I was watching Spike channel the other night and I saw them do a Spring over Axle lift on a jeep. Is this applicable to an Xterra as well? I see all these lifted X's, but the axle is still under the springs.

Educate me, why is this? Is it not as simple/cheap as the show made it out to be? Is it now the best way, i.e. there's a reason the axle is over the leaves?

Without doing a SAS, there's not currently a way to get the front lifted by the same amount. Doing a spring over switch will net close to 6" of lift. (the thickness of the axle tube and spring perch plus the thickness of the spring pack).

Not to mention you would have some serious axle wrap that would need to be controlled.

Wouldn't be any worse than a 4x4 Frontier. They're SOA.

Why not get a set of Frontier 4x4 leaf packs, and do a SOA conversion using those? That'd at least net you some clearance under the rear axle. Won't get you any height w/o an AAL, I don't think, but it would give you a couple more inches of clearance under the tubes.

I was thinking about a coil setup.. my bad

Actually, Carlton and I were talking about this a while ago, and we stopped by a dealer to look at the frontiers. Their spring hangers are different than the xterra in the front - they don't hang down as low, or the frame arches up at that point (I can't remember exactly what it was) but it gives them much less lift in a SO setup.

Carlton, huh? A coil/link set up has zero axle wrap. Wrap is a function of leaf springs...the axle rotates up and twists the pack.

Frontier leaves would be pretty soft on an Xterra, as the rear of the X is heavier. That, and Frontier leaf packs are considerably shorter than X leaf packs, so they wouldn't bolt up anyways. The X packs would need additional leaves to keep from going to a negative arch....SOA puts greater forces on the spring than SUA does. Springs that are adequately rated on a SUA applicaiton will be very soft and will eventually lose arch when flipped to SOA unless you do something to increase the spring rate (like add more leaves).

Andy.. I was thinking about the track bars. And the need to add them to control the axle. Either way.. I am going to go back to nursing my cold medicine.

Ok, so obviously there are reasons why not to do this. But how do other vehicles deal with it? Sorry to say the "J" word (jeep) but it doesn't seem to be a problem for them. I guess their solid axle front allows for matching the rear's lift.

Desert_Rat, how does a SOA put greater forces than SUA?

hellfyre, you hit the nail on the head.

A jeep doesn't have an IFS front end except for the Liberty and the new Grand. Therefore whatever way they choose to lifdt the front of their vehicle it will able to match the lift in a SOA conversion. A spring-over is guarenteed to net at least 5" of lift. In order to make this lift worth it you must be able to get 4" in the front and thats just to give it a rake.

The Xterra can only be lifted 3" in the front as of right now unless you do a solid-axle-swap. If you do the SAS then you could do a SOA in the rear and get new leaf packs made with the proper spring rate.

I will be doing a SOA conversion before gone, but will be doing a lot of cutting and rewelding to limit the amount of lift. Removing the front spring perches altogether and replacing with some from a 2.5" Jeep universal kit.

I'll also be shifting the springs inboard about .5" to get them directly under the frame. Since I'll be rewelding the perches (reusing the stock perches) I can pretty much put them anywhere I want. I'll be getting rid of the ABS stuff, as the SAS will null and void any ideas of antilock.

With the body lift that's already on mine, I'll also be lifting the gas tank up the additional amount of the body lift. Thinking of kicking the engine and trans/t-case up an inch or so as well. Good to know decent welders!

Theres a lot more leverage on the springs in a SOA than an SUA, especially when you hit the gas. It wears out springs faster. Guys with YJ's who go spring over typically take all the arch right out of the springs after just a few wheeling trips.

Be a good excuse to go with a custom Orbit Eye spring setup.

I could see eventually 3 linking the rear, but that would be a long, long way down the road.

But when I win the lottery....

Its not that spring over is bad, its just that people try to use their stock "spring-under" leaf springs for the S-O setup and that won't work. The spring rate is too soft and axle wrap becomes a problem.

All half-ton and bigger pickups use the spring over set-up from the factory, but they also use a higher spring rate to counteract the effects of springwrap since their torque is coming from a much larger engine that any of us have.

SOA conversion is just one of those things that you can do it rght the first time or you cna do it half-a$$ed and keep fixing the problems as they develop.

So, explain how the spring rates would have to change, since it's holding the same vehicle.

The problem that folks run into the most with the SOA is that they don't limit the amount of uptravel for the new setup, overflexing the springs. That causes cracks, breakage and failure. That's the single biggest problem I've seen with the SOA setups.

I'd like to hear the change in the spring rates needed, because I'm not buying it. Axle wrap causing the problem with the SOA isn't something I'm buying either.

I'm sure you know, but spring rate is not only about having weight support of the vehicle. Its also about fighting the forces of power and leverage. In a SUA the leverage applied ot the springs is also applied to the axle tube which is wide and pretty static. In a SOA, the only thing the axle is flexing against is the plate on top of the spring pack holding it too the axle tube.

If you add a supercharger to your vehicle and have more power and torque going to the wheels will you get more axle wrap even though the weight over the rear wheels is the same? Of course, so you'll either need some sort of traction bar or you'll need different springs with a higher spring rate. The best way of course would be to get a leaf pack with more leaves that are thinner. You can control more power and still retain great flexability

Over flexing certainly has its place in the blame for failing springs, but if youre leaves are too soft then would you rather limit articulaion or replace weak springs with a better spring pack?