JT alignment specs

[RodRecket]

Why do you have both Mopar longer lcas and geometry correction brackets? Did you try it with one and then add the other?

I bought the geo brackets because I wanted the upper and lower control arms as close to stock arm geometry as possible. The brackets move both arms vs just extended lowers. The difference in length between the stock and mopar lift LCAs was small enough (1/4" maybe) that I thought it would be a good combo with the small spacer lift I added up front. The spacer was added make up for the weight of the steel bumper/winch up front.

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[ShadowsPapa]

I'm going to revive this thread instead of creating a new one. My JT drives well and I think I'm in good shape but I am having a hard time letting go of the fact I may be a little "out of spec"

2020 JT Sport S MT on MOPAR 2" lift, teraflex 1" spacer up front, Rancho geometry correction brackets (UCA/LCA), teraflex front track bar, evo rear trackbar.

The only numbers out of spec is my caster. I'm at 7.5 (driver) and 7.3 (passenger)

I have the stock LCAs which are shorter than the mopar kit LCAs and would pull my caster back slightly, does anyone think that's worthwhile? It drives great but my concern is wearing a driveline component out prematurely.

I'm with Mac. And if you decide to remove the MOPAR lift kit lower arms, let me know - I need more caster! ;-) (getting my hint in there)

But seriously, yeah, that's IMO, excessive, but it isn't likely to cause issues other than the fact that going too extreme can cause wobble under certain conditions. Mostly caster makes turns, deviations from straight, harder but extremes can cause issues.

The MOPAR 2" lift on a sport is likely over 2" because it's lighter than the others (I believe MOPAR bases the 2" value on the heavier loaded Rubicon - that's a speculation), plus you have 1" spacers? You likely have over 3" of lift. I'd be for the geometry correcting brackets with that sort of lift, and adjustable lower arms.
DEPENDING on how it drives/steers/handles/BRAKES, etc. - I'd personally, IF IT WAS ME, again, personally, I'd likely reign in the caster a bit. That's me with my experience on other vehicles and trucks (Ford, Chevy, etc.)

 

[ShadowsPapa]

I bought the geo brackets because I wanted the upper and lower control arms as close to stock arm geometry as possible. The brackets move both arms vs just extended lowers. The difference in length between the stock and mopar lift LCAs was small enough (1/4" maybe) that I thought it would be a good combo with the small spacer lift I added up front. The spacer was added make up for the weight of the steel bumper/winch up front.

Resolving the geometry, lowering the frame end of the control arms gets your caster back into range because you level them out again. It's the angle of the arm, they SWING back as the axle is lowered, that reduces caster. Lowering the frame side reduces the caster reduction associated with a lift so likely you only needed the brackets.

 

[RodRecket]

I'm with Mac. And if you decide to remove the MOPAR lift kit lower arms, let me know - I need more caster! ;-) (getting my hint in there)

But seriously, yeah, that's IMO, excessive, but it isn't likely to cause issues other than the fact that going too extreme can cause wobble under certain conditions. Mostly caster makes turns, deviations from straight, harder but extremes can cause issues.

The MOPAR 2" lift on a sport is likely over 2" because it's lighter than the others (I believe MOPAR bases the 2" value on the heavier loaded Rubicon - that's a speculation), plus you have 1" spacers? You likely have over 3" of lift. I'd be for the geometry correcting brackets with that sort of lift, and adjustable lower arms.
DEPENDING on how it drives/steers/handles/BRAKES, etc. - I'd personally, IF IT WAS ME, again, personally, I'd likely reign in the caster a bit. That's me with my experience on other vehicles and trucks (Ford, Chevy, etc.)

Resolving the geometry, lowering the frame end of the control arms gets your caster back into range because you level them out again. It's the angle of the arm, they SWING back as the axle is lowered, that reduces caster. Lowering the frame side reduces the caster reduction associated with a lift so likely you only needed the brackets.

That makes sense. It was kind of a gamble going with the extended arms because the extra length was so minimal I wasn't sure what I'd get. I was aiming for ~ 5.5° - 6.5° of caster based on what I've read from lift manufacturers and others experiences. It drives nicely, I just can't help myself wanting to hit the number I was trying to achieve.

Definitely wanted to make sure I am not at risk of prematurely wearing or damaging anything.

I came across a good deal on a sector shaft brace. I think when I add that I'll make the switch back to stock LCAs

 

[RodRecket]

@ShadowsPapa, when that happens we can work something out to get you the the extended LCAs. I'm north of you in MN.

 

[ShadowsPapa]

That makes sense. It was kind of a gamble going with the extended arms because the extra length was so minimal I wasn't sure what I'd get. I was aiming for ~ 5.5° - 6.5° of caster based on what I've read from lift manufacturers and others experiences. It drives nicely, I just can't help myself wanting to hit the number I was trying to achieve.

Definitely wanted to make sure I am not at risk of prematurely wearing or damaging anything.

I came across a good deal on a sector shaft brace. I think when I add that I'll make the switch back to stock LCAs

Funny thing - I've not read what the lift manufacturers suggest, I was just going on my own experience, gut feeling, adding what I've observed in general and figured "if that was me, I'd probably aim for something around 6" and then I read your post - 5.5-6.5" LOL, I was right in the middle.

ShadowsPapa, when that happens we can work something out to get you the the extended LCAs. I'm north of you in MN.

Hey, neighbor!
Sounds good.

Just curious, maybe I missed it - have you considered, or maybe you've done, a trackbar brace?
Not that it's a must, but it would seem logical that as you go up in lift, you have a bit more sideways force on that bar - you've changed the normal running angle a bit. Again, I'm just drawing it out in my head and thinking if I ever did that much of a lift what I MIGHT do (after some research)

 

[RodRecket]

Funny thing - I've not read what the lift manufacturers suggest, I was just going on my own experience, gut feeling, adding what I've observed in general and figured "if that was me, I'd probably aim for something around 6" and then I read your post - 5.5-6.5" LOL, I was right in the middle.




Hey, neighbor!
Sounds good.

Just curious, maybe I missed it - have you considered, or maybe you've done, a trackbar brace?
Not that it's a must, but it would seem logical that as you go up in lift, you have a bit more sideways force on that bar - you've changed the normal running angle a bit. Again, I'm just drawing it out in my head and thinking if I ever did that much of a lift what I MIGHT do (after some research)

Well as I mentioned above I did come across a synergy track bar and sector shaft brace that I plan on adding. It looks like the only complication to that is the possibility of the teraflex adjustable track bar (already installed) coming into contact with the sector shaft nut. I need to try to find out if anyone has run this combo and if extra bump stop is necessary.

Since I'll have the suspension loosened up to do that install it'll be a good time to swap the LCA's back. Again not because it drives poorly, it really drives well, but because there are typically specified specs for a reason... I just don't have a great understanding of those reasons in this case.

 

[MoparMadness]

Our recommendation would be:
Front Track Bar 2.5” lift – 34 3/16”
Front Lower Control Arms 2.5” lift heights – 24 1/4“
Front Upper Control Arms 2.5” lift heights – 20 7/16”

2.5” Lift Height: 4.8 to 6.35 degrees of Caster with a .2 to .4 Cross Caster Split (.2 to .4 degrees more caster on the pass. side than the driver’s side.)

Tow: 0 to slightly towed in but within factory specifications

I am curious why you have slightly more caster recommended on the passenger side. Mine measures about opposite with 6.0 driver and 5.7 passenger. Thanks

 

[ShadowsPapa]

Can't change caster difference without changing "ball joints". The caster difference, or split, is set once things are welded together.

 

[MoparMadness]

Can't change caster difference without changing "ball joints". The caster difference, or split, is set once things are welded together.

I am aware it would require offset ball joints to change once the axle has been welded. I am just trying to find out why they recommend more caster on the passenger side.

 

[ShadowsPapa]

I am aware it would require offset ball joints to change once the axle has been welded. I am just trying to find out why they recommend more caster on the passenger side.

Perhaps to compensate for road crown? Some areas still have a lot of road with crown and a vehicle aligned symmetrically will pull to the right due to the crown. A vehicle tends to "pull" to the side with less caster - that's the only thing I can think of off the top of my head.

The amount of difference isn't large - I can't think of any other reason other the road crown or "lean" of many highways.

 

[Rock Krawler Suspension]

I am curious why you have slightly more caster recommended on the passenger side. Mine measures about opposite with 6.0 driver and 5.7 passenger. Thanks

@ShadowsPapa is correct. Road crown can be significant in some areas and compensating keeps you from having to hold the wheel to the left in order to go straight.

 

[MoparMadness]

@ShadowsPapa is correct. Road crown can be significant in some areas and compensating keeps you from having to hold the wheel to the left in order to go straight.

Thanks for the information.

 

[ShadowsPapa]

@ShadowsPapa is correct. Road crown can be significant in some areas and compensating keeps you from having to hold the wheel to the left in order to go straight.

It's still rather common around here.
The road in front of my house was blacktopped several years ago and has a significant crown to it.

 

[mbdiesel]

how do you measure caster on the Gladiator? do you need special tools?

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