Front LCA installation help

[Blacktip]

Stock JLUR XR. I am going to replace the front LCA with Metal Cloak adjustable LCA, and I have couple of questions.

My goal is to set the caster angle to 6.5 degree initially, some suggest 6 degrees and others suggest 7 degrees, so I am aiming for in between.

How long should I set the length of the LCA? I am thinking 3/8" or 1/2" longer than stock

To install longer LCA, the front axle must rotate forward. How can I rotate or push the axle forward?

Should I install one LCA at a time, or take both out then proceed with the installation.

What location should I use to measure the caster angle? Can I use a phone app for this?

Where should I lift and place my jack stands?

I watched many videos, but each and everyone was different.

Sorry for too many questions. This will be the first time to work on a Jeep. It is only 150 miles young.

Thanks,

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[Howardlv22]

Bump, someone here will have the answers lots of smart dudes and women here ??

 

[hoag4147]

Stock JLUR XR. I am going to replace the front LCA with Metal Cloak adjustable LCA, and I have couple of questions.

My goal is to set the caster angle to 6.5 degree initially, some suggest 6 degrees and others suggest 7 degrees, so I am aiming for in between.

How long should I set the length of the LCA? I am thinking 3/8" or 1/2" longer than stock

To install longer LCA, the front axle must rotate forward. How can I rotate or push the axle forward?

Should I install one LCA at a time, or take both out then proceed with the installation.

What location should I use to measure the caster angle? Can I use a phone app for this?

Where should I lift and place my jack stands?

I watched many videos, but each and everyone was different.

Sorry for too many questions. This will be the first time to work on a Jeep. It is only 150 miles young.

Thanks,

IMO 24.5” would be a little too much if you are shooting for 6.5 caster and not lifting. I have an XR with 2.5” spacer in front and I set my RK LCAs to 24.5” and my caster is 6.5. I would go no more then 3/8” over stock. You should do each side one by one on the ground. Don’t put Jeep on jack stands, at least not when torquing everything down. As for self measurement, a cheap angle finder works well or if you phone app, place on front of axle housing at the two indentations https://www.jlwranglerforums.com/forum/threads/jl-rubicon-caster-measure.25691/#post-639232

 

[Jmos4]

Hi,

I installed the MOPAR 2" LCA'S, on my 22, support the frame let axle hang, do one at a time a rachet strap helps get things realigned to reassemble.

As for length match what you have and add extra length believe stock LCA'S are 1/4" shorter than the 2" LCA'S.

If you look on here from the 2" LCA'S it details on how to verify angle and length of arms.

Goodluck one of the best mods to do on a newer JL

Regards,
Jim

 

[Blacktip]

IMO 24.5” would be a little too much if you are shooting for 6.5 caster and not lifting. I have an XR with 2.5” spacer in front and I set my RK LCAs to 24.5” and my caster is 6.5. I would go no more then 3/8” over stock. You should do each side one by one on the ground. Don’t put Jeep on jack stands, at least not when torquing everything down. As for self measurement, a cheap angle finder works well or if you phone app, place on front of axle housing at the two indentations https://www.jlwranglerforums.com/forum/threads/jl-rubicon-caster-measure.25691/#post-639232

Thanks for the reply. If the Jeep is on the ground, how can I align the LCA installation holes?

 

[garyji]

Can I ask why you think you need to replace parts on a brand new Rubi XR???

G.

 

[Blacktip]

Can I ask why you think you need to replace parts on a brand new Rubi XR???

G.

to improve steering feel.

 

[hoag4147]

Thanks for the reply. If the Jeep is on the ground, how can I align the LCA installation holes?

Many different ways but since just extending about 3/8” you can roll tire a bit to get aligned. This also why it’s a good reason to do one side at a time. Here is a decent video showing (little long and wordy lol) Go to about 15 min mark to see what I referenced.

 

[Jmos4]

Hi again,

Align arms and holes while you have the Jeep supported on the Frame, after you have both arms in place set Jeep on all 4 tires and then torque bolts to spec.

Regards,
Jim

 

[stumblinhorse]

Torquing to spec, 190ft/lbs, on the ground under the Jeep is a tall order. I paid the price for a few days after it did that on mine. I would “try” to support the axles on jack stands to give yourself some more room to tighten. Otherwise put on a weightlifter belt or something before you shoot your inerds out of your body

 

[snapper692]

Torquing to spec, 190ft/lbs, on the ground under the Jeep is a tall order. I paid the price for a few days after it did that on mine. I would “try” to support the axles on jack stands to give yourself some more room to tighten. Otherwise put on a weightlifter belt or something before you shoot your inerds out of your body

Totally this.....Getting old sucks! lol

 

[Beachcomber72]

to improve steering feel.

You’re not going to feel any “steering” difference by doing this. Are you having steering problems?

 

[stumblinhorse]

You’re not going to feel any “steering” difference by doing this. Are you having steering problems?

People’s definition of feel are different. lengthening front LCAs by 3/8” will definitely change the “return to center“ of the steering and the Jeep’s tendency to go straight. It will not change the effort it takes to turn the wheel.

So feel? Not sure. But you will “feel“ 190 frickin ft/lbs…

 

[DOOKEY]

My goal is to set the caster angle to 6.5 degree initially, some suggest 6 degrees and others suggest 7 degrees, so I am aiming for in between.

Take your Jeep to an alignment shop that does free diagnosis with computer print out. Up to you if you'd like them to set the toe since they are taking the time to help you out. This will help you get your before measurement of caster. Once you're back home use a digital angle finder to get your before measurement. Pick the same spot on the axle before and after the adjustable control arms are installed so you can compare. Now you can get really close on your after measurement without guessing.



To install longer LCA, the front axle must rotate forward. How can I rotate or push the axle forward?

I use my good ole jack with a 2x4 under the pinion flange. Mind you... my floor jack is 4ft. long and not a bottle or the stocker crap so mine works really well. The jack will hold the pinion up while you remove the stock lower control arms. Lowering the jack will rotate the pinion down and move the lower control arm brackets forward so you can adjust accordingly. If you use my suggestion above and have the digital angle finder you can use the jack to get the after measurement you want and then adjust the new LCA's to the length needed.

Should I install one LCA at a time, or take both out then proceed with the installation.

I do both at the same time since the jack is holding the pinion.

What location should I use to measure the caster angle? Can I use a phone app for this?

See above.

Where should I lift and place my jack stands?

Under the tubes out by the knuckles.

I watched many videos, but each and everyone was different.

That's because we all think different. Just remember... Jeeps can be replaced. Fingers and toes can't. So don't lose track of your common sense just because someone else on the internet told you to.

Sorry for too many questions. This will be the first time to work on a Jeep. It is only 150 miles young.

Ask more questions and don't be afraid to. I'm proud of you for taking this on by yourself. One of my biggest accomplishments has been my desire to learn and you have that now. Just take your time and don't lose yer finger.

 

[DOOKEY]

You’re not going to feel any “steering” difference by doing this.

I did.

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