How much lift does a rubicon spring / shock give?

[Huskies91]

newbie here... I searched for an answer first. Is it subjective or is there an estimated formula to determine amount of lift? I currently have springs 88/89 in rear and 58/59 up front on a 2020 JLU Willys. hard top/tow package/plastic bumpers. Just bought 91/92 r springs and 61/62 f springs. So a 3 number jump. Came off steel bumper/hard top/tow package. Assuming and hoping 1-1.5 inches. thanks...

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[chevymitchell]

newbie here... I searched for an answer first. Is it subjective or is there an estimated formula to determine amount of lift? I currently have springs 88/89 in rear and 58/59 up front on a 2020 JLU Willys. hard top/tow package/plastic bumpers. Just bought 91/92 r springs and 61/62 f springs. So a 3 number jump. Came off steel bumper/hard top/tow package. Assuming and hoping 1-1.5 inches. thanks...

You'll get about 1.5 -2"

 

[The Fixer]

You'll get about 1.5 -2"

I agree. I used the set below the one you picked up (60/61, 90/91) on my 2-door base Sport and got right around 2". Seems that with the even taller kit on a 4-door it should be close to 2".

 

[av8or]

You'll get about 1.5 -2"

What he said.

 

[ItsNo4RE]

The Willys already sits as high as the rubicon... at least the diesel versions sit as high as the diesel rubicons

 

[Huskies91]

Thanks everyone... Kind of what I anticipated. About 1.5 inches, maybe two. I'll post before and after and take measurements for my benefit, and for anyone that may bump up 3 numbers on springs in the future.

 

[blnewt]

Thanks everyone... Kind of what I anticipated. About 1.5 inches, maybe two. I'll post before and after and take measurements for my benefit, and for anyone that may bump up 3 numbers on springs in the future.

Look forward to your results, seems like 4drs get from 1.25 to 1.75" and the 2drs about a 1/2" more from the same spring#s.

Did you get the longer LCAs too??

 

[Huskies91]

I did not. Still on the fence. I probably just should but will see how it rides without first. If needed, I'll just order a set.

Did you get the longer LCAs too??
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[Huskies91]

I put the rubicon springs on this past weekend. I had 88/89 in rear and 58/59 up front prior to install and put on 91/92 r springs and 61/62 f springs. So a 3 number increase on all springs. I got about 1.5 inches on back and 1.25 up front of lift. Springs and coils had about 3k miles on them.

I did NOT install the longer Mopar LCAs and it feels like its driving exactly the same. Possibly because lift was not that much? I did not do an alignment and it's driving straight, no pulling either to the left or right. As for the drive quality, no discernible difference in driving characteristics that I could tell.

Picture below is after install. I have 295/75r18 tires. They measure 33.9 inches.

 

[a23persaud]

I put the rubicon springs on this past weekend. I had 88/89 in rear and 58/59 up front prior to install and put on 91/92 r springs and 61/62 f springs. So a 3 number increase on all springs. I got about 1.5 inches on back and 1.25 up front of lift. Springs and coils had about 3k miles on them.

I did NOT install the longer Mopar LCAs and it feels like its driving exactly the same. Possibly because lift was not that much? I did not do an alignment and it's driving straight, no pulling either to the left or right. As for the drive quality, no discernible difference in driving characteristics that I could tell.

Picture below is after install. I have 295/75r18 tires. They measure 33.9 inches.

Hey, how’s this setup holding up? I’m looking to do a Rubicon spring swap on my ‘21 Willys as well. Did you end up ever installing the longer LCA’s?

Also, would you mind explaining why the longer LCAs would be necessary for a spring swap and why people on some Forums are going that route?

thanks!

 

[blnewt]

Also, would you mind explaining why the longer LCAs would be necessary for a spring swap and why people on some Forums are going that route?

thanks!

As you increase front spring length you decrease caster about .75 to 1 degree per inch of lift. The JLs really like caster in the 6 to 7 degree range to keep tracking straight at hwy speeds. If you get caster below 5 degrees they are prone to wander on the hwy. The Rubicons come w/ the same LCAs as the other JLs and their caster is in the mid to low 4s, and most have problems w/ high speed wander until they add the longer LCAs.
When you swap to Rubicon springs your JL will also have the low Rubicon caster, luckily it's a cheap (about $80) and easy fix.
Here's my install post on them
https://www.jlwranglerforums.com/forum/threads/rubicon-suspension-on-2-door-sport.40700/#post-919317
And an epic thread with all the happy JL drivers after doing this simple "fix"
https://www.jlwranglerforums.com/forum/threads/mopar-lca-swap.22474/

 

[a23persaud]

As you increase front spring length you decrease caster about .75 to 1 degree per inch of lift. The JLs really like caster in the 6 to 7 degree range to keep tracking straight at hwy speeds. If you get caster below 5 degrees they are prone to wander on the hwy. The Rubicons come w/ the same LCAs as the other JLs and their caster is in the mid to low 4s, and most have problems w/ high speed wander until they add the longer LCAs.
When you swap to Rubicon springs your JL will also have the low Rubicon caster, luckily it's a cheap (about $80) and easy fix.
Here's my install post on them
https://www.jlwranglerforums.com/forum/threads/rubicon-suspension-on-2-door-sport.40700/#post-919317
And an epic thread with all the happy JL drivers after doing this simple "fix"
https://www.jlwranglerforums.com/forum/threads/mopar-lca-swap.22474/

Hey Bl,

I’m going to be doing the spring swap in the next couple of weeks on my 2021 Willys JLU. I read your post and have learned a lot, so thank you!

I think I’ll go the same route as you and install the longer LCAs at the same time to improve the caster.

The one thing I’m still uncertain about is adding spacers. Is this something I need to do? If I plan to add a steel bumper in the future, is it a good idea to add spacers now? I’m 50/50 on adding a steel bumper later on because I’m leasing the vehicle. What’s your suggestion on adding spacers? And would I add them to just the front? Or both the front and back? And what size spacer?

thank you!

 

[blnewt]

Hey Bl,

I’m going to be doing the spring swap in the next couple of weeks on my 2021 Willys JLU. I read your post and have learned a lot, so thank you!

I think I’ll go the same route as you and install the longer LCAs at the same time to improve the caster.

The one thing I’m still uncertain about is adding spacers. Is this something I need to do? If I plan to add a steel bumper in the future, is it a good idea to add spacers now? I’m 50/50 on adding a steel bumper later on because I’m leasing the vehicle. What’s your suggestion on adding spacers? And would I add them to just the front? Or both the front and back? And what size spacer?

thank you!

I used a 3/4" Rugged Ridge front spacer, it kept the lift pretty even after adding 180 lbs of winch & bumper. If you don't mind a bit of a raked look no need for a spacer if you add a bumper. If you add a winch & a bumper I think a spacer should be added. The spacer I got lists as working on JK Jeeps but they also work fine on JLs, just need to cut the rubber prongs on the stock upper isolators and mark the orientation of the isolators as they have a tilt to them where the spring makes contact.

 

[a23persaud]

I used a 3/4" Rugged Ridge front spacer, it kept the lift pretty even after adding 180 lbs of winch & bumper. If you don't mind a bit of a raked look no need for a spacer if you add a bumper. If you add a winch & a bumper I think a spacer should be added. The spacer I got lists as working on JK Jeeps but they also work fine on JLs, just need to cut the rubber prongs on the stock upper isolators and mark the orientation of the isolators as they have a tilt to them where the spring makes contact.

Okay, thank you! So only spacers in the front are needed, got it.

 

[a23persaud]

I used a 3/4" Rugged Ridge front spacer, it kept the lift pretty even after adding 180 lbs of winch & bumper. If you don't mind a bit of a raked look no need for a spacer if you add a bumper. If you add a winch & a bumper I think a spacer should be added. The spacer I got lists as working on JK Jeeps but they also work fine on JLs, just need to cut the rubber prongs on the stock upper isolators and mark the orientation of the isolators as they have a tilt to them where the spring makes contact.

Hey Bl,

Since you’re so knowledgeable I thought I’d ask: if I just switch out the springs and nothing else (no steel bumper or winch), do you think I’d still have the natural rake that the wranglers come with from the factory? Or would I be sitting more level after the spring swap?

The springs are coming from a 2020 rubicon JLU with 2.0L, hardtop, steel bumper group, and towing package.

-AP

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