Mopar LCA swap

[BuffaloBill]

Ok so you are now and before at .125" or 1/8" TOE IN?

I just saw the 0.21 degree in the pic Carbonsteel posted. I have not measured mine yet.

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[Jabarsetti]

About ready to tackle this. From what I gather use standard not metric, I have a Milwaukee m18 impact will this be enough to break the bolts loose? Also should I try to get ramps, I have a 2 inch on 35s? Any other suggestions on techniques or tools that would help ?

 

[blnewt]

About ready to tackle this. From what I gather use standard not metric, I have a Milwaukee m18 impact will this be enough to break the bolts loose? Also should I try to get ramps, I have a 2 inch on 35s? Any other suggestions on techniques or tools that would help ?

If you haven't seen my install post here it is, and I would go w/ ramps, huge help w/ this install, and that 2ft breaker should suffice for breaking those nuts loose, I had to add my floorjack pipe to my breaker bar for 1 bolt though. Also spraying the bolts 24 hrs prior w/ a rust breaker, like PB Blast will help quite a bit. And yes, those SAE sizes are the best fit on those bad boys!
https://www.jlwranglerforums.com/forum/threads/rubicon-suspension-on-2-door-sport.40700/#post-919317

 

[Jabarsetti]

If you haven't seen my install post here it is, and I would go w/ ramps, huge help w/ this install, and that 2ft breaker should suffice for breaking those nuts loose, I had to add my floorjack pipe to my breaker bar for 1 bolt though. Also spraying the bolts 24 hrs prior w/ a rust breaker, like PB Blast will help quite a bit. And yes, those SAE sizes are the best fit on those bad boys!
https://www.jlwranglerforums.com/forum/threads/rubicon-suspension-on-2-door-sport.40700/#post-919317

Yes, going off your post. I’m gonna see if O’Reilys loans ramps.

 

[Jabarsetti]

Ok Job done, damn those bolts aren’t fun. The M18 impact with about an hr of Bolts soaked on PB blast did the job for the most part. Breaker bar did the rest and Ramps made it way easier to get leverage. We’ll see if it helps at all. I measured on the front side of the Diff, is that correct? I couldn’t get the bubble magnet to sit level on the rear. Looks like I’m at 90*

 

[FlashGordon]

Great write up and based on the suggestion of many this is a must do inexpensive mod for the Rubicon that frankly should have been done at the factory. @blnewt thanks for the advice on the TSB thread and I have started doing more research and will be doing this soon. Stock JLUR and getting the new steering gear box installed on Wed. I have seen a few members give estimates on the new caster readings but many of the people also have changed or modified their steering or suspension. Can anyone with a stock JLUR confirm your caster reading both before and after installing these Mopar lift LCA's?

 

[blnewt]

Great write up and based on the suggestion of many this is a must do inexpensive mod for the Rubicon that frankly should have been done at the factory. @blnewt thanks for the advice on the TSB thread and I have started doing more research and will be doing this soon. Stock JLUR and getting the new steering gear box installed on Wed. I have seen a few members give estimates on the new caster readings but many of the people also have changed or modified their steering or suspension. Can anyone with a stock JLUR confirm your caster reading both before and after installing these Mopar lift LCA's?

Just going by memory the base caster readings on stock JLUR and JLRs are in the high 3 to mid 4 degree range, and the new LCAs add an additional 1.5 to 2 degrees caster.

Keep in mind there will be slight differences based on the option pkgs on the Rubicons but that range covers that. Expect to be at least mid 5 degrees after the LCA addition.

Now c'mon actual Rubi owners, please confirm for the man!

 

[WagzDad]

2018 JLUR stock 4.8*
with mopar lift LOWER LCAs 6.7-6.8*
added 0.75 spacers to front 6.2*

this is how I measured:
http://www.keep-your-car.com/WebRoo...4846/C0A8/2935/2299/77066_Instructions_GB.pdf

 

[G13]

I am also following the Steering Box TSB threads, and finally installed Mopar LCA on my stock 2020 JLUR today. Thanks to @blnewt and all others contributed tips, it went smooth, although I spent almost 3 hours. And sorry @FlashGordon that I didn’t measure anything before and after.

Removing the stock LCAs took lots of time due to the tight space under the Jeep. I had ramps to lift front, but 2ft breaker bar had not enough space to put force onto it, especially the rear side bolts. I used a floor jack to lift a breaker bar to start the bolts moving. I have a 2ft torque wrench and it was very helpful for both removing and installing new ones.

When I put the new LCA, the bolt hole was not aligned, so I jacked the frame as someone suggested. When I was removing the old LCA on the other side, bolt wouldn’t come out, lifting frame on that side didn’t help, so I lifted the other side (already installed longer LCA on the side) and that moved it to loosen the bolts. As for installing the new longer LCA, I had to switch the jack to the installing side again to align the hole.

Torquing bolts was the hardest part. Front bolts were easier, because they were reachable from front and lifted more. Rear ones were torqued using a floor jack again.

Quick drive with new longer LCA felt more solid and straight (city drive only), and it made somewhat clear that slight wandering my Jeep has is not fixable with aftermarket adjustable LCAs. I have plenty of time left with warranty, so I will wait a little more to see how the new Steel Steering Box works and how dealers handle claims.

After 3 hours of muscle workout, I am very happy with the result. If I have to do this again, I would invest some money into power tools, or rental of them. Thanks again everyone who contributed to this and other threads.

 

[jmcdtucson]

I am also following the Steering Box TSB threads, and finally installed Mopar LCA on my stock 2020 JLUR today. Thanks to @blnewt and all others contributed tips, it went smooth, although I spent almost 3 hours. And sorry @FlashGordon that I didn’t measure anything before and after.

Removing the stock LCAs took lots of time due to the tight space under the Jeep. I had ramps to lift front, but 2ft breaker bar had not enough space to put force onto it, especially the rear side bolts. I used a floor jack to lift a breaker bar to start the bolts moving. I have a 2ft torque wrench and it was very helpful for both removing and installing new ones.

When I put the new LCA, the bolt hole was not aligned, so I jacked the frame as someone suggested. When I was removing the old LCA on the other side, bolt wouldn’t come out, lifting frame on that side didn’t help, so I lifted the other side (already installed longer LCA on the side) and that moved it to loosen the bolts. As for installing the new longer LCA, I had to switch the jack to the installing side again to align the hole.

Torquing bolts was the hardest part. Front bolts were easier, because they were reachable from front and lifted more. Rear ones were torqued using a floor jack again.

Quick drive with new longer LCA felt more solid and straight (city drive only), and it made somewhat clear that slight wandering my Jeep has is not fixable with aftermarket adjustable LCAs. I have plenty of time left with warranty, so I will wait a little more to see how the new Steel Steering Box works and how dealers handle claims.

After 3 hours of muscle workout, I am very happy with the result. If I have to do this again, I would invest some money into power tools, or rental of them. Thanks again everyone who contributed to this and other threads.

Your experience sounds like mine although I didn't have as much issue aligning the bolt holes - got lucky there. Torqueing those was a pain and I also used a floor jack. An impact wrench helped with removing the bolts - although one still required a breaker bar to bust loose. Also some PB blaster put on the day before. But power tools don't help at all with re-torqueing the bolts - just good old fashioned leverage and muscle.
Looking back I wonder whether it's OK to re-use those bolts - or they're "stretch" bolts and shouldn't be re-used. Anyone know if it matters?

 

[limeade]

Your experience sounds like mine although I didn't have as much issue aligning the bolt holes - got lucky there. Torqueing those was a pain and I also used a floor jack. An impact wrench helped with removing the bolts - although one still required a breaker bar to bust loose. Also some PB blaster put on the day before. But power tools don't help at all with re-torqueing the bolts - just good old fashioned leverage and muscle.
Looking back I wonder whether it's OK to re-use those bolts - or they're "stretch" bolts and shouldn't be re-used. Anyone know if it matters?

Perfectly fine to re-use

 

[DavidArmen]

So interesting thing here, I have a 2020 2 door Rubicon.

My LCA part numbers are 68250242AB but I just measured my caster and seem to be at 6 degrees.

I'm having some vibration at 60-65mph and I'm thinking it's coming from the front-end so I was thinking maybe too little caster but that doesn't seem to be the case.

Same here... After reading this thread, I went to my 3 week old 2021 JLUR to check the caster and the LCA part number.

Measuring at one of the two big holes on the sides of the front differential on a level, zero degree surface, I got an exact 90 degree reading using the digital iPhone Measure app. From what I’ve read on this thread, this means I have a ~6 degree caster, correct?

Here’s the funny part, my front LCAs still have the old 68250242AB part number. Here’s a photo I just took where you can clearly see the last few digits:

I measured three times and always ensured my measurement was from a level, zero degree surface. Very curious situation indeed. I’d love to find out what’s going on with this and how my Rubicon can have 6 degree caster using the old lower control arms.

 

[blnewt]

Same here... After reading this thread, I went to my 3 week old 2021 JLUR to check the caster and the LCA part number.

Measuring at one of the two big holes on the sides of the front differential on a level, zero degree surface, I got an exact 90 degree reading using the digital iPhone Measure app. From what I’ve read on this thread, this means I have a ~6 degree caster, correct?

Here’s the funny part, my front LCAs still have the old 68250242AB part number. Here’s a photo I just took where you can clearly see the last few digits:

I measured three times and always ensured my measurement was from a level, zero degree surface. Very curious situation indeed. I’d love to find out what’s going on with this and how my Rubicon can have 6 degree caster using the old lower control arms.

It's possible they've changed something in the 2021s to get that caster up, maybe a slight difference in the LCA mounts perhaps???
They know low caster w/ Rubicons has been an issue and rather than giving them the proper LCA length maybe they've altered the mounts a bit to accommodate the old arms that apply to all JLs???

Otherwise maybe they might have to have a control arm recall for all pre 2021 Rubis???

 

[DavidArmen]

It's possible they've changed something in the 2021s to get that caster up, maybe a slight difference in the LCA mounts perhaps???
They know low caster w/ Rubicons has been an issue and rather than giving them the proper LCA length maybe they've altered the mounts a bit to accommodate the old arms that apply to all JLs???

Otherwise maybe they might have to have a control arm recall for all pre 2021 Rubis???

I’m really not sure what or how they achieved this but I’d love to take more photos of certain parts for anyone who is curious. I was shocked to see a perfect 90 degree reading from one of the flat holes on the sides of the diff cover (I used the hole closer to the driver side).

I first thought they are using shorter upper control arms to bring caster back to 6ish degrees but I don’t think that’s very logical considering they wouldn’t even use currently extant longer arms they already make for their lift kits...

 

[blnewt]

I’m really not sure what or how they achieved this but I’d love to take more photos of certain parts for anyone who is curious. I was shocked to see a perfect 90 degree reading from one of the flat holes on the sides of the diff cover (I used the hole closer to the driver side).

I first thought they are using shorter upper control arms to bring caster back to 6ish degrees but I don’t think that’s very logical considering they wouldn’t even use currently extant longer arms they already make for their lift kits...

It's surely possible they could sneak a shorter UCA into the Rubi, would be interesting to jot the UCA part # down and see if it matches previous year Rubis

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