Rubicon suspension on a sport worth it ?

[BrandonG]

Hello all , I have a sport with dealer installed rubicon rims and at3s . I have been seeing the rubicon suspension coming up on Kijiji and I am wondering your thoughts on if it’s a good deal . I would be putting 35s on and likely a 1.5 front and 3/4 rear spacer . I’m not looking to do any hardcore wheeling just logging roads etc . The seller from the pic is asking 600 CDN but I may be able to get it for less . Looks to be a complete kit . Thanks for you help

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[BrandonG]

Seller has agreed to $400 for all items pictured if that makes a difference to your thoughts . Thanks

 

[ShadowsPapa]

Only difference is the shocks and springs. All other parts are the same.
You don't need any of the links or control arms or the spring pads, etc. - they are all exactly like what's on your truck now.

IF you have max tow - you'd be losing something going to Rubicon rear springs because the Sport S max tow springs are progressive and handle weight a bit better, but if you don't care about the slight difference, no biggy.
If I was you, I'd use the shocks and simply lift it with the spacers you plan and skip the springs.
I put Rubicon FRONT springs on my Overland because I wanted a less soft and mushy ride and the stiffer springs up front (overland has the softest springs) and I actually put Sport S max tow springs under the back of my OVerland - the Rubicon rear springs are sitting in a box on a shelf.

I guess I should have FIRST asked - what do you want to gain with changing springs? Shocks, yeah, the Fox shocks from a Rubicon would be a notch up - but only for ride and handling. Won't help you off-rode really.

If I had a sport, I'd simply lift it with spacers, level it a bit, and put on Fox shocks.........

 

[BrandonG]

I don’t have max tow , I’m not planning on towing anything of much weight often . Would the springs not also be much better than my sport springs ?

 

[ShadowsPapa]

I don’t have max tow , I’m not planning on towing anything of much weight often . Would the springs not also be much better than my sport springs ?

Better in what way?
Stiffer, yes, a stiffer ride as the Sport is a lighter truck than the Rubicon.
The base Sport without max tow has softer springs like the Overland.
Base Sport and Overland have the softest of the JT springs.

The Rubicon springs shown may give you a slight lift in height (say 3/4" as a guess, a MAX of 1" MAYBE)
Better, can't see how, unless you mean stiffer is better. They will be more stout springs as again, the Rubicon is heavier than the Sport.

Here's the kicker - Rubicon could have any of a number of different springs. So saying "Rubicon springs" could get you anything in a range.

Depending on the truck they came off of. NOT ALL RUBICON JTs will have the same springs.
For example, JUST the rear springs from a Rubicon could be -
Left 450, right 451
Left 449, right 450
Or other possible combinations (those numbers being the last three digits from the spring part numbers)

So what are you looking for - what's "better" to you?

 

[BrandonG]

Ok that makes sense , thank you . I figured they were all the same . I didn’t realize they have different spring rates based on optioned weight within the rubicon range . I figured they would just be a better quality then the sport . Either way for a 3/4 to 1” lift I may as well install them as I have to get in there anyways to add the spacer . That being said should I just get the teraflex spacer kit and add a day star 3/4 “ rear puck or should I get the day star kit with the lower control arms ?

 

[ShadowsPapa]

Ok that makes sense , thank you . I figured they were all the same . I didn’t realize they have different spring rates based on optioned weight within the rubicon range . I figured they would just be a better quality then the sport . Either way for a 3/4 to 1” lift I may as well install them as I have to get in there anyways to add the spacer . That being said should I just get the teraflex spacer kit and add a day star 3/4 “ rear puck or should I get the day star kit with the lower control arms ?

I have mixed feelings on that last part -
if you use Rubicon springs - it's bound to lift the front end a bit. If you put any sort of "leveling kit" in there, too, it's obviously your goal to lift the front a bit more.
So you add the effect of the stiffer springs and the spacer -
If the springs gain you .75" and you use a leveling kit and gain another .75 or even 1.5 if you use certain kits, then you have a total of 1.5" to 2.25" (or so) of lift up front.
OK, bear with me here - the caster on these trucks isn't all that high, really.
And lifting makes it even less. The lower control arms of the MOPAR kit I believe are .25" longer - adding caster. At least one JT owner used those to increase his caster and it improved his handling.
Lifting causes the lower arms to swing in an arc and pull the bottom of the axle back, reducing caster.
Longer arms compensate and push the bottom of the axle tube forward, increasing caster, or adding to positive caster, which is a centering effect on the steering.
Since you are talking leveling at the very least, and even a bit of a lift - I'm leaning toward saying use the lower arms for a small lift.
It will correct caster that's changed by lifting, and if could even increase it a bit over factory stock which won't hurt.
If you were ONLY leveling and not going over about .75" I'd not think much about the lower arms - but you likely will be going over 1.5" - and that appears to be your desire.

 

[BrandonG]

I have mixed feelings on that last part -
if you use Rubicon springs - it's bound to lift the front end a bit. If you put any sort of "leveling kit" in there, too, it's obviously your goal to lift the front a bit more.
So you add the effect of the stiffer springs and the spacer -
If the springs gain you .75" and you use a leveling kit and gain another .75 or even 1.5 if you use certain kits, then you have a total of 1.5" to 2.25" (or so) of lift up front.
OK, bear with me here - the caster on these trucks isn't all that high, really.
And lifting makes it even less. The lower control arms of the MOPAR kit I believe are .25" longer - adding caster. At least one JT owner used those to increase his caster and it improved his handling.
Lifting causes the lower arms to swing in an arc and pull the bottom of the axle back, reducing caster.
Longer arms compensate and push the bottom of the axle tube forward, increasing caster, or adding to positive caster, which is a centering effect on the steering.
Since you are talking leveling at the very least, and even a bit of a lift - I'm leaning toward saying use the lower arms for a small lift.
It will correct caster that's changed by lifting, and if could even increase it a bit over factory stock which won't hurt.
If you were ONLY leveling and not going over about .75" I'd not think much about the lower arms - but you likely will be going over 1.5" - and that appears to be your desire.

That is what I was thinking , mind as well spend a little more for the day star kit with the control arms . I just want to rip everything apart and put it all back together, alignment etc once . I would hate to do it all and then have to do more parts later

 

[ShadowsPapa]

That is what I was thinking , mind as well spend a little more for the day star kit with the control arms . I just want to rip everything apart and put it all back together, alignment etc once . I would hate to do it all and then have to do more parts later

Amen to that! Not that these are difficult, but still - once and done is a lot more fun.
I'll sum it up - IF I was doing what you are doing - springs which will likely have the effect of some lift, spacers which - that's the whole point, and to the point you will be exceeding or meeting 1.5", I'd do the kit.

Now - full disclosure - I put Rubicon front springs under my Overland - after everything has settled in and I measure again. I gained 7/8" in height (Overland has soft springs)
I put max tow springs under the rear- carries the few hundred pounds I haul without dropping as far as the stock Overland springs dropped - and it really dropped before.
I LOST about 3/8" in height in the rear.
I am thinking of gaining that back with spacers - but I don't want to lift the back end higher than the front again, so I'm thinking spacers all around under those springs I put in.
That would mean .875" gain from the front springs, plus .75" for the spacers giving me over 1.5" total lift up front - dang, should I get the kit with the lower arms? I'm thinking about it LOL

 

[BrandonG]

Amen to that! Not that these are difficult, but still - once and done is a lot more fun.
I'll sum it up - IF I was doing what you are doing - springs which will likely have the effect of some lift, spacers which - that's the whole point, and to the point you will be exceeding or meeting 1.5", I'd do the kit.

Now - full disclosure - I put Rubicon front springs under my Overland - after everything has settled in and I measure again. I gained 7/8" in height (Overland has soft springs)
I put max tow springs under the rear- carries the few hundred pounds I haul without dropping as far as the stock Overland springs dropped - and it really dropped before.
I LOST about 3/8" in height in the rear.
I am thinking of gaining that back with spacers - but I don't want to lift the back end higher than the front again, so I'm thinking spacers all around under those springs I put in.
That would mean .875" gain from the front springs, plus .75" for the spacers giving me over 1.5" total lift up front - dang, should I get the kit with the lower arms? I'm thinking about it LOL

The daystar kit with front and back spacers and front lower control arms is available in the low $500 range , I think it’s a good deal given all parts included

 

[BrandonG]

Seller was a great guy and his gladiator was on 39s lol , made mine look like a baby . Crate will be varnished and used as a side table in my bar / pool table area

 

[BrandonG]

Daystar 2” kit ordered . Now to find a lighter 37 tire for my 3.73 gears

 

[j.o.y.ride]

Better in what way?
Stiffer, yes, a stiffer ride as the Sport is a lighter truck than the Rubicon.
The base Sport without max tow has softer springs like the Overland.
Base Sport and Overland have the softest of the JT springs.

The Rubicon springs shown may give you a slight lift in height (say 3/4" as a guess, a MAX of 1" MAYBE)
Better, can't see how, unless you mean stiffer is better. They will be more stout springs as again, the Rubicon is heavier than the Sport.

Here's the kicker - Rubicon could have any of a number of different springs. So saying "Rubicon springs" could get you anything in a range.

Depending on the truck they came off of. NOT ALL RUBICON JTs will have the same springs.
For example, JUST the rear springs from a Rubicon could be -
Left 450, right 451
Left 449, right 450
Or other possible combinations (those numbers being the last three digits from the spring part numbers)

So what are you looking for - what's "better" to you?

Does the weight difference between sport and Rubicon reside in the axles? Wider. Lockers. Wheels. Tires. Or is it sprung weight? The front anti sway is sprung. Anything else of possible substance re: ride quality of springs? I honestly don't know, curious myself.

 

[ShadowsPapa]

Does the weight difference between sport and Rubicon reside in the axles? Wider. Lockers. Wheels. Tires. Or is it sprung weight? The front anti sway is sprung. Anything else of possible substance re: ride quality of springs? I honestly don't know, curious myself.

Leather seats? Are they much heavier??
Sports can be had with power windows, correct? At least the Sport S?
The screen size difference shouldn't add much weight.......
Like you mentioned, the only real thing I can come up with is also the sway bar disconnect motor.
The axles like you said don't count - they are unsprung weight. Wheels as well.
Well, the Rubicon skid plate up front, but that's an option not on all Rubicons, at least I'm pretty sure I crawled under one on the dealer lot that just had the plastic shield. The steel bumper isn't standard, so can explain some of the Rubicon spring differences in the Rubicon line of JTs.

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