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Discussion Starter #1
I recently installed Rancho geometry brackets on my 2017 Jeep jku due to the "wandering" you typically get with a lifted Jeep. I am not positive on the lift size (I did not install, bought car used) but I would estimate at 3 or 3.5", and I am running 35" tires.
I took the Jeep in for an alignment to check numbers, and here's where I'm at:
Caster 6.8 left, 6.6 right. Toe is .17 for left, and .17 for right.
With the Rancho brackets I have some adjust-ability with 4 hole locations for the upper CA. I currently have it in the 2nd from bottom hole (I would assume the farther I drop the upper control arm by attaching to the lower holes on the bracket, I am increasing caster).
2 question: Is that caster too high? and does that toe seem right?

Thanks for any help!
Dave
 

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I would raise it to top hole. That's too much caster. I would lower toe in as well
 

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Typical caster is around 5 degrees, give or take a half degree.
With the brackets each hole further down means more caster. You may have a little too much, but to each their own.
How does it drive now? I would think you likely have a 2.5" lift to fit 35's. I think on the Rancho brackets they recommend the second hole from the top for a 2.5" lift. Of course, every Jeep is different. Like snowflakes.....
 

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Thanks for the feedback. I would say it drives pretty good, maybe a little drifting with freeway speeds, but nothing terrible.
I think I'll take your advice and move up a hole or 2 on the bracket and see what that feels like.
Will running a caster at almost 7 cause any problems for the Jeep? Unnatural wearing etc?
 

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I recently installed Rancho geometry brackets on my 2017 Jeep jku due to the "wandering" you typically get with a lifted Jeep. I am not positive on the lift size (I did not install, bought car used) but I would estimate at 3 or 3.5", and I am running 35" tires.
I took the Jeep in for an alignment to check numbers, and here's where I'm at:
Caster 6.8 left, 6.6 right. Toe is .17 for left, and .17 for right.
With the Rancho brackets I have some adjust-ability with 4 hole locations for the upper CA. I currently have it in the 2nd from bottom hole (I would assume the farther I drop the upper control arm by attaching to the lower holes on the bracket, I am increasing caster).
2 question: Is that caster too high? and does that toe seem right?

Thanks for any help!
Dave
Since you have options, definitely go up one hole and decrease caster then adjust toe to about .08 or .09 per side. I like total toe to be between .16 and .20.
 

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Thanks for the feedback. I would say it drives pretty good, maybe a little drifting with freeway speeds, but nothing terrible.
I think I'll take your advice and move up a hole or 2 on the bracket and see what that feels like.
Will running a caster at almost 7 cause any problems for the Jeep? Unnatural wearing etc?
My experience with too much caster was it slowed the steering down and sorta made the Jeep drive like a Cadillac land yacht from the 70's. It had a dead spot in the center of steering where I could move the steering wheel back and forth while going straight.
But I don't think it caused any physical issues or increased wear.
 

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My experience with too much caster was it slowed the steering down and sorta made the Jeep drive like a Cadillac land yacht from the 70's. It had a dead spot in the center of steering where I could move the steering wheel back and forth while going straight.
But I don't think it caused any physical issues or increased wear.
I guess I have always worried about driveshaft with that much caster unless you have an axle that has built in caster correction for taller lifts.
 

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I guess I have always worried about driveshaft with that much caster unless you have an axle that has built in caster correction for taller lifts.
Good point. The stock drive shafts don't seem to care too much but an aftermarket drive shaft does care about pinion angle. Maybe as you lift higher that would become more of an issue, though, as even with correct caster at the axle as you lift the drive shaft to pinion angle is increasing. And too much caster is going to increase that angle in the same direction that lifting does (i.e., the pinion is pointing lower than at the TC output).
Having 2 degrees too much caster means having two degrees extra of angle in the drive shaft / pinion relationship. Ideally the drive shaft would be near in-line with the pinion angle.
 

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I recently installed Rancho geometry brackets on my 2017 Jeep jku due to the "wandering" you typically get with a lifted Jeep. I am not positive on the lift size (I did not install, bought car used) but I would estimate at 3 or 3.5", and I am running 35" tires.
I took the Jeep in for an alignment to check numbers, and here's where I'm at:
Caster 6.8 left, 6.6 right. Toe is .17 for left, and .17 for right.
With the Rancho brackets I have some adjust-ability with 4 hole locations for the upper CA. I currently have it in the 2nd from bottom hole (I would assume the farther I drop the upper control arm by attaching to the lower holes on the bracket, I am increasing caster).
2 question: Is that caster too high? and does that toe seem right?

Thanks for any help!
Dave
According to Rancho you have a 2" lift.

 

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I had the Rancho brackets but I sold them for the AEVs because I was in between caster settings with an AEV 2.5" lift.

Here were my after lift alignment numbers. (i did adjust the toe 1/8" total)

 

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I had the Rancho brackets but I sold them for the AEVs because I was in between caster settings with an AEV 2.5" lift.

Here were my after lift alignment numbers. (i did adjust the toe 1/8" total)

From there, moving one hole down would have had you at a near perfect 4.8-4.9 deg.
 
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Yeah AEV advised (and you previously) about moving to the center hole.
Probably do it when the weather warms up.

Here is what AEV said when I asked about expected Caster.

Just installed my 2.5" Dualsport lift and I adjusted the Steering and Toe(about 1/16").

Just to confirm I took it to my local 4 x 4 shop to have the alignment "checked".

On the AEV 2.5" lift what is the expected Caster value using the top hole in the AEV correction brackets?

Here is the report.


Great question Vanhalo!

We don't have an expected caster measurement because of all the variability. That measurement is going to vary a bit depending on the weight of the vehicle. For example: a JK with our steel bumpers, a hard top, and loaded with a lot of gear will have a different value than a Jeep with factory plastic bumpers, a soft top, and no gear. It's possible that you might actually sit a bit taller than the spec for the kit. You might benefit from the middle hole to increase the caster if the steering feels a little "flighty", but it's not 100% required. We recommend this if it feels a little squirrely going down the road
.
 

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Discussion Starter #14
According to Rancho you have a 2" lift.

If I'm reading that chart correctly, wouldn't that mean i have a 3" lift. I'm currently on the 3rd of 4 holes and my caster is 6.7.
So the question is whether I back to the 2nd hole for 5.5 caster, or the top hole for 4.5. Looks like Rancho recommends either.
Before I put the bracket on the car was very "flighty" so i'm nervous to decrease the caster too much...
advice?
 

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If I'm reading that chart correctly, wouldn't that mean i have a 3" lift. I'm currently on the 3rd of 4 holes and my caster is 6.7.
So the question is whether I back to the 2nd hole for 5.5 caster, or the top hole for 4.5. Looks like Rancho recommends either.
Before I put the bracket on the car was very "flighty" so i'm nervous to decrease the caster too much...
advice?
i misread your comment.
I thought you meant the 2nd hole.
yes you are correct....3" inch lift according to Rancho.
6.7 Caster
1st hole looks like the correct setting @ 4.5/0.0
 

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If I'm reading that chart correctly, wouldn't that mean i have a 3" lift. I'm currently on the 3rd of 4 holes and my caster is 6.7.
So the question is whether I back to the 2nd hole for 5.5 caster, or the top hole for 4.5. Looks like Rancho recommends either.
Before I put the bracket on the car was very "flighty" so i'm nervous to decrease the caster too much...
advice?
Likely it is a "2.5 inch" lift. Typically 2.5" lifts deliver around 3" of lift up front and less in back. That helps level the rake that Jeeps come with stock.
I would try one hole back, to the second hole, and see how it works. But even the first hole can make a fair amount of difference vs no bracket.
 
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