and 8-degree increments) for when our CV rear driveshaft happens. Tune in for more info on that next time.
Once the weight of the vehicle...
Once the weight of the vehicle was on the springs, we torqued the U-bolts to 80lb-ft, the main eye bolts to 75lb-ft, and the shackle bolts to 65lb-ft. Notice the stock steering setup. We'll be changing it in a future issue, but even with a bit more lift than we were expecting (see By the Numbers sidebar), after adjusting the drag link to center the steering wheel we have experienced no ill effects from the lift using the stock pitman arm and no track bar relocation bracket at this lift height.