JKS JSPEC suspension kit
- Thread starter bobthetj03
- Start date
It definitely looks like more than a 2” lift with the flat fender flares. Going from the bushwhackerstyle to these it definitely gave me more clearance.Sorry glwood
I just skimmed through all 7 pages and a lot of you got more involved researching spring rates that what I did. And maybe I should have!
I'm currently in the middle of installing the 3" JKS JSpec on my 05 Rubicon. So far I have the back finished and working on the front half now. Right now with the rear on the ground its measuring 4.25" of lift rather than 3". I'm a little worried about this as I really wanted this dialed in at 3". Ill have to finish before anything is official. I purchased 33x10.5x15 BFG KM3's and I'm worried I should have just went with 35's if its going to be a 4" lift. If this ends up being a 4" lift in the end Ill be reaching out to JKS to see if I can switch to the 2" springs using all the same parts that came with the 3" kit. Likely the answer is yes.
It is a quality kit. The control arms, track bar, and brackets are all beefy. I added fixed lower control arms, and adjustable upper front control arms. I'm also using the JSpec shocks. I had myself sold on a Rock Krawler X Factor kit, until I was talking to Verne Simons (journalist for Petersons 4wheel mag). He sold me on the idea of using all JKS control arms and track bar with a different brand spring (I can't remember what he said to go with). But now I wish I remembered because I might be swapping springs until I find something I like. But again, too early to say yet since I'm not done. I figured I would just start with all JKS since the kit is so complete.
My TJ still has the factory bumpers so its on the light end. I'll probably never put on those bulky heavy bumpers as I don't like the look. Ill be sticking with stronger classic style bumpers like what Warn or Pro Comp sell.
Ill update when I'm done.
I'm currently in the middle of installing the 3" JKS JSpec on my 05 Rubicon. So far I have the back finished and working on the front half now. Right now with the rear on the ground its measuring 4.25" of lift rather than 3". I'm a little worried about this as I really wanted this dialed in at 3". Ill have to finish before anything is official. I purchased 33x10.5x15 BFG KM3's and I'm worried I should have just went with 35's if its going to be a 4" lift. If this ends up being a 4" lift in the end Ill be reaching out to JKS to see if I can switch to the 2" springs using all the same parts that came with the 3" kit. Likely the answer is yes.
It is a quality kit. The control arms, track bar, and brackets are all beefy. I added fixed lower control arms, and adjustable upper front control arms. I'm also using the JSpec shocks. I had myself sold on a Rock Krawler X Factor kit, until I was talking to Verne Simons (journalist for Petersons 4wheel mag). He sold me on the idea of using all JKS control arms and track bar with a different brand spring (I can't remember what he said to go with). But now I wish I remembered because I might be swapping springs until I find something I like. But again, too early to say yet since I'm not done. I figured I would just start with all JKS since the kit is so complete.
My TJ still has the factory bumpers so its on the light end. I'll probably never put on those bulky heavy bumpers as I don't like the look. Ill be sticking with stronger classic style bumpers like what Warn or Pro Comp sell.
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They do make a 4" spring. But your paper work clearly states you have the 3300 which is the 3" kit. Interesting though that the springs in the kit have different numbers than the individual coils.
https://jksmfg.com/c-1205531-jeep-wrangler-tj-coil-springs.html
https://jksmfg.com/c-1205531-jeep-wrangler-tj-coil-springs.html
Careful taking measurements until both ends are on the ground. Depending on where your jackstands are, the balance point and frame flex will affect them. I had like 3.5" of lift on the rear when I did my 2" OME lift until I got her on all four wheels again. Once I was done, it measured out perfectly at 2"
Fargo - Your right! They do make 4" springs. I only saw 2" and 3" kits for a TJ so I made the wrong assumption. I tried to fix my post before you read it !
Mike_H - Very good point!
I hope to have it sitting on the front by this weekend. I've been chipping away at it little by little each night after the kids are in bed. I've been thinking too that this kit comes with a 1" transfer case drop so maybe it will rotate the rear pinion down a bit too which might help.
!Mike_H - Very good point!
I hope to have it sitting on the front by this weekend. I've been chipping away at it little by little each night after the kids are in bed. I've been thinking too that this kit comes with a 1" transfer case drop so maybe it will rotate the rear pinion down a bit too which might help.
OP
Yeah I'd wait till you have the front done and 500+ miles clocked in before you get a final lift measurement.
Did you happen to measure the springs before you installed them? I'd be interested in knowing the length of them. If the 3" are anything like the 2" the spring rates are higher than stock to help compensate for jeeps with aftermarket steel bumpers, tire carriers, later spare tire, winch, armor etc. If your Jeep is stock it will likely sit higher than the advertised lift height due to the lack of weight to help compress the initial coils to their designed sag (ride level) point.
JKS told me their 2" springs have the following specs
JKS 2" Front - 150/220 lbf/in - 19"
JKS 2" Rear - 190/240 lbf/in - 14"
What would be interesting to know know is if the length of the 3" springs are 1" more than the 2" 20"/15" or if they are not then they likely just increased the spring rate to help hold the jeep higher up. I do really wish someone would make a true progressive 2" spring.
Look forward to seeing your jeep on all 4. Do like that color.
JKS told me their 2" springs have the following specs
JKS 2" Front - 150/220 lbf/in - 19"
JKS 2" Rear - 190/240 lbf/in - 14"
What would be interesting to know know is if the length of the 3" springs are 1" more than the 2" 20"/15" or if they are not then they likely just increased the spring rate to help hold the jeep higher up. I do really wish someone would make a true progressive 2" spring.
Look forward to seeing your jeep on all 4. Do like that color.
These are the 3” numbers
Uncompressed Length Front: 20
Spring Rate Front: 150/200
Uncompressed Length Rear: 15.125
Spring Rate Rear: 190/240
I just measured the front. They are 20" long. I cant measure the rear now. But JMT got you covered.
I didnt have a chance to work on it more last night, but hopefully I get a little time tonight to toss in front springs, shocks, and control arms!
I'm gonna be doing a lift soon with 3" jks springs. It's not going to be the complete kit, just jks springs and trackbars with bilstein shocks and currie uppers.
I wanted the currie kit, but figured I'd save a few hundred just using currie control arms.
Jks components seem to be top notch quality, though not as well designed as currie. Curries control arms are clearly worth the extra cost over jks control arms.
I planned on starting my own thread, but maybe I just hijack this one, lol.
I wanted the currie kit, but figured I'd save a few hundred just using currie control arms.
Jks components seem to be top notch quality, though not as well designed as currie. Curries control arms are clearly worth the extra cost over jks control arms.
I planned on starting my own thread, but maybe I just hijack this one, lol.
Quick update. I got the front springs and control arms in and the rear has already dropped to 1/4" above 3". Still have to do the transfer case drop. My concern is all gone.Ill post pics after I get the new wheels on and get the last few things dialed in!
Bushings with rolled steel center sleeves are slightly elongated and tend to move on the bolt . Same issue with rough country track bar bushings.
Been noticing some clunking coming from the rear lately over certain road undulations...think it could be my RC track bar for the reason listed above?
If so, can the bushings be replaced?
If the bolt sleeve is moving on the bolt, then the bolts are not tight. Elongation of the sleeve has nothing to do with the movement.
Well I had it going on with mine and the rough country track bar accepted the stock replacement bushing...the rough country bushings were made in Mexico and the rubber was extremely soft.
My Lift has only been on the vehicle about 13,000 miles
In regard to the the bolt being tight, it seems a good relationship between the bolt and the sleeve would be desirable... but I do follow the thought process.