SOA advice?

SOA advice?
T

tdkask

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Location
Virginia Beach, VA
Vehicle(s)
1979 CJ-5
I am the proud new owner of my first Jeep, a 1979 CJ5 . It is surely a heap of rust and will cost me a fortune to make how I want it, but I love it for it's fun and its promise of hours of tinkering. I'm not new to wrenches, but am new to 4WDs, and wanted to come to the forums for advice and the wisdom of those who have done things right or wrong before me. :)

Aside from rust in the tub and a couple body mounts, I have few complaints. It has a strong AMC 304 and has already recieved some lift and has 33x12.5 on it. I don't know how to tell what the lift amount was, but there is plenty of room with the 33s, so assume it to be 4" or so.

That lift, however, is where my problems lie. I am pretty sure that everything was done in the front for steering to account for the lift as there is nothing hitting and it steers okay (except needs tie-rod ends and bushings) and the front seems to handle okay, so I probably won't mess with the front too much, as it drives fine.

The rear, though, needs some changes. The springs are WAY too stiff, and make even the tiniest speed bump at even 2-3 mph feel like my spine has been crushed, as if maybe the axle were welded to the frame. I imagine this was older lift springs with a wider arch and very stiff to keep the frame up high, but allows for no bumps. It is way to rigid and has no flex. This just doesn't seem like what an all-terrain vehicle should be about. Small dips or potholes shouldn't hurt that bad... :D SOOOO... it has to change.

So here are my questions (finally). First, how do I figure out what the lift amount in my CJ is? I can measure the distance between spring perch and frame, but need a stock comparison. Then if it is 4" or so (as suspected) then I should get about the same height out of a SOA setup with stock YJ springs, right? I have a friend with a Wrangler and assume the springs will be about the same (almost flat) and could compare from there with the bow of those springs.

Again, remember I am just talking about swapping the rear to SOA and stock springs, while leaving front with present "lift springs" and all. If I keep the same (or approximate) overall lift by trading the rear lift springs for SOA and stock springs, will everything else pretty much be the same? Will the added flex allow for problems in drivetrain alignment that was not apparent in such a rigid setup as now? I will try to get pics tomorrow with the wheel off and the axle on jackstand to show the difference in weight-on-wheels and no-weight-on-wheel, but not much variance.

Thanks for any suggestions. I appreciate any help or advice you can offer.

tdkask
 
Some off roaders do a single spring over and spring under on the other but it is usually the other way around. they spring over the front and spring under the rear and that is due to the wheel hop issues that show when doing a spring over on the back. Spring over on the front allows for more flex and spring under on the back controls wheel hop and aids to side stability. I think you would be much better off just going with a quality lift kit that has better springs. I have a 4 inch lift on my CJ5 and it rides just fine. I use Black Diamond springs. Dont forget if you go the way you are suggesting the springs rates wont match and that means the valving wont be right on the shocks. You will get some funky handling on the street that could be dangerous.

Oh and virginia has a 28" max bumper height lift law for vehicles that have a gross weight of less than 4500 pounds. The spring over most likely will put you over that amount.
 
Kane said:
Some off roaders do a single spring over and spring under on the other but it is usually the other way around. they spring over the front and spring under the rear and that is due to the wheel hop issues that show when doing a spring over on the back. Spring over on the front allows for more flex and spring under on the back controls wheel hop and aids to side stability. I think you would be much better off just going with a quality lift kit that has better springs. I have a 4 inch lift on my CJ5 and it rides just fine. I use Black Diamond springs.
Click to expand...

Thanks for responding. I read about the wheel hop. Would this be an issue if I don't do a lot of off-roading? I will occasionally play a little, I guess, but hadn't expected anything very extreme, and usually will just go through a mud puddle in the rain or something... definitely not rock-climbing. :) As I understand it, about the only way to eliminate the hop would be a ladder bar, and that's more than I wanted to do. Is it a serious andsignificant (in my needs) concern?

Kane said:
Dont forget if you go the way you are suggesting the springs rates wont match and that means the valving wont be right on the shocks. You will get some funky handling on the street that could be dangerous.
Click to expand...
As for shocks, I would have my local 4WD shop lead me the right direction there, I guess. How does one figure all of that, anyway?

Kane said:
Oh and virginia has a 28" max bumper height lift law for vehicles that have a gross weight of less than 4500 pounds. The spring over most likely will put you over that amount.
Click to expand...

I wouldn't be changing ride height significantly. I would leave the axle about the same distance from frame relatively, and would be moving a flatter spring to the top of it. Not sure if that mental picture makes sense, but basically if the wheels were on the ground and the frame were on jackstands, and you imagine only moving the spring to the top of the axle and straighter (flatter, less arch/lift)

Again, thanks, and please keep the thoughts coming. Especially about the concerns mentioned... Is it a huge issue under normal daily driver applications (with light offroading) and how can it be eliminated? Will long perches lessen the spring wrap and resulting wheel hop?

Thanks.
tdkask
 
tdkask said:
As I understand it, about the only way to eliminate the hop would be a ladder bar, and that's more than I wanted to do. Is it a serious andsignificant (in my needs) concern? Will long perches lessen the spring wrap and resulting wheel hop?

Thanks.
tdkask
Click to expand...

longer perches help very little, with the softer yj springs you will realy need some sort of ladder (traction, bam) bar. or you will get spring wrap.

A spring over, even with yj springs usually gets you about 5" of lift.

I'm with kane, a good quality sua kit will ride just fine and you won't have all the problems of a soa.
 
SOA has great advantages for offroaders.
For a street rig I see no real advantage.
SOA done right is no cheaper than a "Lift Kit", maybe more.
CJ5 's have a lot of rear drive shaft issues if you lift it more than 4"-5".
Anyway that's my opinion.;)
 
I expected to be able to do SOA for about $50 since all I need is junk yard axles and some perches I weld in place, but if it's that unrecommended...

Assuming I am going to replace the springs with a SuperLift SoftRides, but want to go cheap, I can buy just the rear springs (already have NIB prothane bushings) from summit for $70-$100 each, depending on lift. How do I find out the amount of lift I have right now without swapping in stock springs (that I don't have) for comparison? What resources are there for knowing how far a stock spring sets the axle from the frame? Does anyone have a stock springed CJ?

Thanks for all the help, BTW.
 
tdkask said:
I expected to be able to do SOA for about $50 since all I need is junk yard axles and some perches I weld in place, but if it's that unrecommended...

Assuming I am going to replace the springs with a SuperLift SoftRides, but want to go cheap, I can buy just the rear springs (already have NIB prothane bushings) from summit for $70-$100 each, depending on lift. How do I find out the amount of lift I have right now without swapping in stock springs (that I don't have) for comparison? What resources are there for knowing how far a stock spring sets the axle from the frame? Does anyone have a stock springed CJ?

Thanks for all the help, BTW.
Click to expand...


You'll need longer brake lines.
You'll need to address your caster angle.
Lengthen both drive shafts, may need CV joints.
To do it right, IE no bump steer.
You'll need a high steer setup.
That's a lot for $50. Bucks.
Granted it can be done cheaper, but you risking not only you & your passengers lives, but everybody else on the road.;)
 
Sorry, Longhorn, but I think you missed a detail that effects my situation. The CJ is already lifted (probably 4"? but I am not sure... has 33's) but has a very rigid ride, especially the rear. All I want to do is keep the same height as present, but with a more forgiving ride. That means swapping over the springs to something with more flex. I was asking if that is better done with a stock spring w/SOA or with a different configuration. The responses here are convincing me to spend the bucks on decent lift springs, if only to prevent axle wrap.

My first intuition is to assume that if a rigid-springed 4" lift has no concerns with present brakelines and driveshaft then likely the same amount of lift with more flexible springs would be okay. But my concern after consideration is that allowing the wheels to drop further down (greater flex) would cause me to overextend the geometry. How do I test this? Simply jack up the frame with shackle unbolted and see how far it can go before there are concerns? Will moving the axle 1" forward help alleviate driveshaft problems? Thanks.
 
tdkask said:
Sorry, Longhorn, but I think you missed a detail that effects my situation. The CJ is already lifted (probably 4"? but I am not sure... has 33's) but has a very rigid ride, especially the rear. All I want to do is keep the same height as present, but with a more forgiving ride. That means swapping over the springs to something with more flex. I was asking if that is better done with a stock spring w/SOA or with a different configuration. The responses here are convincing me to spend the bucks on decent lift springs, if only to prevent axle wrap.

My first intuition is to assume that if a rigid-springed 4" lift has no concerns with present brakelines and driveshaft then likely the same amount of lift with more flexible springs would be okay. But my concern after consideration is that allowing the wheels to drop further down (greater flex) would cause me to overextend the geometry. How do I test this? Simply jack up the frame with shackle unbolted and see how far it can go before there are concerns? Will moving the axle 1" forward help alleviate driveshaft problems? Thanks.
Click to expand...

SOA will give you more than 3" of lift with stock Wrangler springs,
more like 6" or 10" if you include 4" springs.
The flatter the springs the better the ride.
If you want 6"+ lift with good ride consider Rubicon express reverse eye wrangler springs with a SOA setup & shackle reversal.
As far as flex damage, to prevent over flexing you use limiting straps & for compression you use bumpstops.
As far as testing I use a pink granite bolder in my yard & a fork lift.
 
LongHorn said:
SOA will give you more than 3" of lift with stock Wrangler springs, more like 6" or 10" if you include 4" springs.
The flatter the springs the better the ride.
Click to expand...
I definitely follow you there, but want about the same ride as now, only better ride, which is why I wanted to swap the (rear only) lift springs for SOA/stock flat springs, and hoped to keep same height.

LongHorn said:
As far as flex damage, to prevent over flexing you use limiting straps & for compression you use bumpstops.
Click to expand...
That makes sense. I guess the best way to prevent over-flexing is to physically block it. :) I didn't expect that much flex anyway.

LongHorn said:
As far as testing I use a pink granite bolder in my yard & a fork lift.
Click to expand...
Well there you go... I just need a boulder and a forklift... lol.

Actually, I just finished a smaller scale similar test to satisfy my curiosity. I can put one rear wheel on a little 10" ramp from parts store and the other barely touches the ground. I have NO FLEX... lol.

I lifted the rear just now, with the left wheel on the ramp and the right side frame (where front of spring bolts to frame) on a jackstand such that the wheel was in the air. I measured out the distance between the frame and axle on either side to see how much my axle drop was when weight was off the wheels... 1 inch. Yep, when my left wheel is on a "rock" and my front wheels are level, my right wheel only has minimal distance (not accounting for frame flex) before I'm spinning a tire. Id's say less than 12 inches of height difference would leave me with a spinning tire.

I assume this should not be the case... one foot of articulation? If you were to pick up one wheel with a forklift with decent lift springs how high would you expect to get it before the other tire left the ground? Surely this is the cause of my horribly stiff suspension and rough ride, as well as the fact that I can get "stuck" in 2WD in a small ditch at an angle. Would I expect to see this better with something like a set of SuperLift SoftRides 4" springs or something similar?

Thanks.
 
How CJ experience do you have?
Short wheel base, leaf springs, straight axles, stiff shocks & off road tires don't tend to have a good ride without a lot of work.
Even then it's not a Jaguar.;)
 
tdkask said:
I definitely follow you there, but want about the same ride as now, only better ride, which is why I wanted to swap the (rear only) lift springs for SOA/stock flat springs, and hoped to keep same height.


That makes sense. I guess the best way to prevent over-flexing is to physically block it. :) I didn't expect that much flex anyway.

Well there you go... I just need a boulder and a forklift... lol.

Actually, I just finished a smaller scale similar test to satisfy my curiosity. I can put one rear wheel on a little 10" ramp from parts store and the other barely touches the ground. I have NO FLEX... lol.

I lifted the rear just now, with the left wheel on the ramp and the right side frame (where front of spring bolts to frame) on a jackstand such that the wheel was in the air. I measured out the distance between the frame and axle on either side to see how much my axle drop was when weight was off the wheels... 1 inch. Yep, when my left wheel is on a "rock" and my front wheels are level, my right wheel only has minimal distance (not accounting for frame flex) before I'm spinning a tire. Id's say less than 12 inches of height difference would leave me with a spinning tire.

I assume this should not be the case... one foot of articulation? If you were to pick up one wheel with a forklift with decent lift springs how high would you expect to get it before the other tire left the ground? Surely this is the cause of my horribly stiff suspension and rough ride, as well as the fact that I can get "stuck" in 2WD in a small ditch at an angle. Would I expect to see this better with something like a set of SuperLift SoftRides 4" springs or something similar?

Thanks.
Click to expand...


The isssue I have with most "soft ride" springs is they achieve a soft ride by reducing load carrying ability.
So if you carry two people & a cooler in the back you have sag & sway problems.
 
LongHorn said:
The isssue I have with most "soft ride" springs is they achieve a soft ride by reducing load carrying ability.
So if you carry two people & a cooler in the back you have sag & sway problems.
Click to expand...

Once again we enter the realm of opinion.
I guess everything has to be a trade off. When I bought the Skyjacker springs, these many years ago, I read that they were made from 5160 spring steel; most leaf springs are made from 1095 spring steel. 5160 is primarily used in coil springs, they flex smoother than leaf springs and one of the reasons is because of the 5160 alloy. Skyjacker also “pre flexes” the spring before it is shipped to relax some of the stiffness with out loosing load capacity or arch. I did fill the back up with rocks and found that it was a bit squirrelly at 65 or 70 but I don’t recall it sagging a lot. The ride is better than it was stock. I do not have a back seat so my opinion may be Limited as to passenger carrying ability.
:cool:
 
IOPort51 said:
Once again we enter the realm of opinion.
I guess everything has to be a trade off. When I bought the Skyjacker springs, these many years ago, I read that they were made from 5160 spring steel; most leaf springs are made from 1095 spring steel. 5160 is primarily used in coil springs, they flex smoother than leaf springs and one of the reasons is because of the 5160 alloy. Skyjacker also “pre flexes” the spring before it is shipped to relax some of the stiffness with out loosing load capacity or arch. I did fill the back up with rocks and found that it was a bit squirrelly at 65 or 70 but I don’t recall it sagging a lot. The ride is better than it was stock. I do not have a back seat so my opinion may be Limited as to passenger carrying ability.
:cool:
Click to expand...

No doubt every rig is different, I carry one sometimes two back seats & that 38" on the tire carrier.:eek:
So loaded can be a relative thing.;)
 
LongHorn said:
No doubt every rig is different, I carry one sometimes two back seats & that 38" on the tire carrier.:eek:
So loaded can be a relative thing.;)
Click to expand...

Like you said yourself your not gonna be rock crawling and when you get to know longhorn, he owns a beautiful chunk of land in the great old state of texas, where he enjoys crawling through creeks, so we all know what he does, stays warm and plays hard. As far as lifts go, I personally would go with a 4 inch BDS because like Longhorn said you sacrifice Load capacity, and that would bother me because i would want to be able to carry as much as possible without problems, Like here in Montana, I have decided to build my rig for mud bogs instead of rock crawling, because there is only 1 or 2 trails for crawling and they have a lot of mud bogs around here.
 
There are a lot of great opinions on spring rates here but something to consider is what shocks you are using as well. some seriously stiff shocks even with the best spring rates will feel like your spine is beeing shaken not stirred......trick is to find a good combo of both ;)
 
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