Replace Upper or Lower Control Arms on 2.5 Lift ?

Replace Which Front Arms?

  • Front Upper

    Votes: 0 0.0%
  • Front Lower

    Votes: 17 81.0%
  • Both

    Votes: 3 14.3%
  • Neither

    Votes: 1 4.8%

  • Total voters
    21
  • Poll closed .

JKbrick

Active Member
No you didn't. Here was my exchange with TJ.





TJ quoted my post asking about REAR lowers and responded by talking about fixed arms for caster.

And even in the post about the pinion angle, I fail to see how putting longer rear lowers on fixes the pinion angle. Shouldn't it make it worse because the yoke will be turned further toward the ground? Now, with longer rear uppers you can straighten out the driveline angle because the yoke is twisted up and more in line with the transfer case output. I dunno, maybe I'm just all fucked up but longer REAR lowers make no sense to me without also having longer REAR uppers.

I agree plus if you lengthen both sets of rear arms your track bar would get into your coil, heck mine did just with rear uppers to adjust for a driveshaft. It is probably more severe on my 2 door than for most of you guys. I am too OCD to replace fixed length arms with fixed length arms, something would bother me if it wasn't set just right but I'm goofy that way


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Mountainjk10

Caught the Bug
No you didn't. Here was my exchange with TJ.





TJ quoted my post asking about REAR lowers and responded by talking about fixed arms for caster.

And even in the post about the pinion angle, I fail to see how putting longer rear lowers on fixes the pinion angle. Shouldn't it make it worse because the yoke will be turned further toward the ground? Now, with longer rear uppers you can straighten out the driveline angle because the yoke is twisted up and more in line with the transfer case output. I dunno, maybe I'm just all fucked up but longer REAR lowers make no sense to me without also having longer REAR uppers.

The JKS fixed rear lower control arms are the same length as stock but much beefier.


Sent from my iPhone using WAYALIFE mobile appedit: here's the description from Quadratec.
J Link control arms provide peace of mind, upgrading the weak factory lower control arms to a massive, practically indestructible piece of gear built from 2” x .250 wall DOM tubing. J Link control arms feature Cleveite brand rubber bushings to absorb noise and reduce vibrations for a quiet and comfortable ride. J Link arms are the same length as the stock control arms and will fit with up to 4.5" of lift.
 
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So the J Link arms are slightly longer than stock. I want to say 3/8" in the front and 1/2" in the rear which will get you just shy of 5* caster on a 3.5" lift. In the rear it pushes the axle back just slightly back into stock position and even though there aren't really vibration issues on a JK with these milder lifts, it puts the pinion angle back in line with the transfer case output which is technically correct for the factory driveshaft.
 

wayoflife

Administrator
Staff member
The JKS fixed rear lower control arms are the same length as stock but much beefier.

edit: here's the description from Quadratec.
J Link control arms provide peace of mind, upgrading the weak factory lower control arms to a massive, practically indestructible piece of gear built from 2” x .250 wall DOM tubing. J Link control arms feature Cleveite brand rubber bushings to absorb noise and reduce vibrations for a quiet and comfortable ride. J Link arms are the same length as the stock control arms and will fit with up to 4.5" of lift.

Wow, a fixed length control arm that's the same as factory and is a perfect fit up to 4.5" of lift. Sounds like sliced bread has some competition! :thumb:

So the J Link arms are slightly longer than stock. I want to say 3/8" in the front and 1/2" in the rear which will get you just shy of 5* caster on a 3.5" lift. In the rear it pushes the axle back just slightly back into stock position and even though there aren't really vibration issues on a JK with these milder lifts, it puts the pinion angle back in line with the transfer case output which is technically correct for the factory driveshaft.

The factory rear drive shaft has rzeppa joints on both ends. In other words, it technically doesn't matter what angle they're sitting at in terms of vibrations and it's a good thing being that if the rear JKS control arms really are 1/2" longer than stock, that's A LOT of adjustment for a just 0"-2.5" lift. Of course, I suppose now wouldn't be the time to talk about how steep the rear drive shaft sits on a 2-door with just 3" of lift or how it puts the CV boots on both the output and pinion shaft in a constant state of pinch and causing them to fail prematurely. Certainly, it's nothing I've ever seen happen before and far from being something the "average Jeeper" needs to concern themselves with.
 

cozdude

Guy with a Red 2-Door
Wow, a fixed length control arm that's the same as factory and is a perfect fit up to 4.5" of lift. Sounds like sliced bread has some competition! :thumb:



The factory rear drive shaft has rzeppa joints on both ends. In other words, it technically doesn't matter what angle they're sitting at in terms of vibrations and it's a good thing being that if the rear JKS control arms really are 1/2" longer than stock, that's A LOT of adjustment for a just 0"-2.5" lift. Of course, I suppose now wouldn't be the time to talk about how steep the rear drive shaft sits on a 2-door with just 3" of lift or how it puts the CV boots on both the output and pinion shaft in a constant state of pinch and causing them to fail prematurely. Certainly, it's nothing I've ever seen happen before and far from being something the "average Jeeper" needs to concern themselves with.

It's super steep that's for sure! I know after I installed my coilovers I was sitting at about 5" of lift even tho I had them dialed low. I was scared to drive home from Ohio with how steep it was. Installed the new shaft two days later
 

wayoflife

Administrator
Staff member
It's super steep that's for sure! I know after I installed my coilovers I was sitting at about 5" of lift even tho I had them dialed low. I was scared to drive home from Ohio with how steep it was. Installed the new shaft two days later

Well duh! Don't you know you could have just installed a set of fixed length JKS J Link lower control arms that are 1/2" longer than stock to fix that? Oh wait, you're running fancy suspension stuff that had you sitting .5" taller than what they're good for. Clearly, you're no average Jeeper so it wouldn't apply. :crazyeyes:
 

cozdude

Guy with a Red 2-Door
Well duh! Don't you know you could have just installed a set of fixed length JKS J Link lower control arms that are 1/2" longer than stock to fix that? Oh wait, you're running fancy suspension stuff that had you sitting .5" taller than what they're good for. Clearly, you're no average Jeeper so it wouldn't apply. :crazyeyes:

Well shit! Let me sell my synergy rear upper arms, put stock ones back on, and put some jks lowers on. I hope my Adams shaft will work with that
 

wayoflife

Administrator
Staff member
Well shit! Let me sell my synergy rear upper arms, put stock ones back on, and put some jks lowers on. I hope my Adams shaft will work with that

Clearly, you've been spending way too much time on this forum and bought into a tangle of misconceptions. :naw:
 

wayoflife

Administrator
Staff member
BTW, before all the JKS fanboys chime in with the typical nonsense about how they don't give me free shit, allow me to say that I REALLY LIKE JKS. They make fine products and I have bought and run many of their products on my Jeeps. In fact, what I was running on Nemo before selling him was a set of JKS J-Axis ADJUSTABLE control arms and they were awesome. A little pricy for sure but they worked exceptionally well, rotated in the arm to help prevent binding and even came with bonded rubber bushings on both ends. :yup:

DSC00093.jpg

I know I know, it's a fancy "contraption of a control arm" but it's one that I would highly recommend and it's made by JKS :thumb:
 

GraniteCrystal

New member
Reading through all this for the 3rd time and still trying to make sense of it.

Eddie, you're basically just saying that the control arms need not be replaced and stock ones are fine?

I just bought the 3.5" JKS lift that comes with their lower control arms, front and rear and trying to understand all this. Not just for buying the right parts but for really understanding how all this works together.

°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°
http://wayalife.com/showthread.php?p=621404
 

WJCO

Meme King
Installed a 2.5" Teraflex coil w/ shock lift back in January. Was told to also do front lower arms to correct geometry/caster, but was waiting to do that when I got new wheels/tires. Delayed my wheels and tires until now. But now I was recommended to actually replace the front upper arms instead?

Which is better to replace? front upper or lower? Will be on a 2.5" lift with 35's

OP, Front lower arms is all you need for now. Follow the alignment thread and get your caster to 4.2. And keep an eye on your front driveshaft :thumb:
 

WJCO

Meme King
Reading through all this for the 3rd time and still trying to make sense of it.

Eddie, you're basically just saying that the control arms need not be replaced and stock ones are fine?

I just bought the 3.5" JKS lift that comes with their lower control arms, front and rear and trying to understand all this. Not just for buying the right parts but for really understanding how all this works together.

°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°
http://wayalife.com/showthread.php?p=621404

Front lower arms will help get your caster and pinion angle back in spec. Rear lower will help put your rear axle centered in your wheel well. Did it come with rear uppers?

EDIT: I'm saying put them on because they came with the kit. I ran stock lowers on mine with a 4 inch lift for years. I just replaced them last week because the factory bushings were worn out. I went adjustable for the Johnny Joints, but left them at stock length.
 
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wayoflife

Administrator
Staff member
Eddie, you're basically just saying that the control arms need not be replaced and stock ones are fine?

I just bought the 3.5" JKS lift that comes with their lower control arms, front and rear and trying to understand all this. Not just for buying the right parts but for really understanding how all this works together.

With 3.5" of lift, installing a set of adjustable front lower control arm is desirable to set your caster to a factory 4°. If in fact the fixed length front lower control arms you installed were 3/8" longer, they should have taken care of this or there about, assuming your coils yielded 3.5" of lift and not more like so many lifts do. This is not to say they are "needed", just something most people appreciate as it provides better handling. Rear lowers are NOT necessary especially for the "average Jeeper". If you have a 2-door, your rear drive shaft will be sitting at a steep enough angle that the CV boots will sit in a constant state of pinch. Sooner than later, this WILL cause the boots to fail. The solution is to install a new rear u-joint style shaft but in order to install it, you NEED adjustable rear upper control arms to set your pinion angle. Again, JKS makes great adjustable control arms called the J-Axis and I'm quite sure Trail Jeeps will sell them to you. :yup:
 
BTW, before all the JKS fanboys chime in with the typical nonsense about how they don't give me free shit, allow me to say that I REALLY LIKE JKS. They make fine products and I have bought and run many of their products on my Jeeps. In fact, what I was running on Nemo before selling him was a set of JKS J-Axis ADJUSTABLE control arms and they were awesome. A little pricy for sure but they worked exceptionally well, rotated in the arm to help prevent binding and even came with bonded rubber bushings on both ends. :yup:

attachment.php


I know I know, it's a fancy "contraption of a control arm" but it's one that I would highly recommend and it's made by JKS :thumb:

I guess as a follow up to this, across the board we have simply had really good luck with the JKS stuff, it has solved a lot of problems we ran into with some of the other brands. That's been our experience, so that's what we promote. They haven't steered us wrong yet!
 

WJCO

Meme King
I guess as a follow up to this, across the board we have simply had really good luck with the JKS stuff, it has solved a lot of problems we ran into with some of the other brands. That's been our experience, so that's what we promote. They haven't steered us wrong yet!

I for one believe you and have had good experiences with JKS myself and have heard good feedback from others. However this thread is a perfect example of a ton of confusion for many, regardless of the quality of the product. We really strive to make sure information here is accurate and don't want members to spend money that they don't need to spend. The OP would be fine without the rear arms.
 
I agree with you actually he would! I think we all got a little caught up in the "I need to prove a point, Dammit!" Mode
 

piginajeep

The Original Smartass
Where's JKS being made now? Since they closed down the original shop since it was bought out?

If it's anything like Zone or BDS quality I would rather run teraflex.


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