Help with my control arms

Shaydon15

Shaydon15

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Aug 1, 2021
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36
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Colorado
Okay! After a long day! I’m beat up. My Jeep won 😂 to make a long story semi short. I put a 4 inch rough country lift kit on my 2000 Jeep tj. From there on, my Jeep sucked. So! I dumped tons of money into it. And now we’re here. I have curry steering , jks front track bar, jks quicker disconnects, and…. I think that’ll do for the front. Right now I am strruggggling. Because my control arms arnt adjusted to the right length at all, casters out of wack, my track bar isn’t set right so when I tried to bring it to full bump, it was getting caught on my track bar end. And then once I got it kinda fixed, I can’t get my bump stops centered because the rough country lift control arms won’t allow me to go small enough, so the bump stops kinda hit the back. And I don’t know if that’s an issue. And I don’t know what order to go in, should I set my track bar, then try to set my control arms? Well as of right this second, my coils, shocks, sway bar end links, and tires are all off the Jeep and I don’t know what to do. Any helpppp, I may just be beat up by my Jeep and am not sure what to do anymore 😂
 
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The track bars and axle centers really don’t have any bearing on the control arm set up and pinion angle as they work 90 degrees to each other - just take it one thing at a time-

if it were me I would center the axles and cycle everything to check clearance (you may need a rear track bar relocation bracket ) and make sure you aren’t over extending your shocks, get the bump stops close and get a caster bolt kit at a parts store and get the caster as close as I could, set the toe then see where you are.

I have some rough country control arms, and JKS parts and upgraded steering, Rancho shocks and overall it drives phenomenal- but it took quite a bit of tuning-I have 38,000 miles on the lift so we will so how it does over time.

If people (me included) would not try to beat the system and just buy really good control arms to start with, the rest is easy. Not shaming you- just be patient, be conscious of what you are doing, and remember bolts turn both ways so you can always change things later.

At this point you may want to start shopping control arms- I converted part of my RC ends to Johnny Joints and have been really pleased, and I’m questioning why yours have your bump stops out of kilter. Typically the RC arm is not the problem, it is the bushings that fail fast.

As a caveat, I’m not the last word in suspension tuning at all on here, I’m just telling you what I would do if we were hanging out at my little shop trying to work with what you had- we have some guys on here who have forgotten more than I know, so if you see some posts that show a better path, take heed.
 
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John Cooper said:
Oh lord a RC thread.... man and we thought the JJ vs MC was bad!!!!!!

@AndyG we are gonna need you to monitor this one please!!!!!! :ROFLMAO: :ROFLMAO::ROFLMAO:
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AndyG said:
The track bars and axle centers really don’t have any bearing on the control arm set up and pinion angle as they work 90 degrees to each other - just take it one thing at a time-

if it were me I would center the axles and cycle everything to check clearance (you may need a rear track bar relocation bracket ) and make sure you aren’t over extending your shocks, get the bump stops close and get a caster bolt kit at a parts store and get the caster as close as I could, set the toe then see where you are.

I have some rough country control arms, and JKS parts and upgraded steering, Rancho shocks and overall it drives phenomenal- but it took quite a bit of tuning-I have 38,000 miles on the lift so we will so how it does over time.

If people (me included) would not try to beat the system and just buy really good control arms to start with, the rest is easy. Not shaming you- just be patient, be conscious of what you are doing, and remember bolts turn both ways so you can always change things later.

At this point you may want to start shopping control arms- I converted part of my RC ends to Johnny Joints and have been really pleased, and I’m questioning why yours have your bump stops out of kilter. Typically the RC arm is not the problem, it is the bushings that fail fast.

As a caveat, I’m not the last word in suspension tuning at all on here, I’m just telling you what I would do if we were hanging out at my little shop trying to work with what you had- we have some guys on here who have forgotten more than I know, so if you see some posts that show a better path, take heed.
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Thanks for responding!
The last thing I did was get my springs back in and tires on, and was able to measure inside the wheel well to some tread on the tire and I think I got it centered. I’m going to take it on again tomorrow, and this helped me figure out how I want to go about this. I do have an adjustable jks track bar and relocation bracket coming in the mail for the rear. I’m mainly just starting on the front. Ahhh, I’d be so happy if I knew some jeepers with a little shop that I could trade my welding and handyman skills for some Jeep knowledge. How do you make sure you’re not over extending the shocks? Also, how do I figure out what bump stops I need? I tried googling so much about it and I just can’t figure it out. I am confused about the bump stop centering portion, I took out my springs and tried to line up them but I couldn’t spin in the lower control arm any more to center it up. It’s sitting on the rear end of the contact… don’t I need to get that perfect (adjusting the lowers should do that right?) and then after that I just need to set caster and so on and so forth? Is the centering of the bump stop to the contact all you use for making the length of the lowers? I shouldn’t worry about the length of them so much right? Just make sure they’re centered in the contact? I also don’t know how I’m supposed to do that because they wouldn’t center up 😂 ahhhh.
 
Shaydon15 said:
Thanks for responding!
The last thing I did was get my springs back in and tires on, and was able to measure inside the wheel well to some tread on the tire and I think I got it centered. I’m going to take it on again tomorrow, and this helped me figure out how I want to go about this. I do have an adjustable jks track bar and relocation bracket coming in the mail for the rear. I’m mainly just starting on the front. Ahhh, I’d be so happy if I knew some jeepers with a little shop that I could trade my welding and handyman skills for some Jeep knowledge. How do you make sure you’re not over extending the shocks? Also, how do I figure out what bump stops I need? I tried googling so much about it and I just can’t figure it out. I am confused about the bump stop centering portion, I took out my springs and tried to line up them but I couldn’t spin in the lower control arm any more to center it up. It’s sitting on the rear end of the contact… don’t I need to get that perfect (adjusting the lowers should do that right?) and then after that I just need to set caster and so on and so forth? Is the centering of the bump stop to the contact all you use for making the length of the lowers? I shouldn’t worry about the length of them so much right? Just make sure they’re centered in the contact? I also don’t know how I’m supposed to do that because they wouldn’t center up 😂 ahhhh.
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Perfect bump stop center is not at all as critical as overextending or crushing shocks, caster, toe, pinion angle,etc. They just need to work.

if the shock has 8” of travel for instance, you want like 3/4” of down travel left when it hits the bump stop and you want about 1” of up travel left when the tire drops so you don’t tear the shock off. Use the search engine, this is where cycling everything reveals the mechanical limits and tells you what you need to do...and you have it down far enough it is fairly easy, just work safe.
 
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@JMT beat me to it, but you basically have to start from square 1. Get the thing up on jack stands again (at the frame). Get a jack under the front axle. Pull the tires, springs, disconnect the track bar , sway bar, shocks (from the bottom). Pull any bump stop extension you have, pull the jounce bumpers out too. Now, use the jack and move the axle to the "hard stop". It should be the jounce bumper cup and the pad on the axle touching since everything else is disconnected. Now, adjust your control arms (uppers and lowers) to get the bump stop centered up as much as possible and eyeball the pinion angle (you want it to be aproximately pointed at the T-case). You should be able to get it nearly perfect. Don't worry about length or making them "the same." Once you have the axle positioned, check that its square to the frame. If it is, great. If its not, it should take only a minor adjustment.

Now, you get to re-install all the stuff you disconnected, except the springs and tires. You will cycle the axle and make sure the track bar and steering clear your differential. You watch your shocks and when they come close to bottoming out, you need to measure the distance between the jounce bumper cup and the pad. That distance is your bumpstop extension. When you cycle the axle, you need to do full bump (lift the axle horizontally up) and check articulation (each side up when the other side is down). You're making sure the axle can move to its full extents of motion without damaging anything. Finally, once you're convinced you have all the hard parts clearing, throw a tire on and check its clearance to the fenders and flares. Remember to turn it to full lock both directions.

Once you have that done, you'll need to put the springs back in (which generally means disconnecting a couple things again) and then getting the jeep back on its own weight. Now, you'll set pinion angle. Pinion angle takes precedence over caster. At 4" of lift, you should be OK on caster angle. They will be a little vague on center, but it's not really correctable unless you install locking hubs.

Good Luck. Its a fair amount of work but its all doable in less than a day.
 
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Mike_H said:
@JMT beat me to it, but you basically have to start from square 1. Get the thing up on jack stands again (at the frame). Get a jack under the front axle. Pull the tires, springs, disconnect the track bar , sway bar, shocks (from the bottom). Pull any bump stop extension you have, pull the jounce bumpers out too. Now, use the jack and move the axle to the "hard stop". It should be the jounce bumper cup and the pad on the axle touching since everything else is disconnected. Now, adjust your control arms (uppers and lowers) to get the bump stop centered up as much as possible and eyeball the pinion angle (you want it to be aproximately pointed at the T-case). You should be able to get it nearly perfect. Don't worry about length or making them "the same." Once you have the axle positioned, check that its square to the frame. If it is, great. If its not, it should take only a minor adjustment.

Now, you get to re-install all the stuff you disconnected, except the springs and tires. You will cycle the axle and make sure the track bar and steering clear your differential. You watch your shocks and when they come close to bottoming out, you need to measure the distance between the jounce bumper cup and the pad. That distance is your bumpstop extension. When you cycle the axle, you need to do full bump (lift the axle horizontally up) and check articulation (each side up when the other side is down). You're making sure the axle can move to its full extents of motion without damaging anything. Finally, once you're convinced you have all the hard parts clearing, throw a tire on and check its clearance to the fenders and flares. Remember to turn it to full lock both directions.

Once you have that done, you'll need to put the springs back in (which generally means disconnecting a couple things again) and then getting the jeep back on its own weight. Now, you'll set pinion angle. Pinion angle takes precedence over caster. At 4" of lift, you should be OK on caster angle. They will be a little vague on center, but it's not really correctable unless you install locking hubs.

Good Luck. Its a fair amount of work but its all doable in less than a day.
Click to expand...
Thanks you!! I’m going at it again today. I hope y’all are here through out the day because I’m sure I’ll be posting photos and questions if my issues 😂
 
Mike_H said:
@JMT beat me to it, but you basically have to start from square 1. Get the thing up on jack stands again (at the frame). Get a jack under the front axle. Pull the tires, springs, disconnect the track bar , sway bar, shocks (from the bottom). Pull any bump stop extension you have, pull the jounce bumpers out too. Now, use the jack and move the axle to the "hard stop". It should be the jounce bumper cup and the pad on the axle touching since everything else is disconnected. Now, adjust your control arms (uppers and lowers) to get the bump stop centered up as much as possible and eyeball the pinion angle (you want it to be aproximately pointed at the T-case). You should be able to get it nearly perfect. Don't worry about length or making them "the same." Once you have the axle positioned, check that its square to the frame. If it is, great. If its not, it should take only a minor adjustment.

Now, you get to re-install all the stuff you disconnected, except the springs and tires. You will cycle the axle and make sure the track bar and steering clear your differential. You watch your shocks and when they come close to bottoming out, you need to measure the distance between the jounce bumper cup and the pad. That distance is your bumpstop extension. When you cycle the axle, you need to do full bump (lift the axle horizontally up) and check articulation (each side up when the other side is down). You're making sure the axle can move to its full extents of motion without damaging anything. Finally, once you're convinced you have all the hard parts clearing, throw a tire on and check its clearance to the fenders and flares. Remember to turn it to full lock both directions.

Once you have that done, you'll need to put the springs back in (which generally means disconnecting a couple things again) and then getting the jeep back on its own weight. Now, you'll set pinion angle. Pinion angle takes precedence over caster. At 4" of lift, you should be OK on caster angle. They will be a little vague on center, but it's not really correctable unless you install locking hubs.

Good Luck. Its a fair amount of work but its all doable in less than a day.
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Okay so. First issue. I can’t get my bump stop to center up on the cup. In the photo they’re not touching but, if you were to keep going, it’s going to hit the back of the cup, so I would need to shorten up my lower control arm but! It’s adjusted to the smallest it can get. Idk what else to do.
 
Shaydon15 said:
Thanks you!! I’m going at it again today. I hope y’all are here through out the day because I’m sure I’ll be posting photos and questions if my issues 😂
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We take lunch from 12-1 west coast time but other than that we will be here
 
First thing, pull that rubber jounce bumper out of the bump stop cup. That's just going to get in the way of what you're doing.

Here's a trick if you're going to push the axle up all the way so both ends are on the bump stops. Reconnect the sway bar. That will keep the axle level while you're moving it. I think you said you have quick disconnects, so that shouldn't be hard. (Except it looks like they might not be installed?)

Then, post a photo of where your bump stop cup hits the axle pad. Metal to metal.
 
Also, measure the length of the lower control arm, center of bolt to center of bolt, and tell us what that length is. Are your stock lower arms shorter than that?
 
fuse said:
First thing, pull that rubber jounce bumper out of the bump stop cup. That's just going to get in the way of what you're doing.

Here's a trick if you're going to push the axle up all the way so both ends are on the bump stops. Reconnect the sway bar. That will keep the axle level while you're moving it. I think you said you have quick disconnects, so that shouldn't be hard. (Except it looks like they might not be installed?)

Then, post a photo of where your bump stop cup hits the axle pad. Metal to metal.
Click to expand...
bobthetj03 said:
Also, measure the length of the lower control arm, center of bolt to center of bolt, and tell us what that length is. Are your stock lower arms shorter than that?
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Right now the lower control arms are at random lengths. Like 15 3/8ths. And I have no idea what stock lowers are supposed to be.
 
For reference only, here are the stock control arm lengths:

Front UCA: 15"
Rear UCA: 13.25"
Front/Rear LCA: 15.75"

That's "for reference" because measuring control arm lengths isn't going to solve your problems. But knowing if you're way off might be helpful.
 
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