Alignment Question / Results

[DCRubicon]

Just installed adjustable upper control arms and had Jeep realigned. I already had lowers on there when it was aligned last year.

Running - 2.5 inch teraflex lift with full steer smarts up front and rear track bar bracket. After the shops alignment the car seems to be pulling to the right a ton.

Do these numbers look right?

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[JDM]

The caster on the right is -1* On the right. This seems to be -cross caster on the wrong side. On these specs the Specified range is no difference from left - right. I have seen other specs that show a cross caster Specified Range of .5*. Regardless I would suggest that you try a .5* increase on the right side. Or 7.25*+ on right. Leave the left as is.

 

[rustyshakelford]

Caster is higher than I’d like to see with what you’ve done to your jeep, also toe it low. Steersmart suggests .4-.5° positive.

If you’re good with a tape measure, I’d pull the arms and measure them. Put a jack or something under the pinion and do both lowers at the same time. Ensure they are exactly the same length. You could use RK arm length specifications for their 2.5” lift is teraflex doesn’t supply them. As mentioned, the drivers is typically lower caster than passenger. You’re is backwards. I’d venture to guess you’re axle isn’t sitting exactly square

Brett

 

[JDM]

Caster is higher than I’d like to see with what you’ve done to your jeep, also toe it low. Steersmart suggests .4-.5° positive.

If you’re good with a tape measure, I’d pull the arms and measure them. Put a jack or something under the pinion and do both lowers at the same time. Ensure they are exactly the same length. You could use RK arm length specifications for their 2.5” lift is teraflex doesn’t supply them. As mentioned, the drivers is typically lower caster than passenger. You’re is backwards. I’d venture to guess you’re axle isn’t sitting exactly square

Brett

6.5 - 7 degrees on a Jeep is fine. Cross caster is going to affect pull more than anything else. I’m running mine at 7*+L and 7.25*+R, compensates for the crown on a road. Tracks true like a dream and it’s amazing on turns and corners. Check the tire pressure side to side as well. No excessive tire wear or feathering at all on 33” Grabber ATx tires, no lift.

 

[rustyshakelford]

6.5 - 7 degrees on a Jeep is fine. Cross caster is going to affect pull more than anything else. I’m running mine at 7*+L and 7.25*+R, compensates for the crown on a road. Tracks true like a dream and it’s amazing on turns and corners. Check the tire pressure side to side as well. No excessive tire wear or feathering at all on 33” Grabber ATx tires, no lift.

I like mine around 6.5° on the high end. I don’t want excessive pinion angle. We wheel all over the county and know the negatives of high caster. PSC recommends 7° for some reason and that’s the only time I’ll set them to that. We have our own hunter alignment machine and like to think we have a pretty good grasp on the JL platform. Even then, sometime to much of something good (caster) can become a bad thing. I’m glad your Jeep is driving well but I wouldn’t suggest someone on 2.5” lift to have that high of caster.

Brett

 

[Yellowssm]

Are there ideal alignment specs when lifted or should the alignment place just use stocks specs?

 

[JDM]

I like mine around 6.5° on the high end. I don’t want excessive pinion angle. We wheel all over the county and know the negatives of high caster. PSC recommends 7° for some reason and that’s the only time I’ll set them to that. We have our own hunter alignment machine and like to think we have a pretty good grasp on the JL platform. Even then, sometime to much of something good (caster) can become a bad thing. I’m glad your Jeep is driving well but I wouldn’t suggest someone on 2.5” lift to have that high of caster.

Brett

There in lies the challenge caster and pinion angle. Offroad vs Onroad, and getting the best balance. My alignment was done by a shop that is very familiar with achieving the balance and the pinion angle was checked at 7*+ caster. There is no driveline shake, at all, I also checked for that after the caster was set. If there was any I would have the caster re set. My JLU is not lifted and if I do anything at all it will only be to take the factory rake out. While I do off road it is not serious off road so my JLU is dialled in primarily for on road enthusiastic driving.

In part I went to 7*+ because I will be adding a PSC system to get that #@$! dead spot out. So I wanted to test it, I do things one step at a time. If I were to lift my JLU I would include in the budget drive line work to allow for the pinion angle and the caster to be the best for both, on and off road, if necessary. Not everyone would do that. The shop that has done and will continue to do the work on my JL builds extreme rock crawlers, and participates in rock crawling events. Whenever I consult them they start by saying, “well knowing you, the no compromise recommendation is.....”

So I’m not disagreeing with you or questioning your familiarity with the JL platform and I do feel that 6.5*+ is a good place to be. But for on road, cross caster is necessary IMO.

 

[rustyshakelford]

Are there ideal alignment specs when lifted or should the alignment place just use stocks specs?

There’s not really a good way to answer that without having more details on your Jeep. The factory caster specs are 4.5-5.5°. JLs are very picky when it comes to caster so we sent them in the low to mid 6s. The camber isn’t adjustable until the aftermarket starts releasing adj ball joints which we should be getting in soon to do a little testing with. Toe isn’t really affected when lifting so factory is generally fine. Once you start replacing the tie rod you can fine tune it to what the manufactures suggests.

Brett

 

[Yellowssm]

There’s not really a good way to answer that without having more details on your Jeep. The factory caster specs are 4.5-5.5°. JLs are very picky when it comes to caster so we sent them in the low to mid 6s. The camber isn’t adjustable until the aftermarket starts releasing adj ball joints which we should be getting in soon to do a little testing with. Toe isn’t really affected when lifting so factory is generally fine. Once you start replacing the tie rod you can fine tune it to what the manufactures suggests.

Brett

I just have a metal cloak game changer 2.5” on 35’s. So just make sure caster is mid 6’s?

 

[rustyshakelford]

There in lies the challenge caster and pinion angle. Offroad vs Onroad, and getting the best balance. My alignment was done by a shop that is very familiar with achieving the balance and the pinion angle was checked at 7*+ caster. There is no driveline shake, at all, I also checked for that after the caster was set. If there was any I would have the caster re set. My JLU is not lifted and if I do anything at all it will only be to take the factory rake out. While I do off road it is not serious off road so my JLU is dialled in primarily for on road enthusiastic driving.

In part I went to 7*+ because I will be adding a PSC system to get that #@$! dead spot out. So I wanted to test it, I do things one step at a time. If I were to lift my JLU I would include in the budget drive line work to allow for the pinion angle and the caster to be the best for both, on and off road, if necessary. Not everyone would do that. The shop that has done and will continue to do the work on my JL builds extreme rock crawlers, and participates in rock crawling events. Whenever I consult them they start by saying, “well knowing you, the no compromise recommendation is.....”

So I’m not disagreeing with you or questioning your familiarity with the JL platform and I do feel that 6.5*+ is a good place to be. But for on road, cross caster is necessary IMO.

Cross caster is absolutely necessary. You won’t feel the driveline vibration if you have it until you’re in 4wd because the driveshaft isn’t spinning. If you swapped to a one piece rcv, the pinion angle would very much be a subject of concern. Being that you’re stock height, the angles don’t affect you in the way the OP would at lifted height. Since your factory sahara height vs his lifted rubicon (~3.5-4” difference) it’s really apples to organges comparison.

Seems like you know what to expect when and if you lift which makes the shops job much easier. The psc will remove the dead spot as it replaces everything. If you’re not going to wheel it, you can just get the pump and gear box. No need for the ram. Can’t remember which package they call that. The PSC stuff is great.

Brett

 

[rustyshakelford]

I just have a metal cloak game changer 2.5” on 35’s. So just make sure caster is mid 6’s?

That’s my suggestion!

Brett

 

[JDM]

Cross caster is absolutely necessary. You won’t feel the driveline vibration if you have it until you’re in 4wd because the driveshaft isn’t spinning. If you swapped to a one piece rcv, the pinion angle would very much be a subject of concern. Being that you’re stock height, the angles don’t affect you in the way the OP would at lifted height. Since your factory sahara height vs his lifted rubicon (~3.5-4” difference) it’s really apples to organges comparison.

Seems like you know what to expect when and if you lift which makes the shops job much easier. The psc will remove the dead spot as it replaces everything. If you’re not going to wheel it, you can just get the pump and gear box. No need for the ram. Can’t remember which package they call that. The PSC stuff is great.

Brett

Yes looking forward to getting rid of the dead spot. I did have it in 4wd after the alignment, no vibration. Used to manage a H.D. Frame & Alignment shop in my earlier years. Would modify tandem axle H.D. Trucks for off road work. Barge would take them to the location and they would make roads. Came back in pieces. Lots O fun. Had to be very creative with pinion angles on the tandems. But that was some time ago and it gives me some basis for what I’m doing.

Had a JK and liked it, didn’t have to do a thing on it. I hated the JLU until I started to work out the initial problems. Now, after all the work... love it.

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