Rockjock (Currie) front spring updates

[freedom_in_4low]

I got the 9132FP that they now list as 5" for my LJ. It came out close enough to 4" to not care about the difference. I have Savvy rocker guards, a 1/4" steel belly skid, a warn stubby bumper and a winch on the front. I would use the same springs on any LJ that has any weight above bone stock.

 

[notnsuv]

Yes, installed length. I believe that 4.25 or so is corr

I got the 9132FP that they now list as 5" for my LJ. It came out close enough to 4" to not care about the difference. I have Savvy rocker guards, a 1/4" steel belly skid, a warn stubby bumper and a winch on the front. I would use the same springs on any LJ that has any weight above bone stock.

Wahoo! Confirmation.

 

[g.hayduke]

I got the 9132FP that they now list as 5" for my LJ. It came out close enough to 4" to not care about the difference. I have Savvy rocker guards, a 1/4" steel belly skid, a warn stubby bumper and a winch on the front. I would use the same springs on any LJ that has any weight above bone stock.

Any ideas what your rig actually weighs? Are you running a soft top or hard top?

What springs are you running in the rear?

I have a LJ that I'm looking to put a 4" lift under but it's heavy, close to 5Klbs when loaded for a trip. Sounds like those front springs might work but my back end is heavy. I have a Tuffy drawer unit that fits behind the back seat with all my tools and such in it. Not the ideal location but I'm not doing any super-challenging terrain.

 

[starkey480]

Lol just to reiterate. The CE-9132FP are still the same desired front springs as always. Rockjock relabeling them from 4” to 5” lift springs on their website hasn’t changed how much lift they will give your Jeep. They only changed the name because some people complained they were getting more than 4” of lift.

To show how meaningless the labels are, my lift height changed 1/4” by just changing from steel to synthetic winch line. Rockjock doesn’t know what kind of winch line I have.

 

[starkey480]

Any ideas what your rig actually weighs? Are you running a soft top or hard top?

What springs are you running in the rear?

I have a LJ that I'm looking to put a 4" lift under but it's heavy, close to 5Klbs when loaded for a trip. Sounds like those front springs might work but my back end is heavy. I have a Tuffy drawer unit that fits behind the back seat with all my tools and such in it. Not the ideal location but I'm not doing any super-challenging terrain.

If you’re looking for roughly a 4” lift on an LJ I would go with these:
Front springs CE-9132FP
Rear springs CE-9131RH3P

 

[freedom_in_4low]

Any ideas what your rig actually weighs? Are you running a soft top or hard top?

What springs are you running in the rear?

I have a LJ that I'm looking to put a 4" lift under but it's heavy, close to 5Klbs when loaded for a trip. Sounds like those front springs might work but my back end is heavy. I have a Tuffy drawer unit that fits behind the back seat with all my tools and such in it. Not the ideal location but I'm not doing any super-challenging terrain.

The explanation takes a little bit of backstory.

I bought a TJ with unidentified 3" lift springs. I added 3/4" spacers all around. It weighed about 4000-4100 pounds. I decided I wanted an LJ, so I bought one, moved all my axles, suspension, bumper and winch over to it, and then sold the TJ.

Once I got the LJ on it's own weight, the front end was sitting lower than it did on the TJ...like 3/4" lower. I didn't like that, so I bought the RJ 4" springs for the front, and it got back to where the other springs were on the TJ. I've never weighed the LJ, but since it's got all the same mods, it should be close to what the TJ weighed plus whatever 15" of frame, tub, carpet, top, and roll bar plus 10" of driveshaft adds up to. It has a soft top.

So I'm still running the unidentified 3" springs plus 3/4" spacers in the rear, and based on my observation, the additional weight going from TJ to LJ lands more in the front than the rear.

 

[g.hayduke]

If you’re looking for roughly a 4” lift on an LJ I would go with these:
Front springs CE-9132FP
Rear springs CE-9131RH3P

What is the weight of this hypothetical LJ for which these springs are appropriate and will yield a 4" lift?

When I called RockJock, they said they had no springs that would yield 4" lift on a 5Klb LJ.

Based on this thread, it sounds like those CE-9132FP front springs might be good. The front of an LJ weighs pretty close to the front of a TJ. However, the back end of my LJ is no way comparable to the back end of a typical TJ weight-wise.

What surprises me is how few discussions of springs and lift height mention the actual weight of the rig. Our rigs vary widely and with any given spring, the vehicle weight determines the actual lift height (not including the weight of the axles, tires, etc.).

Aluminum vs steel bumpers and armor; hard top vs soft top. TJ vs LJ, 4cyl vs 4.0; etc., etc. make a huge difference in the weight and lift height. It's weird how seldom actual vehicle weight is part of the conversation.

 

[g.hayduke]

based on my observation, the additional weight going from TJ to LJ lands more in the front than the rear.

Really? I guess I can see a little more weight on the front from more of the TC weight on the front as you move the rear axle back. Maybe that explains it. I suspect most of the hard top weight is on the rear axle since the glass is the heaviest part.

 

[starkey480]

What is the weight of this hypothetical LJ for which these springs are appropriate and will yield a 4" lift?

When I called RockJock, they said they had no springs that would yield 4" lift on a 5Klb LJ.

Based on this thread, it sounds like those CE-9132FP front springs might be good. The front of an LJ weighs pretty close to the front of a TJ. However, the back end of my LJ is no way comparable to the back end of a typical TJ weight-wise.

What surprises me is how few discussions of springs and lift height mention the actual weight of the rig. Our rigs vary widely and with any given spring, the vehicle weight determines the actual lift height (not including the weight of the axles, tires, etc.).

Aluminum vs steel bumpers and armor; hard top vs soft top. TJ vs LJ, 4cyl vs 4.0; etc., etc. make a huge difference in the weight and lift height. It's weird how seldom actual vehicle weight is part of the conversation.

If your Jeep is that heavy, then the same spring recommendation still applies since those are their longest springs. If you still want more lift then just add a small spacer.

Talking about all the gear and stuff you have on the rig to compare lifts you get from springs seems a bit silly considering how different each persons combinations are. If you truly want to find out exactly how much lift you’re going to get then just do the math on the free length and spring rate of your current setup and then do the math with the free length and spring rate of the perspective springs and you can find out exactly how much lift you’ll get.

 

[jjvw]

Lol just to reiterate. The CE-9132FP are still the same desired front springs as always. Rockjock relabeling them from 4” to 5” lift springs on their website hasn’t changed how much lift they will give your Jeep. They only changed the name because some people complained they were getting more than 4” of lift.

To show how meaningless the labels are, my lift height changed 1/4” by just changing from steel to synthetic winch line. Rockjock doesn’t know what kind of winch line I have.

And to further add to the meaninglessness, if the rear end is stupid heavy past the axle the front end will lift up.

 

[g.hayduke]

If you truly want to find out exactly how much lift you’re going to get then just do the math on the free length and spring rate of your current setup and then do the math with the free length and spring rate of the perspective springs and you can find out exactly how much lift you’ll get.

Seems that you put a lot more faith in the manufacturer specs than I do.

And calculating anything based on my old 2" lift springs seems like a pretty silly approach to me.

If I know what a somewhat comparable rig weighs and what springs they are using to get a roughly 4" lift, I'll weight that information much more heavily than some theoretical calculations. I'm trying to buy 1 set of springs that will do what I want.

I'm fine with doing a calculation when I have some confidence that the values plugged into the variables are close to correct and the equation is solid. Otherwise, garbage in, garbage out.

 

[jjvw]

Seems that you put a lot more faith in the manufacturer specs than I do.

And calculating anything based on my old 2" lift springs seems like a pretty silly approach to me.

If I know what a somewhat comparable rig weighs and what springs they are using to get a roughly 4" lift, I'll weight that information much more heavily than some theoretical calculations. I'm trying to buy 1 set of springs that will do what I want.

I'm fine with doing a calculation when I have some confidence that the values plugged into the variables are close to correct and the equation is solid. Otherwise, garbage in, garbage out.

I did the math on several sets of OME coils where the rates and lengths are published. It was always close enough to make a good enough prediction.

 

[freedom_in_4low]

Seems that you put a lot more faith in the manufacturer specs than I do.

And calculating anything based on my old 2" lift springs seems like a pretty silly approach to me.

If I know what a somewhat comparable rig weighs and what springs they are using to get a roughly 4" lift, I'll weight that information much more heavily than some theoretical calculations. I'm trying to buy 1 set of springs that will do what I want.

I'm fine with doing a calculation when I have some confidence that the values plugged into the variables are close to correct and the equation is solid. Otherwise, garbage in, garbage out.

if you're more worried about the final ride height than the absolute most travel you can get, it may make sense to buy someone else's springs. By definition, Rockjock springs, as the longest free length, will be the lowest rate, so they will experience the highest degree of variation between rigs of different weights. The opposite would be a high rate with a short free length.

 

[notnsuv]

if you're more worried about the final ride height than the absolute most travel you can get, it may make sense to buy someone else's springs. By definition, Rockjock springs, as the longest free length, will be the lowest rate, so they will experience the highest degree of variation between rigs of different weights. The opposite would be a high rate with a short free length.

Like these for instance? From an online search for spring rate of my current RE 4.5". The RJ 70# x 22.6". Huge difference.

From Rubicon Express customer service email to T.N. (November 2004):

The 3.5" TJ fronts are approximately 240 pounds per inch. Uncompressed free
length is 19"

The 4.5" TJ fronts are approximately 219 pounds per inch. Uncompressed free
length is 19.75"

 

[freedom_in_4low]

Like these for instance? From an online search for spring rate of my current RE 4.5". The RJ 70# x 22.6". Huge difference.

From Rubicon Express customer service email to T.N. (November 2004):

The 3.5" TJ fronts are approximately 240 pounds per inch. Uncompressed free
length is 19"

The 4.5" TJ fronts are approximately 219 pounds per inch. Uncompressed free
length is 19.75"

Exactly.

The Rockjock springs will sit an inch different on two rigs that have 140 pounds difference between them on the front axle. Those 4.5" RE springs could take over 400 pounds difference to make that much change in ride height.

Whether or not it's intentional, it reflects a different philosophy between the two companies. Rockjock is trying to produce a spring with the best travel potential including rigs with midarms and shock relocations at the cost of variability in ride height results, while RE is trying to produce a spring that provides the most consistent ride height regardless of the rig configuration, at the cost of needing spring retainers to keep the coils from falling out when paired with anything as long or longer than an 11" Rancho.

 

[jjvw]

Like these for instance? From an online search for spring rate of my current RE 4.5". The RJ 70# x 22.6". Huge difference.

From Rubicon Express customer service email to T.N. (November 2004):

The 3.5" TJ fronts are approximately 240 pounds per inch. Uncompressed free
length is 19"

The 4.5" TJ fronts are approximately 219 pounds per inch. Uncompressed free
length is 19.75"

Look in the resources section for a long list of spring specs.

 

[g.hayduke]

if you're more worried about the final ride height than the absolute most travel you can get, it may make sense to buy someone else's springs.

I wouldn't say I'm worried about ride height. However, I need about 4" to clear 35s and I don't want to end up much higher than that for all the well-known reasons. Call it worry or whatever you want but that is my design goal.

I don't expect to find RockJock springs for the back of my rig. THIS thread is primarily about front springs. And the front springs that are the topic of this thread might be just about perfect for MY purposes. Hence, my questions.

 

[csaxj3]

4" Savvy here, front was a little higher stock but added bumper, skids, winch, and all worked out.

They flex well.

 

[freedom_in_4low]

I wouldn't say I'm worried about ride height. However, I need about 4" to clear 35s and I don't want to end up much higher than that for all the well-known reasons. Call it worry or whatever you want but that is my design goal.

I don't expect to find RockJock springs for the back of my rig. THIS thread is primarily about front springs. And the front springs that are the topic of this thread might be just about perfect for MY purposes. Hence, my questions.

worried, concerned, focused, prioritized...whatever word feels right is fine with me. I was just trying to say that if ride height is more important than max travel, then a shorter free length and heavier rate spring may be the logical choice in your case. If you think you'd like the travel, I'd just go with rockjock and go in with the expectation that you may end up adding a coil spacer to get the ride height you want.

 

[g.hayduke]

I was just trying to say that if ride height is more important than max travel, then a shorter free length and heavier rate spring may be the logical choice in your case.

Like anybody else, I want the maximum travel I can get within the limitations of a 4" lift. But travel is a different topic.

I don't need springs right now. My new lift has a few things in line ahead of it.

I was working on an awesome manual locking hub conversion. That got preempted by a sudden urgent need to replace my transmission. Before I got that all back together, I tore my rotator cuff and had shoulder surgery 5 weeks ago. So the lift is down the road a piece.

Threads like this are just part of my research.

For now I can't do shit, really.