Mopar LCA swap

[blnewt]

Nice write up TopsOff (can't see your pics though )
I'm a bit surprised your Caster was that low prior to the LCA swap, mine was much closer to 6, maybe mine being a 2 dr. played a role in that???

Did you use any rust breaker spray prior to the job?

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[jmcdtucson]

So is Jay wrong with the 103+50? Where did that come from?

103+50 is for the stock LCA's.
190 is for the Mopar lift LCA's (the ones you installed).

It's the same bolt so I don't understand the different recommendations.

At least that's what I've come up with from reading about 1000 posts on the subject

Nice writeup by the way.

 

[word302]

103+50 is for the stock LCA's.
190 is for the Mopar lift LCA's (the ones you installed).

It's the same bolt so I don't understand the different recommendations.

At least that's what I've come up with from reading about 1000 posts on the subject

Nice writeup by the way.

It's because they are both going to net roughly the same amount of torque.

 

[AnnDee4444]

103+50 is for the stock LCA's.
190 is for the Mopar lift LCA's (the ones you installed).

It's the same bolt so I don't understand the different recommendations.

At least that's what I've come up with from reading about 1000 posts on the subject

Nice writeup by the way.

The 103+50 degrees is the "turn of the nut" method. As I understand it, torquing a bolt isn't as effective at measuring the tensile load as the turn of nut method, because the friction on the threads varies. A crusty old bolt will hit 190 lb-ft of torque far sooner than a new properly lubed bolt. The turn of nut method attempts to take this variable out, by targeting a specific position of the nut rather than torque value. The turn of nut specs you listed are specific to the OEM hardware, as a different thread pitch could mean a different specification.

 

[TopsOff]

Did you use any rust breaker spray prior to the job?

No spray, no issues, but she's still pretty new.

 

[Onward4x4]

I am not sure why FCA is not pushing this easy and cheap fix on all Rubicons, but again they are replacing the whole rear glass because of a small defroster detachment, so there you go.

Rubicon suspension is about 1.5 inches higher than Sahara and Sport, but all three use the same length LCA. Therefore Rubicon has a lower positive caster (typically 4~4.5) while Sahara and Sport have 5~5.5. The low caster affected Rubicon's ability to track straight, return to center, and make other steering components more vulnerable. It gets even worse when installing Mopar lift as they give almost 3", and some forum members reported their casters after lift was in the lower 3.

For stock Rubicon, one cheap fix is to use Mopar 2" lift's LCA since they are slightly longer. It is perfect since too much caster can also cause steering issues. Mopar 2" lift LCAs are about $60 for a pair. This is much cheaper than even a caster bolt or correction bracket. Best of all, the old and new LCA look the same so warranty is preserved with even the pickiest dealer.

For lifted Rubicon, an adjustable LCA (Teraflex, etc.) should be used to correct caster.

Awesome information. Now, do you think the same issue you referred to for a Rubi would also exist in a Sahara with Rubi suspension swap? My Sahara tracking is weird... at times, it is supper straight and good and at times it pulls heavily to the left... If it doesn't go straight, it always pulls to the left never right... So I am perplexed.

 

[blnewt]

Awesome information. Now, do you think the same issue you referred to for a Rubi would also exist in a Sahara with Rubi suspension swap? My Sahara tracking is weird... at times, it is supper straight and good and at times it pulls heavily to the left... If it doesn't go straight, it always pulls to the left never right... So I am perplexed.

Low caster can cause what you're dealing with, more prone to wander off the center, not sure why yours is always prone to wander left, but the fact that it isn't staying locked at center indicates low caster as the primary culprit, especially since you raised your JL.
Caster is roughly decreased by a degree for every inch you lift, so a Rubi swap will lift you in the 1.5 to 1.75" range, decreasing your caster by that 1.5 to 1.75 degree. My JL 2 door sport w/ Rubi 4dr springs wasn't tracking nearly as well prior to the longer Mopar LCAs, having that caster in the 6 degree range (which you will be w/ the Longer LCAs) is the sweet spot for the JL caster. My steering was as perfect as you can get AFAIK when it was stock (w/ the newest Mopar steering damper recall), and getting that caster back up to that range, I was happy again. You will be much happier w/ this upgrade.

 

[word302]

Awesome information. Now, do you think the same issue you referred to for a Rubi would also exist in a Sahara with Rubi suspension swap? My Sahara tracking is weird... at times, it is supper straight and good and at times it pulls heavily to the left... If it doesn't go straight, it always pulls to the left never right... So I am perplexed.

Your tires, pressure, and toe could all be factors as well.

 

[TopsOff]

Follow-up report:

The additional caster changes the wander for the better IMHO, but doesn't eliminate it. Steering forces are higher, especially at the higher speeds. She self centers better out of the slow speed corners - like a 90 degree right turn off a stop sign. With the lower caster I'd have to help it center up in those situations. On the highway she's a bit more sensitive to road crown. I'd say overall she's got a snappier feel. All consistent with what to expect at higher caster settings - but this isn't 'the fix'.

 

[AnnDee4444]

FWIW: The 2-door probably won't respond as much to added caster due to the higher steering ratio.

 

[blnewt]

All consistent with what to expect at higher caster settings - but this isn't 'the fix'.

Not "the fix" for many steering woes, but at least in my case it restored my fine steering back to being fine again after the Rubicon suspension swap. And I would highly recommend this "fix" to anyone that has a Rubicon (with no plans to further lift it) or Sport/Sahara owners that swap to Rubicon suspension or lift 1.5 to 2".

 

[wv18jl]

Great post
Thanks for all who took the time to respond
Did mine today
Went as previously described
Did buy a 3/4" ThunderGun to save my old ass the effort
I always get frustrated by people who say "my seat of the pants ..."
But ...
Does feel noticeably different and more ... solid
No measurable difference, just feels better.

 

[Jmc711]

I might be crazy but the site says the longer arms won't fit my 2020 JL? Any idea why? Is it because it's designed for lift kits?

 

[Keycub]

I might be crazy but the site says the longer arms won't fit my 2020 JL? Any idea why? Is it because it's designed for lift kits?

Fit mine no problem

 

[Jmc711]

Curious as to people's opinion. Have a 2020 JL Sport S. Considering a Rubicon suspension with TF .5" spacers and the longer Mopar LCAs. What kind of lift should I expect? Considering 35s and wondering if it's enough. Probably used 90% as daily driver.

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