Suspension Lift vs. SOA

[SeaRubi]

Maybe not full width Dana 60's but 39.5x15x16.5 tires and sits on the road just fine at more than legal speed. Ok, tire noise is an issue with the big rubber, worse than the Hemi - 15mpg. Those little 37 MTR's are almost silent when they are on.

If the geometry is right, things work just fine. But if it's not dialed in it sucks BIG TIME. I have had other Jeep club guys ride in mine, who own Jeeps with 33's and 35's comment how much better mine handles than their Jeep. So if you are prepared to spend time sorting the issues most things can be solved.

Not sure about 1/4, 1/2 Full - elliptical suspension however as that is just crazy stuff . I have seen a YJ near on it's side with the wheels still in contact (just not right)

I don't refute that it can't be built, I just think it's a much more expensive and time consuming route for the average joe looking to do some back country exploration, tackle the occasional obstacle on remote roads, and drive the vehicle to and from those roads over the highway. I think it's much wiser to save all that money for fuel and travel expenses than to put so much effort into the rig.

fwiw.

 

[OS-Aussie]

Many people are more than happy with stock and that is fine. However over time the locations that are targeted can become more demanding and your build and mods change to match these locations, otherwise everyone on this portal would have stock vehicles.

My Jeep is the result of 5 years of work, and built for more demanding locations where it tows an AT trailer or bob tails. But alas it is not the only vehicle we own and we do mix and match for locations.

Just like a Jeep club every Jeep and every owner is different. They all need to pilot their own directions within their limitations (skill and $). I have driven 6x6 rig trucks on super singles that handle better than some peoples Jeeps. But then again I drove Toyota diesels for years and think you can't kill then with a stick.

But enough of this rubbish.......

I still think the Jeep in question is after something simple as I posted earlier.

 

[AZCPP]

OK, You obviously are relatively new to offroading. With that in mind, Scott Brady's suggestion would be your best option. Or a Rubicon Express YJ system would be a good choice also. You would be a lot happier with the setup Scott suggested as it will give you a more reliable and drivable Jeep to get started in this recreation. Scott knows what he is talking about and I have owned and offroaded 12 Jeeps plus my grandfathers CJ over the past 28 years. I have made good choices and some bad ones. One thing about doing a SOA with the stock spring's is that those stock spring's are already quite worn (over ten years), and they are designed to be used in a spring under application not spring over. There is a difference!! You can call OME or Rubicon Express to confirm. Spring wrap in the rear is bad, spring wrap in the front is not safe! A Jeep that is safe and a good driver is a lot more fun than a Jeep that is road wild and unsafe! Trust me I've been there! You will also enjoy the sport a lot more if you build it mild and improve you driving skills verses overbuild it and just point and shoot. My last TJ, I wheeled it for four years with a Rubicon Express 4.5" short arm system. Then I went way Over the top with D60's, full custom suspension with Fox AirShox, and 37" BFG's. It was fun....for a while then, I sold it a year later.

Hopefully this helps.

 

[86cj]

If you are after an improvement in ride quality a SOA with it's flater spring will provide that, even more can be had with a shackle reversal. You just have to be commited to sorting all the bugs out of a complete suspension,and the fact that parts aren't readily available. At this point you have Jeep that is lifted alot and has soft springs, (great offroad but not on the freeway). Stiffer springs help some SOA issues but isn't that what is wrong with a SUA......

I have a SUA CJ with 3" BDS YJ springs, with a 1" BL and some trimming 35"s fit. I think your reliability for camping points to a SUA.You have been driving a leaf sprung SWB Jeep, so if the ride does not bother you now, a high quality (EMU 2.5", 3" BDS or even a 4.5" RE) lift can ride good for SUA leaf springs...

During my research I found the shackle reverse on a Jeep that sees a lot of road miles puts a lot of wear on the front of the transfer case with the front shaft pushing on it every bump in the road. So not only do you need a long travel shaft of critical dimensions it has to stay in perfect working order (clean and greased) all the time to minimize the stress. You also have issues with the tire pushing back into the bottom of the front fender/tub giving less clearance for bigger tires, unless you move front axle forward which can effect steering geometry. I have a V-8 and did not want the hassle of the spring wrap issues front and rear. While the traction bars work they have a rough life and tend to break when when you really need them, allowing more $$ breakage..

 

[AndrewP]

I ran SUA with lift springs for years in my FJ40 (not really a Jeep, I know). It worked well and had few issues. Last winter I did a spring over, and overall, it's a better rig set up like this, but the $500 mentioned is just the start.

You may physically get the springs over the axles for $500, but you won't get a truck that works well, or performs offroad for that. For instance, I have $500 in the anti-wrap bar alone. You will need to figure in new shocks($350-500), longer drive shaft slip joints($500 minimum), new high steer($500+), and different steering links($300). On top of that, you need to figure the fabrication costs if you can't do it yourself. Done right, assuming you pay someone to do the work, I would estimate $3500 or so. The Jeep world seems to cost a bit less, but you get the idea.

If you are new at the offroad game, stay with the SUA leaf springs. Once you know what you like and where you want to go, then consider the spring over, but only with a thorough understanding of what's involved. If you really want to go 4 wheeling in the big rocks, the SOA is a great set up, but for anything else, I think you will be happier with just some lift springs.

 

[madizell]

Wow. There are about three and a half opinions here for every post. Some are experience based, and some are borrowed.

First, if someone offers to do a SOA modification for only $500 that person is either a very close friend who owes you big time, someone who hasn't a clue how to do it and is willing to give it a try, or someone who knows better and just wants to low-ball you into a deal you can't get out of once you start.

SOA looks easy. It is not. It is a highly technical modification that requires a lot of shop time, likely in the neighborhood of $2,000 in cash to cover parts and labor, and is one of those things that can nearly always be made to work, but does not always work out the first time around.

I didn't find a response to the questions regarding why the lift is wanted. Without that information, it is hard to recommend one approach over another. Otherwise, it is just an opinion fest. Here's mine.

The simplest and most likely method to work the first time and at the same time require the least amount of automotive engineering background is spring under with lift springs. Nearly any amount of lift can be achieved this way, with higher or lower spring rates also possible (firmer or softer ride). You will still need a dropped pitman arm either way, but the steering geometry issues are generally fewer and easier to solve with suspension lift.

On the other hand, for a given amount of lift, SOA provides more articulation because it is simpler to increase suspension travel with SOA. With lift springs, travel has to be limited to stock or near stock lengths to prevent over-travel and binding on lift springs, lift being achieved through greater arch and necessarily longer leaves. Since the pivot points of the leaf springs won't change, longer travel can't be accommodated. So, if you are just looking for a bit of lift to clear tires and don't mind limited articulation use lift springs. If you are building toward greater travel and articulation, SOA is the easier way to get it.

Both methods have their own good and bad points, and both have issues. Spring wrap is probably the most difficult SOA issue to control, but depending on how and where you drive, and who you buy springs from, it may be a non-issue. My SOA CJ-7 has 300hp and 325 ft/lb torque, and while there is axle wrap (not avoidable without triangulated arms) it hurts nothing because the springs handle the job. Lots of trucks are SOA from the factory and don't have traction bars, yet work just fine. Traction bars are a drag race item not strictly compatible with off-road driving unless you have very limited articulation. NONE of the bar systems out there actually work with a vehicle that ramps over 1,000 RTI. They will bind, and the brackets will break or the bars will bend. An anti-wrap or overload leaf on the bottom of the pack does a better job than a bar. Take a look at most factory systems on SOA leaf packs (such as Toyota or Nissan).

Assuming that you just want to clear larger tires and are not looking to build the next US champion rock machine, use lift springs and good shocks. Anything 4" and up will require a dropped pitman to negate increased steering arm angles associated with lift. I use one with a 2 inch spring lift even though it is not strictly needed because in my case, it brought the arms back to parallel. You can buy complete, engineered spring kits for your YJ. You can't find a complete, SOA kit as far as I know because there are too many variables involved, and all SOA modifications require cutting and rewelding on the axles, which is something that a kit manufacturer could not control and would not want to be responsible for. As a rule, SOA costs more than spring lift, requires more technical knowhow, and won't last as long once completed.

And, to re-emphasize a point made by Scott earlier, SOA will net you a minimum of around 4 and a half to 5 inches of lift, all other things being equal, if all you do is relocate the perches to the top of the axle. That is a lot of lift which can just as easily be achieved with springs. What would be the point of that? My CJ has 8 inches of aggregate suspension lift and one inch of body lift. The spring maker offered to build me a set of 8 inch springs, but I would have been limited to stock or near stock travel because I would have had to drop the bump stops in an amount equal to the increase in lift. I wanted more. I now have a conservative 12 inches of travel front and 10 rear which I could not have had with 8 inch lift springs because the packs would bind first, which could be really bad for the springs. But most folks aren't trying to build what I was looking for. If you are, springs along won't do it. If you are not, stay with lift springs.

 

[mizedog]

Ok. Great info but let's boil it down.

If you're planning on much road time, stay SUA with Rubicon Express's Extreme 4.5" kit. It will flex much more than the average SU set up and still ride pretty well. It bucks the SUA's normal trend of rough ride and gives you the choice of 33's or 35's.

If you're looking for a rock crawler that isn't a daily driver, SOA will flex much more. But, don't reuse you're old springs, and don't count on $500.00.
Go with Rubicon Express's 1.5" YJ reverse eye springs. They were designed specifically to limit axle wrap in a SOA use. Also, get new spring perches that are longer (helps more with axle wrap).

My CJ-7, and my buddy's YJ use these springs in a SOA set up. Mine gets 1500 on a 20* ramp! It doesn't have axle wrap (thanks RE). But, it's not a road king. It's actually quite scary in corners and going down dirt roads. I can't comfortably keep up with YJs and TJs on dirt roads without floating all around. I don't have any sway bars (just one more of those hidden details everyone mentioned when doing a SOA). But, my Jeep flexes REALLY well in the rocks.

You simply need to consider where you really are and want to go. If you expect to go 75 mph down the highway, you're probably going to have white knuckles (I do). Also, don't get Detroit lockers if you go SOA and expect to hit the highway. Get ARBs or Oxes. My flexy Jeep actually changes lanes on me because of the lockers.

If I were to do my CJ all over again, I would go with the RE 4.5 SUA kit. It's complete and will cruise down the road and tackle just about any sane obstacle you want.

P.S.: It is nice to see people amazed at how easily the old junk pile cruises over crossed up sections.

Oh. I just got a JK cause I want to hit the highway with the kids inside instead of flat towing my old CJ.

 

[Oman4x4]

The real question is how much do you want to spend.

I am running coilovers all round and love the ride, way more than stock, or a couple of other after market kits I have used.

Do you have a build-up thread somewhere? Looks like an amazing vehicle.

 

[Oman4x4]

For an mild expedition type vehicle - I'd probably go with a 3" lift and some Bushwacker cut-out fender flares and tuck some 33" tires in there.

For a more extreme rock crawler - then SOA starts to make sense. the ~5" of lift you get allows for some pretty big tires.

Also keep in mind you most likely have the Dana 35 rear axle - so unless you plan on swapping that out - you really should consider 33" your upper limit.

 

[OS-Aussie]

Do you have a build-up thread somewhere? Looks like an amazing vehicle.

You know you are not the first person to ask, even my Jeep club hits me with that one.

I will have to stop being so slack and do one for both my Rubicon and Cherokee.

Quick 5 on the Rubicon

I moved to Texas from California with my Job and looked at a lot of the wheeling in Arkansas and Oklahoma and thought that we would need to go to bigger tires. This then had a cascade effect on the rest of the Jeep. 39.5’s, 35 spline dana 60’s front drive flanges rather than hubs, 4 speed Atlas, 14 coilovers with front air bump stops, hydro assist steering, 5.7 Hemi from a 2006 Grand Cherokee including the 5 speed auto. Front and rear 6” tube fenders, PS rockers, trans and motor oil coolers, GenRight gas tank, airraid cold air intake etc etc etc………

Full doors, half doors, hard top, soft top, 5 x 15 wheels with 39.5 x 16.5 pit bulls, 5 x 17 wheels with 39.5 x 13.5 iRoks, XTC light bar, rock lights, PS trail stinger, PS full cage, Corbeau seats with 4 point harness, Nth Degree Tummy tucker, Nth Degree long arm kit, Replaced Nth rear LA with GenRight 4 link kit to address mis-alignment.

5.13 Gears with ARB air lockers front and rear, Atlas with 5:1 and 10:1 low range. All LED park lights and rear, Warn 9000 XD winch.

(Green Mamba, Clayton OK)

Curently I have a set of 37x17 MTR's on the Jeep testing the difference in handling. However it does not feel much different from the 39.5 iRok's to be honest.

Yes this Jeep does tow my early model Adventure Trailer.

(North Padre Is, TX)

 

[madizell]

If you expect to go 75 mph down the highway, you're probably going to have white knuckles (I do).

I would attribute this to your lack of anti-sway equipment. Mine reacted similarly until I installed Currie Anti-Rock's both front and rear. They do tend to limit ultimate articulation, but I was not building to ramp or crawl rocks. I wanted high speed stability off road.

Not unstable on dirt roads now. We did a stretch of dirt road in Australia at 85 mph, and it was a one-handed affair (I still used both hands, and we would have been going much faster, but I didn't have time to raise tire pressures from the 13 pounds they had coming off the prior event). Routinely did 65 off road where there were no roads or trails, day and night. Still does 75 or more on the highway and drives just about like any short wheelbase truck with 37 inch tires.

So, SOA does not need to be unstable, but you do need to build for stability.