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-   -   Jk springs on a tj (http://www.wranglerforum.com/f282/jk-springs-on-a-tj-243722.html)

bowerslj 05-19-2013 07:07 PM

Jk springs on a tj
 
Hello Everyone!

My boss recently installed an AEV lift on his Jeep and has all of his stock JK suspension parts available for cheap. Does anyone know if it's possible to use 2012 JK springs on a 2003 TJ? I'm asking because if it is in fact possible, it would e a nice alternative to a budget boost. Anyone that can share their knowledge on the subject would definitely be helping me out. Thanks!

wwch99tj 05-19-2013 07:14 PM

http://www.wranglerforum.com/f5/did-...se-150213.html

bowerslj 05-19-2013 08:51 PM

Awesome write up! Thanks for sharing. I think I might just go with aftermarket shocks, but he has the JK shocks laying around that he took off, too. The shocks are in good shape and would save me a bunch of cash, but it might be best to just buy new ones. Thoughts?

bowerslj 05-19-2013 09:18 PM

After reading a little bit further, it seems that there are mixed reviews about the compatibility of JK springs on TJ models.

TJspeed 05-20-2013 01:03 AM

Quote:

Originally Posted by bowerslj (Post 3772715)
After reading a little bit further, it seems that there are mixed reviews about the compatibility of JK springs on TJ models.

Look here --> https://www.google.com/search?q=jk+s...hrome&ie=UTF-8

00tj2 05-20-2013 06:44 AM

I'm in the process of doing it now. I had stock front springs with 2" BB. I lot lift when I added just the front JK springs and shocks but I must say that the front end is much smoother now. I will replace the rear once I get a new gas tank skid. Once that is done I will do a small write up. Need to drop the tank to use some heat so I don't snap the upper rear shock bolts.

97flexy 05-21-2013 12:25 AM

Quote:

Originally Posted by 00tj2 (Post 3773711)
I'm in the process of doing it now. I had stock front springs with 2" BB. I lot lift when I added just the front JK springs and shocks but I must say that the front end is much smoother now. I will replace the rear once I get a new gas tank skid. Once that is done I will do a small write up. Need to drop the tank to use some heat so I don't snap the upper rear shock bolts.

you have a picture of your jeep on JK springs next to a stock TJ?

00tj2 05-21-2013 09:37 AM

I do not but I will try to get a pick of the way it looks now.

TheBestCoast 05-21-2013 11:57 AM

pretty much if its a 4 door jk with higher rated suspension (the last 2 numbers on the part number for front and back springs) you may get a max of around 2" all around. IF you have a 2.5 liter... if youve got a 4.0 forget it and go with v8 XJ front springs, and move your front springs to the rear. much better budget lift

bowerslj 05-21-2013 07:14 PM

That's interesting. I wasn't aware that I could move the front springs on my TJ to the rear. The XJ is the older style Cherokee, right?

bowerslj 05-21-2013 07:17 PM

Quote:

Originally Posted by TheBestCoast (Post 3778279)
pretty much if its a 4 door jk with higher rated suspension (the last 2 numbers on the part number for front and back springs) you may get a max of around 2" all around. IF you have a 2.5 liter... if youve got a 4.0 forget it and go with v8 XJ front springs, and move your front springs to the rear. much better budget lift

Oh yeah, if I went with this configuration, what length of shocks would I need to purchase? Maybe an additional 3" of travel? Would I also need to upgrade my bump stops? I really am a novice with this stuff, so your input is greatly appreciated!

00tj2 05-21-2013 08:03 PM

Sorry to say but if you put your front springs on the rear your going to be looking at about 4-6" of lift and wrong spring rate. It won't work, the spring rates are way too off along with the length. But yes, the XJ or ZJ front springs would of been a better choice for me. That being said I am looking forward to installing the rears to see how much better the ride will be. That's if I don't by the TJ unlimited I just found for 14k with 66k miles. Hummmm decisions decisions.....

00tj2 05-21-2013 08:04 PM

Oh and btw, the springs I have are from a 2012 unlimited rubicon.

bowerslj 05-21-2013 10:02 PM

Quote:

Originally Posted by 00tj2 (Post 3779688)
Oh and btw, the springs I have are from a 2012 unlimited rubicon.

Did you have to modify the rear JK springs to get them to fit on your TJ? The initial response to my question included a link which indicated that the JK springs needed to be heated and bent to fit into the TJ's rear bump stop bracket. Was that the case with your install? I'm not looking for a big lift - 2" would be perfect. If that's what I can get from using JK springs, then count me in!

Qurtyslyn 05-22-2013 07:55 PM

Quote:

Originally Posted by bowerslj (Post 3780194)
Did you have to modify the rear JK springs to get them to fit on your TJ? The initial response to my question included a link which indicated that the JK springs needed to be heated and bent to fit into the TJ's rear bump stop bracket. Was that the case with your install? I'm not looking for a big lift - 2" would be perfect. If that's what I can get from using JK springs, then count me in!

I haven't done the rear's on mine yet. I'm using the shocks and springs off a JK.

Front's went on without issue, just had to change the bottom mount on the JK shock.

Rears are going to be a close fit, going to see this weekend.

00tj2 05-22-2013 08:08 PM

I haven't done my rears yet either but from my understanding I will have to heat and open up the last coil the seats onto the top bucket. Right now I'm looking at a 2004 LJ auto w 66k for around 12k.. So my TJ is on hold till I decided.

ebilek231 05-22-2013 08:35 PM

yes you can i did it to mine with a little modifications :)

bowerslj 05-23-2013 09:43 AM

Quote:

Originally Posted by Qurtyslyn (Post 3783426)

I haven't done the rear's on mine yet. I'm using the shocks and springs off a JK.

Front's went on without issue, just had to change the bottom mount on the JK shock.

Rears are going to be a close fit, going to see this weekend.

Keep me posted on your progress with the rear shocks. I can score all four shock and springs from my buddy for around $100. Any pics you can post would be awesome, too!

Qurtyslyn 05-24-2013 04:28 PM

I will try and get some pictures on Saturday, if I can find time around dump runs. I've always been horrible about getting pictures.

I got my shocks and springs for 25$, so if I have to do a little extra work I'm fine with that. I'd rather not heat the springs though if I don't have to. I'd have to find someone with a Torch.

bowerslj 05-25-2013 11:45 PM

Quote:

Originally Posted by Qurtyslyn (Post 3789945)
I will try and get some pictures on Saturday, if I can find time around dump runs. I've always been horrible about getting pictures.

I got my shocks and springs for 25$, so if I have to do a little extra work I'm fine with that. I'd rather not heat the springs though if I don't have to. I'd have to find someone with a Torch.

Thanks. It would be helpful to see some pics of the JK shocks lift.

Kevin063 05-26-2013 07:25 AM

I did this in Feb. No complaints, I got right around 2.5" after everything settled. The ride is fantastically smooth. Zero regrets here.

Pink_Percy 05-26-2013 08:53 AM

1 Attachment(s)
Quote:

Originally Posted by kevin063 (Post 3793752)
i did this in feb. No complaints, i got right around 2.5" after everything settled. The ride is fantastically smooth. Zero regrets here.



Attachment 253661

bowerslj 05-27-2013 10:48 AM

Quote:

Originally Posted by Pink_Percy (Post 3793871)

Agreed. I've determined it's possible from all of the previous posts, but it would be nice to see some before and after pics. Lastly, does anyone know of the exact modifications that need to be made to the rear JK springs? I've head that either cutting or heating is necessary to get them to fit.

Qurtyslyn 05-27-2013 05:00 PM

Quote:

Originally Posted by bowerslj (Post 3796973)
Agreed. I've determined it's possible from all of the previous posts, but it would be nice to see some before and after pics. Lastly, does anyone know of the exact modifications that need to be made to the rear JK springs? I've head that either cutting or heating is necessary to get them to fit.

Had the rear end apart today and checked it out, no pictures however as I was working on my own.

The rear springs need to be heated and opened up to 70mm to fit on the top, my new springs are just over 50mm (50mm on one, 52mm on the other.) This will fit it in the seat, and around the bump stop cup (or you could change the bump stops and remove that issue) which is 60mm (or 65mm, can't remember now).

The bottom is larger than the seat, so it will fit, however it may move. Adding a spring retainer may be necessary, but I wont know until I've got the top fitted.

Everything else is straight forward. You have to detach the rear sway bar and shocks (I'm replacing mine so no issues) and the axle breather hose on the drivers side has to be loosened so you can drop the axle far enough (it catches on some electrical and metal lines above the coil).

To fit JK shocks on the rear, you have to shorten the metal bushing on the bottom of the shock by 5mm (should measure 35mm when you're done). The top mount is the same. I did it with a grinder, the hack saw didn't cut it.

bowerslj 05-27-2013 08:57 PM

Quote:

Originally Posted by Qurtyslyn (Post 3797762)

Had the rear end apart today and checked it out, no pictures however as I was working on my own.

The rear springs need to be heated and opened up to 70mm to fit on the top, my new springs are just over 50mm (50mm on one, 52mm on the other.) This will fit it in the seat, and around the bump stop cup (or you could change the bump stops and remove that issue) which is 60mm (or 65mm, can't remember now).

The bottom is larger than the seat, so it will fit, however it may move. Adding a spring retainer may be necessary, but I wont know until I've got the top fitted.

Everything else is straight forward. You have to detach the rear sway bar and shocks (I'm replacing mine so no issues) and the axle breather hose on the drivers side has to be loosened so you can drop the axle far enough (it catches on some electrical and metal lines above the coil).

To fit JK shocks on the rear, you have to shorten the metal bushing on the bottom of the shock by 5mm (should measure 35mm when you're done). The top mount is the same. I did it with a grinder, the hack saw didn't cut it.

What did you use to heat the springs? Is this something that can be done in in my garage? I don't have any high-end heating implements.

Qurtyslyn 05-28-2013 11:34 AM

Haven't heated them yet. Going to need more than a propane torch, which is all I have at home. I've got to wait on my uncle getting back from his trip, then I'll have to take a ride over to his house to get it done.

A spring shop would also be able to do it, and it shouldn't be too expensive.

bowerslj 05-29-2013 09:58 PM

Good idea. Probably somewhere like Midas or another brake and muffler shop should be able to do it...maybe?

Qurtyslyn 05-30-2013 11:28 AM

A lot of shops around here wont do it because of liability, wouldn't hurt to ask though. I know the dealerships I work for wont do it for a customer, they may do it for me though.

Because of your name and location, any relation to Ty or Roger Bowers?

bowerslj 05-30-2013 11:29 PM

Nope...not related. I'm originally from Indiana.

Berend 05-31-2013 02:31 AM

Ok I'm feeling like no one is really sure about this. Regardless of if it works or not, I'm picking up the springs and shocks tomorrow for $15. The chance of getting a 2-3 inch lift for $15 is worth wasting $15 if it doesn't work. I could always sell them and make more off them anyways.

The suspension is off of an 08 JK and I have an 01 TJ Sahara. Stock suspension with 2" body lift, which I will be taking off if this works.

So here's what it seems like. On the front, the springs fit right in like the stock TJ ones do. The shocks need a little modification, but nothing extreme or really that challenging.

For the rear, the shocks will go on fine with a little widening of the bottom mounting hole. I just need to take the bracket from the front shocks and hammer it in a little bit. For the springs, the bottom fits on just fine, but the top needs modification. Just a little heat to widen it to fit around the bump stops.

So, if this is true, it shouldn't be too challenging. One question: what do I use to heat the spring? Also, does anyone know if this will cause me to need anything else replaced, such as my drive shaft or anything of that nature? I figure since I already have 2" of lift, this will only lift it about .5-1" more.


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