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Discussion Starter · #1 ·
Ok, I have "searched my a$$ off and can't find the answer to my specific questions. Below are my JK's specs, and what I'm trying to figure out:

-Specs:
--2012 JKU Rubicon
--AEV Front Bumper / Warn 9.5cti-s
--AEV Rear Bumper / Tire Swing / Fuel Caddy
--OEM Suspension

-What I would like to figure out:
--Lift by 1-2" with stiff springs only, and keep close to the factory rake (I like the way it looks)
--Avoid spacers, if possible (I bought the AEV spacer lift, but it's still in the box)
--Tereflex 1.5 kit won't work for a JKU Rubicon (already called and verified from Tereflex that the kit is not intended for Rubi's, and won't do it)

On another note, I have absolutely no interest in ever going over 33's. I am very firm on that, and do not want a 2.5" lift, just enough to clear 33's without harming performance on and off-road. I'm not worried about regretting only getting 1-2", and not going with a larger lift.

I assume all I need is to find the right spring combination, which has been very challenging for me. The search button has not helped. Thanks in advance!!!
 

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That's gonna be a tall order; not because it's impossible...it's just gonna be tough to find the perfect spring combo.

Why not spacers? They won't impede your performance at all, although they also won't prevent your current springs from sagging, either. That would be the simplest, and cheapest, way to go. And if your springs sagged a little more over time, or if you felt you were too high, you could add or subtract to keep your Jeep where you want it.

And why won't the TF leveling kit work with the Rubi? Are you talking about the spacer kit or the spring kit? Seems like either would work...

As for spring lifts, in most cases they're gonna wipe out your factory rake. I don't know of any in which the mfr built into em the ability to retain rake. It's gonna be like finding two matching buttons in a barrel of castoff buttons.
 

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Discussion Starter · #4 ·
That's gonna be a tall order; not because it's impossible...it's just gonna be tough to find the perfect spring combo.

Why not spacers? They won't impede your performance at all, although they also won't prevent your current springs from sagging, either. That would be the simplest, and cheapest, way to go. And if your springs sagged a little more over time, or if you felt you were too high, you could add or subtract to keep your Jeep where you want it.

Well, it's looking more and more like I will have to use spacers, but I didn't want to because I have read it's better to go with springs. I wish I had a better answer, but I'm not very educated in the art of suspensions :confused:.

I think another option would be to use the same springs the 2012 MW3s use, but I haven't found out which spring rate they are. I guess I wouldn't mind adding 1" spacers in the front and rear with the MW3 Springs. In addition, I'm not even sure what springs I have on my JKUR because I'm stationed overseas. I'll have to have my wife take a look for me. I will be back in Dec, but I wanted to install this stuff when I get back, and will only have 3 weeks before I leave for another 6 months.

And why won't the TF leveling kit work with the Rubi? Are you talking about the spacer kit or the spring kit? Seems like either would work...

That's what the Tereflex Rep told me. He said the kit wasn't designed for Rubicon's, I'd end up with the same situation

As for spring lifts, in most cases they're gonna wipe out your factory rake. I don't know of any in which the mfr built into em the ability to retain rake. It's gonna be like finding two matching buttons in a barrel of castoff buttons.
Replies in red.
 

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Discussion Starter · #5 ·
Ok....had my wife look under the Rubi at my springs.
They are:
Front: 52126318ac
Rear: 68004459aa
 

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Discussion Starter · #6 ·
Also, could stiffer shocks play a part in this? What I mean is, are shocks able to provide any kind of height difference, or are shock irrelevant when it comes to that? Again, I'm a moron when it comes to suspension.

I'm considering returning my AEV 2" spacer kit, going with the 19/60 Mopar springs, and 1" spacers, unless shocks may play a part. Am I mad???
 

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I dont know why the Teraflex Performance leveling kit wouldnt work for you.This is what i have and the springs that come in this kit were alot beefer and have more coils then what the stock springs were.You also get about 1.5-2" of lift and looks like thats exactly what your looking for.My 2012 Sport had the 17/59 springs in it before swapping them to the ones that came with the Teraflex performance leveling kit.I still have the factory shocks on it,,,,didnt need to change them with this kit.
 

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Teraflex spacer kit will work fine on your Rubicon. I had one on my '12 JKUR. If you think the spacers are too thick you can use a belt sander and take them down to the height you want as they are just a hard rubber. Daystar makes some thin spacers ov varying thickness.
 

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Ok....had my wife look under the Rubi at my springs.
They are:
Front: 52126318ac
Rear: 68004459aa
Okay, so your springs are 18 up front (out of a possible 19) and 59 in rear (out of 60). So a spring swap will do nothing for you.

Also, could stiffer shocks play a part in this? What I mean is, are shocks able to provide any kind of height difference, or are shock irrelevant when it comes to that? Again, I'm a moron when it comes to suspension.

I'm considering returning my AEV 2" spacer kit, going with the 19/60 Mopar springs, and 1" spacers, unless shocks may play a part. Am I mad???
Stiffer shocks will give you a stiffer ride. Longer shocks will give you more down travel.

Forget the 19/60 springs. You'll see no difference btw those and the 18/59's you've already got. Best bet, IMO, is gonna be to install a leveling kit. Either the straight TF leveling kit, or the TF spring leveling kit. Difference in price, however, is about $300.

BTW, both will fit your Rubi. Don't know why the TF would tell you they won't.

Personally, I think the $130 leveling kit would give you what you want, although it would eliminate your Jeep's rake. It comes with 4 (1") spacers up front, and 2 (1") spacers rear, plus a pair of longer sway bar links. If you're dead set on keeping the rake, you could always leave 2 of the 1" spacers off the front install, in which case you'd be raising your Jeep about 1" total.

Or you could keep the AEV spacer lift you've got. That'll raise you a little higher, and will eliminate the rake, as well.
 

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@ Spesrf, re: Shocks -

No, shocks do not change your ride height...basically, they are passive members of your suspension. They damp your springs/suspension response. The spring's rate will determine how much it compresses and it's free length will determine what you have leftover after that compression. That, then, will determine your static ride height, compression and extension available to your suspension.

If you want to be zealous, put your Jeep on a scale and get the weight on your front wheels and rear wheels as well your overall weight. Compare that to what your Jeep weighed when it rolled off the line and note the difference. New shocks will certainly help control the ride of a heavier Jeep (or a stock one, for that matter), but beefier springs will facilitate a more balanced ride over all.

I bitched a bit at some point about the fact that a lot of suspension folks do not make their stats available...well, I found at least one that does and sometimes vendors will help out. If you have the interest, you can compare spring rates and lengths of potential lifts versus stock you can figure out what you need to buy to end up where you want to be.

Folks make the mistake of equating static ride height and lift height because the former is used to categorize the latter. Let us assume your JK front coil is 18 inches. If you get a 20.5 inch coil to replace it, your suspension will have 2.5 inches more potential droop. The limiting factor will be your shocks in terms of travel - if the springs out droop the shocks you'll need limiting straps or longer shocks. Even that 2.5 inch longer spring will likely compress more than your stock length shock (unless you get some odd ball with uber thick coils), so your stock bumpstops and shock will remain the limiting factor there as well. So, end result is that a matched coil and shock combination will increase your overall suspension travel. The "lift" comes from the fact that when you have a longer free length, the static load height of the spring is likely to be a bit higher as well. However, increase in static ride height (the means folks often use to try and categorize a lift) is the by product, generally, more so than the goal.

That's how you end up with a advertised 2.5" lift giving you a reported 4+". The free length of the spring might indeed by 2.5 inches longer...however, if the spring rate increases significantly, the spring will compress less. So, 2.5 inches of free length PLUS the difference in compression will be the change in static ride height. That's why it is important to match the proper spring rate with your intended use. Ideally, you probably want your Jeep somewhere in the middle of the over all travel. A too stiff spring is going to be uncomortable and degrade control both on road and off by giving your Jeep an unnecessarily high center of gravity and interfering with effective uptravel/compression. A too soft spring is going to limit your compression and ride rough at speed on road and off as your suspension "bottoms out" over high speed inputs.

In terms of your tire size - your shocks, bump stops, springs and fender/body clearance at full compression determine what your max tire size is and it is not directly related to free length and max shock extension or overall suspension travel. That's why you can clear 35s with either spacers/BB or a small lift or a fender chop.

So, the questions is, what do you want your suspension change to do? Give you more travel? Give you more ground clearance at static load? Give you a more effectively controlled or more comfortable ride?

If all you want is space for 33" tires - wheel spacers will do that for fatties and if you have issues at "full stuff" it's time for a little longer bump stop or fender chop. No real need to mess with suspension at all. However, if you need to go for a bigger bump stop to eliminate rubbing, it makes sense to match your shocks to your bump stop length to maximize shock travel...and you might want to take a look at updating your springs as part of a cohesive system. That's my semi-solicited advice...

I typed that while at work...so I am not sure on flow...I got disjointed there...
 

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Just for your peace of mind:

2013 Rubi w/TF leveling kit:



On a 2012:



On a 2007:



Before and after on a '12 (non-Rubicon):






2" AEV leveling kit (which I believe you have):


TF leveling kit on another '12:
 

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Discussion Starter · #12 ·
@ Spesrf, re: Shocks -
So, the questions is, what do you want your suspension change to do? Give you more travel? Give you more ground clearance at static load? Give you a more effectively controlled or more comfortable ride?
That was one good explanation. I appriciate it. I guess what I would like to do is:

-Keep close to factory look (why I chose the AEV bumpers)
-Keep a functional Jeep....I don't off-road often, but it's important to me for the Rubicon to function as intented.
-Add a little bit of height for ground clearance and the ability to add 33s in the distant future when I need to change tires
-Not change a ton of suspension/gears/etc.
-Keep the back from being lower than the front, again I like the factory rake. I assume that it will be similar after the springs/spacer kit/ or whatever I do, because I'm adding the AEV bumper and Warn winch.

If just adding the AEV spacers will not hinder the off-road performance, I guess I'll stick with them. I just want to be sure before I install them, and while I still have time to return them, if necessary.
 

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If you're satisfied with the stock suspension's performance, spacers are a convenient option as they'll leave that performance intact and give you a very precise increase in ride height. Their simplicity helps minimize the odds of unanticipated complications and because you know how much height you're adding, you can preserve the ride height relationship between the front and rear of the vehicle.

One of the gents on this forum runs a 2" spacer on his 2-dr Rubicon with 35" tires and doesn't have any complaints I know of. He did cut his fenders as well.

If you're concerned about handling the extra weight you're getting more into the realm of shocks and spring upgrades...a spacer and a spring can be used together of course. The trick will be finding a spring that works for you.

As an example - If the stock spring height is ~18 inches (457 mm) and rate is 120 lb/in then...505 mm is about 2 inches longer (19.9 inches). If the weight on the front wheels is 2200 lbs (1100 lbs each), and the spring rate indeed 120 lb/in you'll note that's about 9 inches of compression...almost exactly half the stock spring's free height. You could raise the static ride height two inches by changing the spring rate to 160 lb/in (terrible idea, by the way).

Now, if you take that 505 mm, 120 lb/in spring and add 200 lbs of bumper and winch to the front of your Jeep, what do you get? To make the math easier, an extra 100 lbs per spring. With 1200 lbs per spring you'll now get 10 inches of compression or what folks refer to as 1" more "sag". If you had a 505 mm spring to start with, that would still leave you about an inch higher than a stock spring at stock weight ( 9.9" v. 9" and about half way through your spring's tavel) and you could declare victory...though your shock's might be a bit on the short side.

Alternatively, you might opt for, say, 490mm long spring (about 1.5 inches longer than stock - 19.3 inches) with a slightly stiffer rate - say 135 lb/in. Now, with that same 1200 lbs from above on the spring it will compress ~ 8.9 inches and sit about 10.4 inches high. So, the stiffer spring will actually end up sitting just a bit higher (~.5 in) than example above (and 1.5 higher than stock height, stock weight but WITH the bumper + winch) despite its shorter free length and will give you a taughter ride.

The trick then is figuring out which combination of length and rate gives you what you want - my thoughts? If you KNOW how much weight you're going to run, that makes it a LOT easier, thus my earlier suggestion to weigh it out how you'll kit it out. Then you can make an informed decision about which springs to run.

Again, as an example, OME makes the following part numbers for the JK front suspension (part #, free length in mm, spring rate in lb/in) ALL of which are intended for use as part of their 2" lift in different applications:
2615, 510 mm, 120 lb/in
2616, 490 mm, 135 lb/in
2619, 515 mm, 135 lb/in
2626, 500 mm, 120 lb/in
2627, 475 mm, 135 lb/in
2628, 505 mm, 135 lb/in
2629, 505 mm, 150 lb/in.

So, you can see how folks can easily pick a spring that gives them far too much increase in static ride height with even a modest increase in rate and free height. That's what makes spacers so easy in comparison. I would be willing to be that a 1" space and a 1.5-2" spring intended for an unloaded JK 2-dr would probably put you out at around 2" for a 4-dr with winch and bumper...though it likely wouldn't improve your handling any if that were a concern.

A quick look around shows at least 17 folks that make springs for the JK and I'm probably missing a few.
 
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