Mopar LCA swap

[Solidaxle]

Thanks. I didn’t have access to those instructions, I went by the torque specs posted by @JAY in the sticky thread in the DIY forum. 190 ft/lbs is “as tight as you can get it” in my garage. Lol.

So,
Are all of those specs incorrect that Jay has listed? I was about to use those until I found out about the Mopar instructions. 190lbs

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[Chocolate Thunder]

So,
Are all of those specs incorrect that Jay has listed? I was about to use those until I found out about the Mopar instructions. 190lbs

I don’t know. I used blue Loctite and torqued them down “good and tight”. I checked a few weeks later and they were still good and tight, I was satisfied. Lol.

I think I went with 190 and called it a day.

 

[Stickerhead]

Ok. Just added the Mopar 1/4” longer control arms on my Rubicon with a RE space lift. So on a flat spot the diff cover, I was negative 2.5-3 degrees from 90 degrees. After installing the Mopar LCA’s, it is now at 90degrees on my angle finder. Is the JL the same as the JK where 90 degrees is 6 degrees of caster? I know when I had 4WP check alignment after the lift, it was at 3 degrees caster. So this sounds right and it does drive better. It does not wander like it did before. I need to have the dealership take some of the play out of the steering wheel and it should be perfect. I can tell you the Falcon Nexus shock did nothing but it is a nice upgrade. I have a Teraflex trackbar coming to center the axle and that should do it!

 

[JimmyDoom]

Here's why I chose the Mopar lift arms for my JLR
- Inexpensive
- OEM quality & fit
- Dealer can't tell I've done anything, so I doubt it would ever void any warranty or insurance claims
- non-adjustable 6° of caster can't ever go out of adjustment
- don't plan on lifting

The change is very subtle, but I do find that I am more comfortable above 65 MPH than with OEM caster.

The only thing I'm concerned with is the OEM quality. Not a fan of the quality in the steering components, so If I'm going to change the LCA's, I want them beefier and to have better bushings. There are many options out there and they vary from 1.5" dia (Metal Cloak) up to 2" square (Clayton).
At this point, I don't care about the money, I just want it to drive better.

 

[Stickerhead]

You can buy a whole lotta these arms for what adjustables cost!

 

[AnnDee4444]

The only thing I'm concerned with is the OEM quality. Not a fan of the quality in the steering components, so If I'm going to change the LCA's, I want them beefier and to have better bushings. There are many options out there and they vary from 1.5" dia (Metal Cloak) up to 2" square (Clayton).
At this point, I don't care about the money, I just want it to drive better.

I don't think you should be concerned with the OEM control arm quality, and the only design flaw I see in them is that they are too short to get a proper alignment (which the Mopar arms can fix depending on your ride height). The Mopar/OEM bushings and strength of the arms are not the cause of the JL's steering issues.


I would only suggest aftermarket lower control arms for a few reasons:

1. your ride height makes your desired caster not possible with OEM parts
2. the aftermarket arms offer greater articulation (also consider different bushings in the OEM arms as an alternative)
3. heavy tires/axle or driving style dictate stronger components
4. bling factor

 

[JimmyDoom]

So I'm having a problem understanding this and hope someone can explain it to me.
Mopar sells Rubicon LCA's which are longer then the sport and Sahara ones do to the Rubicon being lifted higher.
The longer LCA's are suppose to correct the caster to bring it in to the correct angle to help with the "wondering" issue.
If Mopar and the FCA are aware of this and they know they should be longer (obviously because they offer them), why are they not installed on all Rubicons from the factory? Why don't they have a recall to do this for all Rubicons released with short arms to replace them?
Without a recall, it forces us to spend our money to buy a part that should have been installed on it from the beginning.
People are saying to just buy them because they are the cheapest. My point is, why should I have to?
Does this make sense to anybody? Am i missing something here?

 

[Chocolate Thunder]

So I'm having a problem understanding this and hope someone can explain it to me.
Mopar sells Rubicon LCA's which are longer then the sport and Sahara ones do to the Rubicon being lifted higher.
The longer LCA's are suppose to correct the caster to bring it in to the correct angle to help with the "wondering" issue.
If Mopar and the FCA are aware of this and they know they should be longer (obviously because they offer them), why are they not installed on all Rubicons from the factory? Why don't they have a recall to do this for all Rubicons released with short arms to replace them?
Without a recall, it forces us to spend our money to buy a part that should have been installed on it from the beginning.
People are saying to just buy them because they are the cheapest. My point is, why should I have to?
Does this make sense to anybody? Am i missing something here?

The longer Mopar arms are not Rubicon specific. They are part of the 2” Mopar lift kit. But they help increase caster for non lifted vehicles which helps somewhat with the wandering steering so some people use them for that purpose. FCA engineering doesn’t acknowledge that longer arms/more caster is needed on stock height vehicles. They’re cool with the wonky steering and refuse to say anything is wrong with it inmost cases. Some whose lift kit doesn’t include longer arms (like Dynatrac) use them as well to make steering more stable.

 

[JimmyDoom]

The longer Mopar arms are not Rubicon specific. They are part of the 2” Mopar lift kit. But they help increase caster for non lifted vehicles which helps somewhat with the wandering steering so some people use them for that purpose. FCA engineering doesn’t acknowledge that longer arms/more caster is needed on stock height vehicles. They’re cool with the wonky steering and refuse to say anything is wrong with it inmost cases. Some whose lift kit doesn’t include longer arms (like Dynatrac) use them as well to make steering more stable.

But the stock height on the Rubicons are about 2" higher then the stock sport or Sahara so that inherently changes the caster angle which should require longer arms to correct the angle.

 

[AnnDee4444]

But the stock height on the Rubicons are about 2" higher then the stock sport or Sahara so that inherently changes the caster angle which should require longer arms to correct the angle.

That's the problem. Jeep did not redesign the lower control arms for the Rubicon, and used the same components as the Sport/Sahara. Instead they just revised the alignment requirements for each model so that the caster was "within spec". There is no logical reason for the Rubicon to have lower caster than the Sport, it was purely a cost-saving method.

Even though the Mopar lift would leave me wanting more caster, we got lucky that the lower control arms happen to be just about right for a stock height Rubicon.

 

[JimmyDoom]

That's the problem. Jeep did not redesign the lower control arms for the Rubicon, and used the same components as the Sport/Sahara. Instead they just revised the alignment requirements for each model so that the caster was "within spec". There is no logical reason for the Rubicon to have lower caster than the Sport, it was purely a cost-saving method.

Even though the Mopar lift would leave me wanting more caster, we got lucky that the lower control arms happen to be just about right for a stock height Rubicon.

Now that just seems silly to revise the alignment requirements just so you can make spec....I wish I could do that at work haha. I understand it's a cost saving thing, but I would also think they would be concerned with making it right.
Do you know the caster angle on the sport and Sahara?
So you put the Mopar lift on yours but didn't change the LCA's? What is your caster angle?

 

[Chocolate Thunder]

Now that just seems silly to revise the alignment requirements just so you can make spec... I would also think they would be concerned with making it right.

You'd be wrong about that. They’re concerned with selling as many of them as possible. The length of the LCA on a Rubicon vs other models is not a deciding factor for anyone.

 

[maweber]

Is there a means to measure caster without taking it to an alignment shop? I am surmising that throwing a Rubi suspension on a Sport would be benefit from the longer LCAs, correct?

 

[oceanblue2019]

Is there a means to measure caster without taking it to an alignment shop? I am surmising that throwing a Rubi suspension on a Sport would be benefit from the longer LCAs, correct?

Correct, anything running the Rubicon spring and therefore a modest lift will loose caster with the stock LCA. Adding the Mopar longer LCA will help solve that.

On a Rubicon you get right around 6 degrees with the Mopar longer LCA; which is right about where you want it to be. With the standard arm it's around 4 degrees which is sub-optimal.

 

[californiajeeping]

Is there a means to measure caster without taking it to an alignment shop? I am surmising that throwing a Rubi suspension on a Sport would be benefit from the longer LCAs, correct?

Search YouTube for measure caster angle and you will see several how to videos. You can pay an alignment shop for a "report only" alignment, which is usually $19. But if you want them to make an adjustment, then they charge the regular higher rate.

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