SOA: Where's the benefit?

Been wandering around various late-CJ sites (I know, that's my first problem, right?) trying to find some trivial pieces of swap info (Tim, that 151 bell does go SBC to Ford.) and I've noticed along the way that SOA lifts seem to be VERY popular with the '76-'86 crowd. Two things in particular stand out to me.

First, SOA seems like THE solution, not A solution, among these sites. I'm having a hard time figuring out why. People try to site "tire clearance" and "flex" as their number one and two reasons. Tire clearance I can understand. Flex? I don't get it. How would moving the axle to the underside of stock spring give the stock spring any more flex? It seems to me going SUA with a soft spring that has more arch would potentially provide more flex than SOA on stock springs. What's the skinny?

The second thing I've noticed, and this is why I'm posting here not there, is that woe be unto ye that may question the wisdom of the masses that are advocating this type of lift. A lot of guys get on there and say "Why is my steering wandering?" or "Why do I have these driveline vibrations?" and people get really defensive when someone suggests maybe SOA wasn't the route to go. Does SOA by itself have a tendency to reduce castor and mess up driveline angles, or is that just shadetree engineering screwing up something that is really simple?

 

Indeed.

 

Exactly what Sparky said. As far as I can tell, if you have some pretty good fab skillz and know what you are doing, SOA can be a pretty good cheap way to get more tire clearance. We do SOA on alot of rigs that are swapping in 1ton axles, but those are not driven on the road, the wheelbase is usually stretched, and the axles are wider so lifting that much doesn't hurt the stability. There are just wayyyyy to many people out there who do the SOA only as a reason to stuff bigger tires under their Jeep, and they don't do it right and they then try to drive it on the road and run into all kinds of problems. I have also found that most folks doing the SOA have absolutely no idea how anything under their Jeep works. Like Sparky said, it can be done right, and then you can get bigger tires under there, but on a Jeep with stock axles I just wouldn't want that much lift. Heck, alot of these guys are doing the SOA (adding about 5-1/2" of lift) and then getting 4" lift springs on top of that trying to clear 44's or tires close to that, and trying to run stock axles.

Only benifit I see to it is tire clearance, and I would much rather comp cut the fenders than to do the SOA. It might give a little more flex, but I would say alot of that is because the springs are worn out from the axle wrap.

 

I had a 63' with a SOA, 36" rubber and it scared the heck out of me. Not to mention the awful front end hop at around 35 mph. The first thing I did when I got it home was buy a good 2" lift and put it back the way it was supposed to be.

I had a friend that owned a 4x4 shop and did the swap on his CJ. He eventually went back to stock because of all the problems he had. Axle wrap and springs breaking among the 2 biggest problems.

 

With the spring over axle you have more clearance under the axle.

If you do this you have to understand castor and the right tools to reset it correctly.

Axle wrap is an ugly experence. I wouldnt drive one without a real torsion bar.

IMO The springs we use wernt realy designed for this.

I have seen a few rigs where they even add'd blocks under the front axle.

On our rigs of choice 2.5 inch spring lift SUA makes the most common scense... IMO.

On a trailer queen do what you want but for DD we have to use some common scense. Sooner or later it will be inforced upon us... IMO.

 

I don't think you get more flex with more arch. It's more desirable to have a flatter spring. Kinda like what Rick Pewe did on his flatty many years ago - flat yj springs and SOA.

You do gain lift, ground clearance, and flex with SOA but you also get axle wrap and other problems - for most people it's not worth it. I wouldn't even consider it on an Early CJ5 that is driven on the road.

I've seen rigs that couldn't make it up a hill climb after going SOA that they could make before.

 

My understanding of leaf springs is that the spring has the most leverage on the axle when that axle is mounted near an imaginary line drawn between the spring mount eyelets. Move the axle away from that line, as with an SOA, and the spring looses it’s advantage over the axle or the axle gains leverage on the spring which results in more flex.
Course, more flex is like more alcohol. Moderation is required.
More flex with a leaf spring suspension will mean more “axle wrap”, as others have pointed out, and the only way to reduce the amount of axle wrap is with Band-Aids like some sort of traction bar(s).
At one time SOA was the best way to get lift and flex, but now since leaf spring manufactures have been in the market for a while that isn’t necessarily as true. Many lift kits that stay SUA can have very impressive flex.

The handling problems sound like shade tree engineering though. I’ve seen several properly set up SOA rigs that handle fine, at least as well as a mildly lifted SUA ones.

 

That was my initial reaction as well; like they see the price tag of a spring kit and think they're going to be "saving" x number of dollars, when in fact they're going to be spending all that money on fab work, anyway. I also think, and this is not meant as a bashing, it's fair to say that the median age on some of the sites is significantly lower than say, on this site, for example; I've noticed that some of the guys advocating SOA are possibly too young to have ever wrenched bolt-on mods into place, much less engineer something as custom as what I think would be necessary to really do SOA the right way. I was just curious. Thanks for all your inputs.

 

Dummy/Hazel just had an article in JP about this. He switched from SOA stock YJ springs to ,I believe, RE YJ 4" SUA. His reaction was that it was a huge amount better.

Aftermarket spring manufacturers have some really good flexy springs that can be mounted SUA.

Custom spring packs seem to be the way to go SOA. Then I think they are only making them stiffer and you loose the flex.

How about shackle reversal. Is it a no brainer to go ahead and do it? Or, are there some cons?

 

I gotta agree with you there, and you can tell based on the fact that the guys on other sites want to argue with you if you say anything against what they run. Here, most everything is constructive critisism (or however you spell it). I wouldn't really call anyone here old, but I'd say more mature and more experienced with this stuff. I'm still kinda a youngster, and there are guys here that are alot younger than me, but still have had the experience to know what works and what doesn't.

Basically, I see it as this....

SUA Lift = Bolt on.
SOA Lift = Alot of fab work.

If you don't completely understand how the suspension and steering on the vehicle works, then you have no business doing any fab work on a vehicle that will be driven on the road. In that case, you should take it to somebody that does understand how everything works and pay them to do it, which will cost you more than the do-it-yourself bolt on lift kit.

Also, as far as trail riding and Jeeps go, the whole "the bigger the better" thing just doesn't make much sense. Alot of the offroad rigs I work on are running 44's SOA, but they also have the wider axles and a stretched wheelbase to keep it stable, and if it was easy to do SUA with them they would be. Even at that though most run stock CJ rear springs on the front and four link setup on the rear to match the ride height and keep it as low as possible, instead of just trying to build the thing as tall as we can like I see most folks doing with the SOA. Not to mention that these things aren't driven on the road.

I would imagine it's pretty safe to say that alot of those guys running the SOA are slingin ujoints out pretty regularly.

Of course don't get me wrong, I'm not completely knockin the SOA, cause if done correctly it can work great.

 

As long as you have a long travel driveshaft, I say go ahead. Without the long travel driveshaft, you'll be replacing t-cases and transmission housings if you get in some good rock trails, or at least that is what I have seen and also the reason that I know several folks going back to the shackles in the front.

 

From what I have seen in this hobby in the past 6 or so years is SUA is getting to be the way to go. Not because of this or that but because the spring manufacturers have learned how to get hight without making the ride rediculusly stiff and give good flex at the same time. Basicly leaf spring technology has not come to a stop by any means, it is still moveing forward.

 

My SOA cj-5 has better driveability now than it ever dreamed of having stock. BUT, I put 6 degrees caster in it which is about 6 more than stock. I properly installed true high steer and my tie rod and drag link are nearly parallel. I run longer, wider springs. I lengthened and widened the wheelbase. I have superb driveshaft clearance. This Jeep now has great articulation. Everything seems better now than it was when it had either the 4" or 2.5" SUA set-up. But I did not buy any kits of any sort to do this. Every piece was engineered and built by me for my particular Jeep. I am a strong disbeliever in kits because they never seem to be exactly right, even simple spring lift kits. If you want it to be right, you have to do it yourself, period. And as has been stated, SOA lifts must be installed correctly to be right.
You do not have to be young to be a SOA supporter.
I am 42 years old.
I have been jeeping for 26+ years.
Yes everyone, I am a Jeepaholic.

 

I want to go back down to the stock height on my '60, mainly 'cause the old 'Tilto-O-Meter' in my head says I'm pushing it by leaning all that higher center-of-gravity too far. I'm running off towards 56 this next spring, and the decrepid old bod just don't mend as fast as it used to.
Plus I don't like tearing up the equipment that much.
I still like running around the desert north of Phoenix, just don't do the more aggresive stuff anymore.

 

Soo, as I read this, I have to ask....

If I were to go with a Lift KIT...what is too high for a SWB CJ5 like mine. I was starting to think about a 4 in, but as I start considering that my family out playing most of the time, and the TILT O METER effect is not welcomed by my son...I am leaning toward the 2.5 in and I plan on staying SUA. This is my DD around town with some time in the desert and mountians with some minor Jeep trails. Family time in the hills...not extreem off roading with 40 in mudders. I won't run bigger than 32s, currently running 31.

I am no engineer. I work in a cheese/whey plant, and I fight fire....I don't do engineering. If I was looking for a respectable, workable lift kit, what would the masses here recommend? I ask because I respect the amount of experiance this site seems to carry and offer freely.

Besides, you know how you get good experiance don't you......

Survive bad experiance.

 

Lot of guys around here run 2.5" SUA in their ECJ5.