Springovers
By Grant

I get an awful lot of questions about doing a spring-over conversion on YJ's and CJ's; there are good reasons why. For most of us, it seems like some sort of black art. Everybody knows it's a matter of mounting the springs on top of the axle rather than beneath it, but how does one go about doing it? What are the advantages or pitfalls of doing a spring-over rather than a typical suspension lift? While nobody can write the complete manual for a spring over on each individuals vehicle, I'd like to at least help you decide whether you want to attempt the conversion or not. The advantages of a spring-over suspension are pretty obvious, one of which is cost. There's just not much enjoyment in blowing 300 dollars on aftermarket springs to achieve little more than the ability to run a larger tire. Relocating your existing springs will save you a good chunk of change and give you around 5 inches of lift. Both spring-over and traditional lift methods will require the typical corrections that go along with lifting a vehicle: longer shocks, dropped steering arm, extended brake lines, driveshaft mods, lowered bumpstops (assuming you'll be installing larger tires), etc. Since there is some unwritten code that aftermarket 4" Jeep lifts must be as stiff as your spine can stand, a spring-over is again attractive. By maintaining the use of the stock springs that have very little arch, you're assured the ride isn't going to be any worse (handling is an entirely different matter). Suspension travel is also greatly increased since you've moved the axle farther from the bumpstops; the stock springs can now travel in a much more broad range of motion. If there is a downside to this, it's possible that the stock springs will fatigue since they are flexing much more than the OEM designers ever intended. If this is the case, used stock springs aren't difficult to come by for use as replacements. The problem is in the details. First, performing the swap isn't for the timid. There is a fair amount of welding which must be precisely done, taking into consideration proper caster and driveshaft angles, not to mention the strength of the weld itself. You've got to have a way to accurately calculate and measure these angles before firing up the torch, otherwise, driveability will be affected, if it's still safely driveable at all. Another issue to address is the driveshafts themselves, particularly on YJ's and early CJ's. Lifting a Jeep 5+ inches with a driveshaft shorter than your arm is just begging for trouble. Severe vibration and/or complete U-joint bind will occur if nothing is done. For YJ's, as well as late CJ owners with a Dana 300 case, the problem can be greatly diminished by using a CV style rear driveshaft. For earlier CJ's, you're left with lowering the transfer case and purchasing a very expensive, custom built, reverse rotation rear axle assembly to ease the driveshaft angles. You can have a vibration free driveshaft after a spring-over conversion, but it's not going to be cheap. Probably the biggest threat to overall driveability after a spring-over conversion is the steering. By moving the axle and its steering linkage 5 inches away from the steering box, you've drastically changed the angle of the draglink. If unaddressed, this leaves you with some very scary bump steer. Even a lift as little as 2" will exhibit bump steer; 5" will leave you wondering if the Jeep is driving you or you're driving the Jeep. A "dropped" steering arm will lessen this angle, but it is not a complete cure. There just isn't a steering arm with enough drop to compensate for 5 or more inches of lift. If there were, it would place a huge amount of leverage on the steering box and its mounts, sooner or later, resulting in breakage. There is one more steering related snag. Since you can't lower the draglink enough to be parallel with the tie rod (to eliminate bump steer), the draglink has a steady incline from the axle to the steering box. With that in mind, and the newly relocated springs above the steering linkage, you can see that in a sharp right turn the draglink is going to be pushed into the passenger side leaf spring. You can get around this by bending the draglink, but somewhere in the back of your head you know that there is something inherently wrong with bending steering linkage. Still want to go through with a spring-over? Contact Rubicon Express (www.rubiconexpress.com), they have a spring-over "kit" for YJ's, as well as a how-to video that should be helpful to both CJ and YJ owners. For the majority of Jeep owners, it's probably best to use an off the shelf aftermarket lift. However, if you're concerned about ride quality, contact National Spring (619-441-1901), or any other reputable custom spring manufacturer for a custom set tailored to your needs. In the long run, custom springs will likely be the best compromise between off road articulation and on road driveability, as well as being much easier to live with and less hassle to install.