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Did a little testing of what JK parts fit TJ suspension wise

264K views 317 replies 130 participants last post by  Autocrat 
#1 ·
I had a set of parts left over from a 3 inch lift on my JK 4 door model. Shocks, springs and sway bars and a few other odds and ends.
I looked all over net trying to find out if any of these will work on a TJ. Seeing as the parts are very new or very low mile, I gave it a shot.
Here is what I found. I tried out all of this on a 2000 TJ so I know for fact it works on that one.
Front JK springs are about 3 inches longer and have higher spring rate (perfect for heavy bumpers or winch on a tj) They fit perfectly on a TJ. So get lift and better weight control.
Front shocks, are about 3 inches longer. Top ends are same no mods. The bottom end on a JK is just a straight bolt thur so You got to press out that bushing in it, and replace with the metal tab from the original shocks on TJ.
It was fairly easy to press out those pieces, I just sprayed with PB Blaster and out they popped. Swapped and installed no issues. Front is very bone simple. 3 inches of FREE lift.
Remember nothing else was addressed in the lift, so on your on with bumpstops and brake lines and other things. I did not mess with any of that, But I am aware and made sure no issues I could see. But jeeps being jeeps can vary year to year.
Rear Here is where things got harder(ish). The rear shocks are 3 inches longer and no mods to shock are needed. Only mod that needs to be done is the lower mounting point needs to be widened a little. remember that front bushing you pressed out. Well wedge it in like you trying to put bolt thru it and mount. Will not fit, take hammer and bash on it a little, that will spread the mount the perfect amount. No farther mods on shocks, they bolted right up.
JK Rear springs are about 3 inches taller so again free lift, plus rated a little higher so it can make up for heavier stuff you done already.
Here is tricky part, the spring has a the same coil at the bottom so it mounts right on the base plate on the axle, its the upper mount that has a coil that is just too small to fit over the bump stop cup. I did not want to cut it cause loose height. So put a little heat to it and using the BS cup as measurement tool I pressed that into the hot coil till it fit. let cool slow. For those that dont know the cup for the bumpstop is bolted on, just remove the rubber snub out and look up in there, its a 5/8 bolt. cup comes right out.
After that I bolted it all back up. 3 free inches of lift. The rear sway bar links are up and touches the E brake cables but nothing to worry about.

Took down road with my new 32s and smooth as silk. Shocks have much larger diameter and I assume better handling..
So for those wanting a cheapish lift or free. Lots of shops have this junk laying around and give it away. See all time on CList guys just about giving it way to get out of shed. Hell even if you got a lift the shocks off JK are smooth about the right lenght.

Dont know if this info is already here, but I looked every where never found anything stating fact. Just a lot of opinions and nay Sayers.
 
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#4 ·
Give or take but yes... But the real winner is how dang smooth it rides. Stock tj with stock 225 size tires wrode like crap. Larger tires and smooth...... Could not believe it. But so glad I took time to do. I had nothing to lose. I was going to order the new N2O kit, but with a box full of left over parts from the Jk I just got the tape measure out and had at it.
 
#8 ·
I explained everything as best I could. This is on a level of 1-10 a 2. In doing. If you can put lift on then this is even easier. Pressing those bushings out is really the hardest. They are stuck in good. So once you spray with BPblaster I put in vice and spun them to break free, they pushed right out after that. Hammer will not work. Press with vice or high lift jack or a Real press. Got to have Torch to make rear coils fit. But heat up red hot and bend. I slowly raised temp to point it would bend. Only heating part I was bending. and slowing heating and let cool sllllllooowww. Just did nto want a broke string later. I have done this on my race cars years ago and they never broke.
 
#9 ·
Pics would still be nice... like before and after at least...

GOOD JOB!!!!


I thinks it's awesome when stuff like this surfaces!!! The only thing is... people will find out that their stock junk aint junk anymore!!! LOL!!!
 
#11 ·
Question: which model of JK Unlimited did your donor hardware come from? Sport, Sahara, Rubicon? The springs are unique to each model, and each has a unique part number sticker on it. If you aren't certain on the model, just posting the part number from one of the front springs will suffice.

I have access to take-off springs and shocks, and I can more or less pick and choose which ones I get. For this reason, I am curious as to which exact ones you used.
 
#26 ·
Front springs have the light blue tag color and number on it is 5212-6317AB
I just took a quick survey from three random Jeeps in my new inventory. Here is what I observed as far as part numbers go.

Sport: 52126317AC
Sahara: 52126316AC
Rubicon: 52126318AC

The last two letters can be ignored; the part number itself is what matters. Based on my current Jeeps, it sounds like your springs came from a Sport rather than a Sahara. Maybe there are other considerations (such as transmission, etc)?

I'll look into it further.
 
#27 ·
I can only say what was on the side of the jeep, it said Sahara with 4 real doors. Maroon colored. I even got the fender flares that were painted, cause guy installed black bushwackers so something. I am not debating what is on what. I had the springs for over 2 years just setting in box.

Was the 3 you pulled them from all 4 doors? I would love to know what the numbers mean, rating wise. Hell the others could be BETTER, I just used what I had. They was shiny and I liked them..................
 
#29 ·
I can only say what was on the side of the jeep, it said Sahara with 4 real doors. ... I had the springs for over 2 years just setting in box.

Was the 3 you pulled them from all 4 doors? I would love to know what the numbers mean, rating wise. Hell the others could be BETTER, I just used what I had. They was shiny and I liked them..................
Please don't get me wrong. I am not doubting what you did or saw. Like you, I am simply reporting what I see on our brand new unsold 2012 Wrangler Unlimiteds.

The fact that your springs have been sitting around for a while got me thinking--what if Mopar changed the spring rate(s) over the years? So, being the curious type that I am, I decided to survey more Jeeps... as in every JK on my lot, new or used, 2dr and 4dr.

Here is my master list of front spring part numbers, followed by a list of the vehicles which wore them.

52126318AC: '12 Rub 4dr HT A5

52126317AC: '12 Spt 4dr HT A5

52126316AC: '12 Sah 4dr HT A5, '12 Sah 4dr HT M6

52126315AB: '08 Sah 4dr HT A4

52126314AC: '12 Rub 2dr HT M6, '12 Spt 2dr HT A5, '10 Spt 2dr ST M6

52126313AC: '12 Sah 2dr HT A5, '11 Spt 2dr ST M6, '08 Rub 2dr HT A4, '09 X 2dr ST M6


The real trick now is to find out exactly how the spring rate varies from part number to part number. Off hand, I would guess the 4dr springs have a higher rate than the 2dr springs (due to the vehicle's greater mass). This suspicion is somewhat confirmed by the fact that no 2dr JK wears springs which were fitted to a 4dr JK.

I have no idea how I would find out the exact rates for any of these springs, nor do I really know where this information might be kept. Nevertheless, I'll give it my best shot next week.
 
#31 ·
Dang Sherpa You alright.
Yeah, well, when I take on a task I am committed. :D

Whats a new 4 door JK weigh?
Chrysler lists the base curb weights for 2012 JKs as follows:

2dr = 3,849 lbs
4dr = 4,231 lbs

Keep in mind that these base weights would be for soft top models with the manual trans and no extra options. This means no A/C on the 2dr.
 
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