Leaf Springs for SOA Help

[cjhank]

Alright fellas I am about to start an axle upgrade project. I will be narrowing a Dana 44 front from a chev pickup and using a Dana 44 out of a izuzu rodeo for my rear axle this set-ups wms to wms is 64". Now that i have figured this out I need help with the springs. My current set up is a spring under 4" lift set up of some kind that was on it when I purchased and obviously i cant use those leaf springs for my spring over. So my real question is what leaf spring do I use for my swap? Do i go with the stock CJ springs which doesnt seem like the best spring to use for a good suspension set up or do I go with a stock YJ spring? Or should i go completely custom and put longer springs on front and rear for more flex? I am not affraid to do my own fab work. I am planning on doing a reverse shackle on the front anyways so maybe this would be a good opportunity to do longer springs.

 

[gert]

I can tell you what I am using in my build, which is stock YJ springs

 

[Torxhead]

There are a number of custom leaf spring makers around, and they do make a spring specially for the soa. Alcan in Colorado is one of them, search around in your area also.

 

[cjhank]

I dont think I will buy aftermarket its to expensive especially if i can find something used at the junk yard and just clean it up for a 1/16th the price.

The YJ springs may be my best bet I just need to find one to pull measurements off of and check spring rates. Unless someone on hear already knows the spring rates on stock YJ Springs?

Eye to eye are yj springs the same as stock CJ or are they different?

 

[Cornfed]

Alright fellas I am about to start an axle upgrade project. I will be narrowing a Dana 44 front from a chev pickup and using a Dana 44 out of a izuzu rodeo for my rear axle this set-ups wms to wms is 64". Now that i have figured this out I need help with the springs. My current set up is a spring under 4" lift set up of some kind that was on it when I purchased and obviously i cant use those leaf springs for my spring over. So my real question is what leaf spring do I use for my swap? Do i go with the stock CJ springs which doesnt seem like the best spring to use for a good suspension set up or do I go with a stock YJ spring? Or should i go completely custom and put longer springs on front and rear for more flex? I am not affraid to do my own fab work. I am planning on doing a reverse shackle on the front anyways so maybe this would be a good opportunity to do longer springs.

My 69 has a narrow frame SOA that was moved out to accommodate the springs and Dana 44 's - that being said - how wide is the CJ7 frame? If you have the money have custom fab longer springs done up - if you enjoy FAB work and are on a budget make what you have work. Plus it is always more gratifying when ya do the majority yourself...

 

[cjhank]

My 69 has a narrow frame SOA that was moved out to accommodate the springs and Dana 44 's - that being said - how wide is the CJ7 frame? If you have the money have custom fab longer springs done up - if you enjoy FAB work and are on a budget make what you have work. Plus it is always more gratifying when ya do the majority yourself...

Unfortunatley I am about 3000 miles away from my jeep right now so I cant pull measurements. But I remember a measurement outside my springs in the front of 30".

 

[73CJ]

Do you really need to go SOA? How big are the tires you are trying to clear.

They can get so tippy. Soft springs can make that even worse.

Axle angles, caster issues and steering linkage issues. Plus?

 

[Jimbos76cj]

Few questions

#1 how big of a tire do you plan running. That plays a big role in what size or type of spring to run

#2 why can you not run your current springs.. I'm hoping your answer will be that it will be to tall. Soa and 4" springs will net you between 9-10" of lift and be very tippy.

#3 how do you plan to safely set up the steering.. Hopefully you have high steer knuckles on that Chevy axle

If it were me I'd look at stock yj springs with 2.5" front shackle hangers for tires 33-36"..

The center pins on almost all spring packs can be relocated to the other side by clamping the spring, undoing the nut on the back of the spring pack and moving the pin to the other side.

 

[cjhank]

Do you really need to go SOA? How big are the tires you are trying to clear.

They can get so tippy. Soft springs can make that even worse.

Axle angles, caster issues and steering linkage issues. Plus?

Do I need SOA probably not but the lift springs for spring under are way to stiff to get any decent flex. The angles and caster issues will be addressed before the new perches are welded on the rear I hope. I currently have a 4 inch spring under lift and I havent had any issues its just super narrow, stiff, and really tippy. No matter what i do it cant really get worse than my current set up. Oh and 35" tires but i may go bigger depending how my cleareance is after the soa.

 

[cjhank]

Few questions

#1 how big of a tire do you plan running. That plays a big role in what size or type of spring to run

#2 why can you not run your current springs.. I'm hoping your answer will be that it will be to tall. Soa and 4" springs will net you between 9-10" of lift and be very tippy.

#3 how do you plan to safely set up the steering.. Hopefully you have high steer knuckles on that Chevy axle

If it were me I'd look at stock yj springs with 2.5" front shackle hangers for tires 33-36"..

The center pins on almost all spring packs can be relocated to the other side by clamping the spring, undoing the nut on the back of the spring pack and moving the pin to the other side.

1. I plan on running a 35" with a maximum tire size of 37".

2. Oh ya way to tall. I would prefer to run a stock height spring off of a YJ or CJ but not sure what i will net there im thinking between 5" or 6".

3. I definitly am planning a high steer set-up. It wont be easy i am going to have to do some figuring on that. I have also seen the conversion that swaps the tie-rod to the rear of the axle makes things much simpler or so it seams.

I think the stock yj is what I will be looking for.

 

[csuengr]

I run 35" tires with 4.5" spring under lift (YJ springs) and 1" body lift. I have no problem with clearance or stability and it flexes just fine. The ride is also better than my dad's CJ with a 2.5" lift using CJ springs. Flex isn't everything. The more flex you have, the less stability you have. Unfortunately, there are still people out there who believe that a vehicles offroading ability is directly related to it's RTI score. The majority of a vehicles ability actually depends solely on who sits behind the wheel. Unless you are planing to exclusively do rock crawling, a spring over is an expensive solution to a problem that doesn't exist.

 

[Old Dog]

I'm also happy with my 4" sua lift but it's your money.
If you decide to go bigger than 35's you are going to need to up-grade to bigger axles IMO.

 

[CJ]

~~~ Unless you are planing to exclusively do rock crawling, a spring over is an expensive solution to a problem that doesn't exist.

Umm.... Yea...

 

[csuengr]

Thinking, if the OP has a Cheby axle, it already has perches for a spring over. Though I wonder if it is indeed a Dana 44 or a 10 bolt. 10 bolt fronts are as common as dirt while Cheby front Dana 44 's are kinda rare.

Another issue is lug nuts. The Cheby axle will have 7/16" studs while the Isuzu axle will have 12mm studs.

Rubicon express makes 1.5" lift springs just for spring overs. Though I have not been happy with my RE springs. I have seen 30 year old factory springs look better than mine, which are six years old. Half my friction pads are gone and I had to pull out a broken leaf last week.

 

[cjhank]

I run 35" tires with 4.5" spring under lift (YJ springs) and 1" body lift. I have no problem with clearance or stability and it flexes just fine. The ride is also better than my dad's CJ with a 2.5" lift using CJ springs. Flex isn't everything. The more flex you have, the less stability you have. Unfortunately, there are still people out there who believe that a vehicles offroading ability is directly related to it's RTI score. The majority of a vehicles ability actually depends solely on who sits behind the wheel. Unless you are planing to exclusively do rock crawling, a spring over is an expensive solution to a problem that doesn't exist.

Good for you I am not saying flex is everything I'm stating that an soa is going to be what I am doing that's not up for debate. I could care less what my rti score is I never plan on trying that. The point is I am spring under currently and I am not a fan. This jeeps getting axle up grades and the new axles aren't set up spring under and I am not going to make axles spring under that would be foolish when I can use stock yj springs get nice lift, nice ride and good off road capability.

 

[cjhank]

Thinking, if the OP has a Cheby axle, it already has perches for a spring over. Though I wonder if it is indeed a Dana 44 or a 10 bolt. 10 bolt fronts are as common as dirt while Cheby front Dana 44 's are kinda rare.

Another issue is lug nuts. The Cheby axle will have 7/16" studs while the Isuzu axle will have 12mm studs.

Rubicon express makes 1.5" lift springs just for spring overs. Though I have not been happy with my RE springs. I have seen 30 year old factory springs look better than mine, which are six years old. Half my friction pads are gone and I had to pull out a broken leaf last week.

Yes you are correct they have spring over perch. The 44 is pretty common but no where near as common as the 10 bolt was.

As for the studs what we did on my Buddy's Isuzu axle is we changed the studs to be the
same.

Sounds like I may need to take your advice on the springs and stick with stock. Thank you for the helpful advice.

 

[jdarg]

I have SOA on my trail rig YJ, using only stock, OEM springs for the past 3 years or so. Here's my experience.

It's not a "free lunch" except maybe on a street-only Jeep (in which case I'd just run the 4" springs, frankly - keep reading...)

The downside to stock springs offroad is that if you want any sort of decent flex you'll end up wearing out the springs quick. You must compress the springs past where they invert to get good flex. This inversion kills them in relatively short order. After a single season of wheeling, maybe 3-6 trips, they will all be flat - if not slightly inverted - at rest.

If you don't wheel, you can simply lower your bumpstops to the point where the springs can't invert. But that kills the flex advantage you spent all the time and money to gain.

Supposedly the purpose-made Rubicon Express SOA springs have less or no issues, but IMHO that's a lot more lift on top of the SOA. SOA will give you 5-6" depending on the spring perches you weld to the axles, stock being less, "high rise" quarter-inch steel ones from MORE, etc. netting you another 1-1.5" above that. When you figure in the cost of replacing all the springs, you start getting to the point where ditching the leafs is more cost effective and has less cons. I didn't go this route because I want to keep my YJ on leafs because that is the "essence" of a YJ IMHO.

I've personally been getting by by adding in an extra leaf after one season, either an AAL or a coupla leafs from some junkyard 2.5" springs w/ the eyes cut off, then replacing the whole leaf pack after the next season when those clap out. Rinse and repeat.

Axle wrap is also a huge issue. You'll NEED a traction bar setup in the rear (the wrap was really bad even when I had a lowly 4 cylinder in the engine compartment) , and the front too if you wheel it on "obstacles". These also limit flex at least a little if done right, more if done wrong.

I killed rear springs in short order without a rear bar w/ the 4 banger on just the street. Offroad I probably would have bound up and broke a rear driveshaft on the first trip. I actually have video on youtube where I drove around town w/ a webcam underneath the Jeep. I could get 30+ degrees of upward/downwarn pinion rotation accelerating from a stop or under moderate braking without even trying. I never see anyone mentioning spring wrap wrt braking buts is even worse than the issues under acceleration in an emergency stop situation.

Everyone has mentioned the other issues. High steer = needed, as well. The steering is also goign to limit your flex in the front - your tie rod ends up hitting either the frame or the leaf under compression/extension before the suspension is actually maxxed. All you can do is shoot for the middle at rest.

All this said, the Jeep does a respectible job offroad. It won't outflex even a mildly upgraded TJ on a ramp though. The ride on the street is absolutely great too, assuming your angles, etc. are all correct. There's a more sway without the sway bars around corners, but I wouldn't call it "tippy", and if it wasn't for the rear Detroit I'd say anyone can drive it and not feel like they are over their heads or that it feels unsafe.