Lower control arms. How to determine new length needed for lift?

[Deleted member 30519]

Anyone know a good option for control arms with the rc 3.5" lift. I only see they make the relocation brackets.

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[LostWoods]

@Gladiator847 I'm quickly turning into a Metalcloak brand whore but Clayton's look really good too. Just depends on what you want out of the joints. I think Clayton's are generally more durable but Metalcloak's have better articulation.


Also just on the original topic from a former alignment/suspension tech, when it comes to setting your arms, length is generally meaningless as long as they are set together correctly and you don't have rubbing. Start with 1/4" as suggested on the lower, set the top to get the correct pinion angle, then get the alignment measured to see where you are.

 

[Andrew05LJR]

Length is a byproduct of caster degree, so dont get fixated on the length of the arm. If 1/4" gets you in the best caster possible, then so be it. AS mentioned, get it on an alignment rack to make the best decision

 

[ShadowsPapa]

Swing into your nearest dealer with a tape measure.

I would but we're well out of town, nearest dealer is 30 minutes away, and they have NO Overland. In fact, all the dealers around here have are Sport versions.

>> Length is a byproduct of caster degree, so dont get fixated on the length of the arm. If 1/4" gets you in the best caster possible, then so be it. AS mentioned, get it on an alignment rack to make the best decision <<

Actually caster is the byproduct of the control arm length.
More length of the lower arm adds caster IF all else is the same.

The arms swing in an arc as the axle moves from the frame so a longer lower arm compensates adding caster back.

The only way to know what length is really needed is the alignment rack for sure.
A 2" lift on one JT may not get you 2" of height change compared to a different model JT. So you can't say "a xx" lift needs xx" longer arms" - that's just a general, generic rule because a 2" lift isn't necessarily a 2" lift for everyone and these do seem to vary a bit in caster right out of the factory.

 

[brianinca]

What is your current caster? I took my brand new JTR in to my suspension shop and they just shook their head and told me "not enough caster, too much toe in, come back in 10,000 miles" and didn't even charge me. Looking at the factory range spec, I've got more caster than the maximum, let alone minimum. 6.1 deg after, the factory specs say 3.45 - 5.45. They didn't turn a hair when I came back and asked for an alignment after I put the longer LCA's on.

All I know is that it has been drivable despite the crummy gearbox performance. Dropping the tire pressure a lot and excessive caster makes 500 mile trips do-able. I look forward to the new box!

Doing one at a time you don't even have to struggle as they are right down there accessible without busting your back, head or arm.
I may go that route one day but in my situation I think my winch and bumper and skid plate offset a lot of the lift.
Wish I could find someone who would measure a bone-stock overland up to the bottom of the fender opening to see how mine compares. I lost my notes that I took a year ago when I measured stock height to see how much payload set the truck down. Bummer.
I added Rubicon springs which gained me about an inch as measured at the bumper, likely a bit less at the wheel, then put on the winch, skid plate and bumper that dropped it about a half inch, the put 3/4" spacers under it and lost track of the STOCK setting to see how much different it sits now from bone stock.
If there's enough difference I'm considering the lower control arms to add some caster back.

 

[ShadowsPapa]

What is your current caster? I took my brand new JTR in to my suspension shop and they just shook their head and told me "not enough caster, too much toe in, come back in 10,000 miles" and didn't even charge me. Looking at the factory range spec, I've got more caster than the maximum, let alone minimum. 6.1 deg after, the factory specs say 3.45 - 5.45. They didn't turn a hair when I came back and asked for an alignment after I put the longer LCA's on.

All I know is that it has been drivable despite the crummy gearbox performance. Dropping the tire pressure a lot and excessive caster makes 500 mile trips do-able. I look forward to the new box!

I've not had mine checked. I asked the dealership shop about it and they said mine should be fine (they are the ones that replaced the steering gear although they never said a thing about checking alignment)
I can see these desiring more - larger diameter tires, and certain other alignment numbers being quite different from other vehicles - and unchangeable in most cases, like camber.
When you look at any troubleshooting chart in books over the years for "front end shimmy", in order of most likely at the top, moving down to least likely - inadequate caster is right below tires, then wheels. Not enough caster, or negative caster, either way, can lead to shimmy or wandering.
Unless the thing is a beast to steer or has any instability, I'd be happy with the 5-6.
Negative or too little leads to wander, positive only increases steering effort (for the most part)

 

[brianinca]

Yeah, I can feel the steering is a little heavier but it's reassuring heavy!

I've no plans to swap back to stock arms, whatever lift I talk my wife into will be fully adjustable.

Mopar dropped the ball on their lift, too basic for the $$. Happy to have benefited from inexpensive parts, though!

I've not had mine checked. I asked the dealership shop about it and they said mine should be fine (they are the ones that replaced the steering gear although they never said a thing about checking alignment)
I can see these desiring more - larger diameter tires, and certain other alignment numbers being quite different from other vehicles - and unchangeable in most cases, like camber.
When you look at any troubleshooting chart in books over the years for "front end shimmy", in order of most likely at the top, moving down to least likely - inadequate caster is right below tires, then wheels. Not enough caster, or negative caster, either way, can lead to shimmy or wandering.
Unless the thing is a beast to steer or has any instability, I'd be happy with the 5-6.
Negative or too little leads to wander, positive only increases steering effort (for the most part)

 

[NCLife]

Anyone know the length of the stock front LCA's on a Mojave? They may be the same on all Gladiators stock. I have Teraflex adjustable LCA's up front, but added the AEV geometry correction brackets and now need to dial back the length of the LCA's.

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