2" Lift for LJ: Yet Another Spring Discussion

OldBuzzard

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I have a stock 2005 Unlimited (LJ) with a hardtop on 31-inch tires, as a daily city driver, with regular wheeling trips to the mountains when the weather allows. And I pull a heavy-ish trailer a few times a year. Yes, I'm trying to do 3 very different jobs with one vehicle.

I want to lift it 1.75 to 2 inches, keeping the 31-inch tires, to keep the street manners without too many alterations needed. No winch, no heavy bumpers, no plans for any. I would rather use springs than spacers, partly to replace the 16 year old OEM springs which are starting to sag a little in the rear. I read a lot of other discussions here, including Irun's "A Lesson Learned — Keep It Light And Nimble!". So I bought the H&R 52107 Sport Springs for 1" of lift, and planned to add some StreetRays 1" aluminum spacers, possibly turned down to a shorter height, to get the rest of the lift. But when I installed the rear H&R springs, the rear lift was exactly 0.0". Yes, I verified that I really did put the purple H&Rs in there :) I guess the rear weight of the Unlimited is a bit too much for the H&R springs. I didn't even bother to try the front springs, since it's clear that the rear ones are not going to work. I'm trying to work out a return with Tire Rack.

I understand that many "2-inch lift" springs will give a little more than 2 inches on a light TJ, and not so much on a heaver one. But there seems to be less real-world data on how they will act on an LJ. I really would like to limit the lift to about 2 inches. But with the old, possibly sagging springs, I don't even have a very good measurement baseline to start with. I ran a bunch of calculations on the Spring Rate, Free Height, and Install Height for the OME springs (Light 2932, Heavy 2933 for front, and Light/Medium 2941, Heavy 2942, Unlimited Heavy 2949 for the rear). But much of that is guesswork, too (weight of the rear corners of MY LJ, etc). That gave me a general notion of how the different springs will react, and somewhat of a ballpark of the lift I'll get (that's pretty vague, eh?).

So here's my question: From actual experience installing OME or other brand "2-inch lift" springs on a stock non-Rubicon LJ with a hardtop, how much lift did you get? And there's that trailer I want to pull. Yes, I know, that's a pretty narrow set of requirements. But just in case someone has this information . . .

Otherwise, I'll probably go with the "Stock/Light Load (0-90 lbs)" OME 2932 springs (2" lift) for the front, and the "Heavy Constant Load" OME 2942 springs (2" lift) at the rear. It doesn't have to be OME, it just seemed like they had a wider selection, and more data, for me to zero in on. It seems that lifting the Unlimited shifts all of the calculations a little.

Recommendations?
 
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CC782 Moog springs in the front will give you just over an inch and airbags in the rear will give you the other inch. Two inch lift doesn't give you a whole lot over one. One very important thing, if you run any fancy shock, Rancho X, 5100 or Fox you should go with the 2" and forget what I said. You need stock shocks up front to make the 1+" lift work, 4" up and 4" down. If you get Ranchos it'll be 3" up and 5" down and you'll hate me. Those "high performance" longer shocks need the full 2" lift to make up for their longer compressed length. Just something to consider, I run it with 32" tires and it's a great setup and my Jeep is really heavy.
 
I forgot to mention that I just installed Skyjacker Black MAX shocks. B8516 in front (good for 0" to 3" lift). B8508 in rear (good for 0" lift only). But I plan to add a shock bar pin eliminator, bringing the shock down 1 inch. That makes the B8508 have almost exactly the same compressed and extended dimensions as the Rancho RS55240 (0" to 2" lift).
 
I lifted my LJ recently and used the 2933 springs up front and the 2949 in the rear. I have a safari cab on it (heavy), an exogate, and a bike rack which stays on the rear tire. I got right at 2" of lift in the front (maybe a touch under). The stock rear springs were badly sagging so I didn't get a baseline measurements, but this setup gave me about 0.5" of rake front to back. I think if you have a hardtop and/or any significant weight in the rear of an LJ, the OME 2949 springs are ideal.
 
Unfortunately, the H&R springs are not ideal for an LJ, especially one running the factory hard top. I've had them on two vehicles (TJs) and they work great there, but only if weight is kept down. H&R previously sold a spring specific to the LJ, but that was discontinued awhile ago.

That said, @pagrey pointed out something that doesn't get discussed enough here. That is, the 2" springs really don't get you much over a 1" spring and introduce more challenges than they are worth. Yes, people do use them regularly, but few actually take the time to cycle the suspension and work through getting everything to play nicely together. Additionally, finding good shocks that give you a 50/50 bias for 2" springs isn't as easy as you would think.

I believe @MountaineerTom runs 2.5" OME springs on his LJ, with 31" tires. He doesn't have a hard top, but does run a heavier rear bumper. He also runs Black Maxx shocks. Perhaps he can chime in!
 
I do have all the stuff @Irun listed.

-31” tires
-OME front HD springs - 2933 Heavy Load (90 - 180 lbs)
-OME read HD springs - 2942 Constant Heavy Load (220 to GVW)
-Front Black Maxx shocks - B8516
-Rear Black Maxx shocks - B8518

-LOD signature series rear bumper with swing out tire carrier. The total weight of this thing with my spare tire (31” BFG mud terrain on an aluminum procomp wheel) is 174 lbs.
I don’t know How much a hardtop weights, but I would guess my bumper/tire carrier is close if not more than the the hard top.

Even with the HD springs up front, I had quite a bit of forward rake due to my LOD stubby bumper, Smittybilt winch plate and Warn VR8000 winch with steel cable. I added an additional spring isolator on top of the original which raised it up front to just slightly lower than the rear. The isolators measure right at 3/4”.

I think you would want the HD springs in the rear for sure. Especially with you’re trailer hooked up.

I’m not sure about the front. With everything OEM up front and no winch, I have a feeling you would have a lot of forward rake when you don’t have your trailer hooked up.

Here’s a few pictures from the last couple years of how it sits with these springs.

F58364E4-E21C-4F34-9FD8-18A127F61064.jpeg

7090A58D-36DA-4C0C-97E8-83E96FBA7003.jpeg

E9490B14-05C6-4ABF-A1BD-088974A91D36.jpeg
 
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I was planning on 1.5" to 2" lift, which is why I started with the 1" H&R springs. And I was going to get some 1" aluminum spacers and turn them down on a lathe to whatever thickness I needed. When the H&Rs didn't work out, I decided to shoot for a 2" spring lift. I could still do the custom spacers to trim it up if needed.

I ordered the springs and a few other parts today. With no extra load on the front, and no plans to add any, I went for the OME 2932 "Stock/Light Load (0-90 lbs)" springs. And the OME 2942 "Heavy Constant Load" at the rear. I had looked at their 2949 "UNLIMITED Heavy Constant Load" springs, but they seem too stiff for a daily driver with only occasional trailer weight.

Once I get them installed to know the ride height, I'll cycle the suspension to figure out the bump stops and shocks (I learned that from you guys). I already have new Black MAX shocks, and a bar pin eliminator will move the rear (B8508) down an inch. That shouldn't be too bad, although if I had bought the B8518 I would have gotten more travel.

And I have a set of Air Lift balloons which I used previously to level the Jeep when pulling the trailer. Next spring I'll put those back in, with an extra spacer to fill the lift gap. They've done a great job, but I don't fully trust them. They hold air nicely for months (I check weekly), and then one day they don't. And then they do again. That only happened once, but...

Thanks for the input, everyone, this really helps. I've been following some of your builds (Irun, MountaineerTom), and there is a LOT of good information being shared here.
 
I was planning on 1.5" to 2" lift, which is why I started with the 1" H&R springs. And I was going to get some 1" aluminum spacers and turn them down on a lathe to whatever thickness I needed. When the H&Rs didn't work out, I decided to shoot for a 2" spring lift. I could still do the custom spacers to trim it up if needed.

I ordered the springs and a few other parts today. With no extra load on the front, and no plans to add any, I went for the OME 2932 "Stock/Light Load (0-90 lbs)" springs. And the OME 2942 "Heavy Constant Load" at the rear. I had looked at their 2949 "UNLIMITED Heavy Constant Load" springs, but they seem too stiff for a daily driver with only occasional trailer weight.

Once I get them installed to know the ride height, I'll cycle the suspension to figure out the bump stops and shocks (I learned that from you guys). I already have new Black MAX shocks, and a bar pin eliminator will move the rear (B8508) down an inch. That shouldn't be too bad, although if I had bought the B8518 I would have gotten more travel.

And I have a set of Air Lift balloons which I used previously to level the Jeep when pulling the trailer. Next spring I'll put those back in, with an extra spacer to fill the lift gap. They've done a great job, but I don't fully trust them. They hold air nicely for months (I check weekly), and then one day they don't. And then they do again. That only happened once, but...

Thanks for the input, everyone, this really helps. I've been following some of your builds (Irun, MountaineerTom), and there is a LOT of good information being shared here.

Turning the aluminum spacers to suit your needs sounds like a good plan. I agree, that those 2949 springs would be too much for every day use considering the rear of your setup.

Keep us updated. 👍
 
I was planning on 1.5" to 2" lift, which is why I started with the 1" H&R springs. And I was going to get some 1" aluminum spacers and turn them down on a lathe to whatever thickness I needed. When the H&Rs didn't work out, I decided to shoot for a 2" spring lift. I could still do the custom spacers to trim it up if needed.

I ordered the springs and a few other parts today. With no extra load on the front, and no plans to add any, I went for the OME 2932 "Stock/Light Load (0-90 lbs)" springs. And the OME 2942 "Heavy Constant Load" at the rear. I had looked at their 2949 "UNLIMITED Heavy Constant Load" springs, but they seem too stiff for a daily driver with only occasional trailer weight.

Once I get them installed to know the ride height, I'll cycle the suspension to figure out the bump stops and shocks (I learned that from you guys). I already have new Black MAX shocks, and a bar pin eliminator will move the rear (B8508) down an inch. That shouldn't be too bad, although if I had bought the B8518 I would have gotten more travel.

And I have a set of Air Lift balloons which I used previously to level the Jeep when pulling the trailer. Next spring I'll put those back in, with an extra spacer to fill the lift gap. They've done a great job, but I don't fully trust them. They hold air nicely for months (I check weekly), and then one day they don't. And then they do again. That only happened once, but...

Thanks for the input, everyone, this really helps. I've been following some of your builds (Irun, MountaineerTom), and there is a LOT of good information being shared here.
Got an update on how this went? I have the exact same Jeep and was looking at the 2933 for the front and 2942 for the rear.
 
Short update for now, more later: I got the 2932 front and 2942 rear OME springs. A temporary installation of the rear springs shows they'll lift it about 1-5/8" or 1-3/4". After cycling the rear suspension for measurements, the springs are back out now while I make some bump stop extenders and get longer shocks. Hopefully I'll get the rear end finished in a couple of days and then move to the front.