Mopar LCA swap

[stumblinhorse]

I'm using a Joe's racing tire gauge. It's much more accurate than the slime one I used to use.

A wise man once said “a person with a tire pressure gauge always knows what tire pressure they have in their tires. A person with 2 tire pressure gauges never know what tire pressure they have in their tires”

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[Jtphoto]

The other think you can see in the picture is that the stock LCA (top) has the hard rubber bushings, and the .25" longer Mopar LCA (bottom) doesn't appear to have any bushing. You can see in this OP photo the absence of a bushing. I have these longer Mopar LCAs so have noticed this in person, but the photo shows it too.

Is there any need for a rubber bushing for the longer Mopar LCAs? Is it OK to install the longer Mopar LCAs with metal to metal contact between them and the LCA mount flanges on the frame and axle? Or will the result in metal to metal grinding?

Lots of aftermarket adjustable LCAs seem to have no bushing either, and I understand that rubber bushings there can bind and reduce articulation at the extremes. What is the best practice for avoiding metal to metal grinding and the corrosion that would result?

That lift LCA also has a rubber bushing, zoom in and gave a better look. It’s just a different design than the original LCA. All control arms have some sort of bushing or flex joint.

 

[OrneryBear]

I was able to knock this out on my otherwise stock (suspension wise) JLUR this Sunday. Drives great! Took maybe an hour at most with the jeep on all 4 tires on the ground, taking my sweet time and drinking a couple beers. I still need to adjust the drag link to re center the steering wheel, but whatever, that will take a few minutes tonight. I definitely was not able to get the range of motion easily to use my torque wrench, so I just hit them with the impact and I'll put it up on ramps or jack-stands this weekend and re torque.

 

[nU7OuxIx]

I was able to knock this out on my otherwise stock (suspension wise) JLUR this Sunday. Drives great! Took maybe an hour at most with the jeep on all 4 tires on the ground, taking my sweet time and drinking a couple beers. I still need to adjust the drag link to re center the steering wheel, but whatever, that will take a few minutes tonight. I definitely was not able to get the range of motion easily to use my torque wrench, so I just hit them with the impact and I'll put it up on ramps or jack-stands this weekend and re torque.

How much did it uncenter your steering wheel? I figured that it wouldn't need an alignment afterwards, but I guess if you're moving the entire axle up a quarter inch, that drag link may need to get adjusted.

 

[Jtphoto]

How much did it uncenter your steering wheel? I figured that it wouldn't need an alignment afterwards, but I guess if you're moving the entire axle up a quarter inch, that drag link may need to get adjusted.

Actually you are not moving/lifting the axle up at all.. All you’re doing is slightly twisting it which will only change your caster/pinion angle, nothing more. You draglink /steering wheel will not change. The steering wheel / draglink only changes when you actually lift the Jeep with spacers or springs.

 

[STW]

That lift LCA also has a rubber bushing, zoom in and gave a better look. It’s just a different design than the original LCA. All control arms have some sort of bushing or flex joint.

so the bushing it has is surrounding that center hole where the mounting bolts go? I read elsewhere on this thread that the mopar lift LCA has a higher quality bushing than the stock one.

If so, then what I was incorrectly calling the bushing is that rubber side on the end of the stock LCA that puts a layer of rubber vertically in between the sides for the LCA mount hole and the ears of the LCA mount. That's where I'm concerned about grinding and corrosion--the metal edges of the mopar lift LCA against the metal ears of the LCA mount on the frame and axle.

Or I suppose any aftermarket LCA that is just metal on the ends like that. No sure I should be worried about it since most aftermarket LCAs are set up like the Mopar lift one. And if there was any grinding going on between edge of LCA and the ears of the LCA mount, then it's hard to see that rubber layer on the stock LCA lasting very long at all.

 

[OrneryBear]

How much did it uncenter your steering wheel? I figured that it wouldn't need an alignment afterwards, but I guess if you're moving the entire axle up a quarter inch, that drag link may need to get adjusted.

At most 15 degrees?
You totally don't need an alignment after changing LCAs because of the geometry of a solid axle, the wheels won't change their toe in relation to one another. Since the two lcas are a fixed length, theoretically the axle should still be parallel to where it was before as well. The only reason the steering wheel moves is because the drag link stays the same length and one pivot (on the right knuckle) moved linearly rearward as the bottom of the axle rotates forward, thus moving the pitman arm over. That's if I'm keeping all my geometry explanation straight in my head. Totally sorry for the explanation if you already know how all this geometry works, I'm mostly talkin out loud for my own amusement. As a prototype engineer I'm always working through what I'm doing double/triple checking myself.

All that crap said, it only took a couple minutes to get the drag link adjusted. Did a couple rounds of adjusting and test driving to call it good before torqueing it down. The hardest part is where we live is all rural with really crowned/peaked roads, so even a perfectly aligned steering wheel is never centered. I just used the offroad pages to at least know when I was at "0°" roll haha.

 

[jav_eee]

so the bushing it has is surrounding that center hole where the mounting bolts go? I read elsewhere on this thread that the mopar lift LCA has a higher quality bushing than the stock one.

If so, then what I was incorrectly calling the bushing is that rubber side on the end of the stock LCA that puts a layer of rubber vertically in between the sides for the LCA mount hole and the ears of the LCA mount. That's where I'm concerned about grinding and corrosion--the metal edges of the LCA against the metal ears of the LCA mount on the frame and axle.

the short LCAs don’t have rubber between metal. This is them:

 

[STW]

the short LCAs don’t have rubber between metal. This is them:

ah you're right. No wonder that extra rubber there wasn't torn up on my stock ones when I replaced them with the mopar lift LCAs.

 

[Jtphoto]

At most 15 degrees?
You totally don't need an alignment after changing LCAs because of the geometry of a solid axle, the wheels won't change their toe in relation to one another. Since the two lcas are a fixed length, theoretically the axle should still be parallel to where it was before as well. The only reason the steering wheel moves is because the drag link stays the same length and one pivot (on the right knuckle) moved linearly rearward as the bottom of the axle rotates forward, thus moving the pitman arm over. That's if I'm keeping all my geometry explanation straight in my head. Totally sorry for the explanation if you already know how all this geometry works, I'm mostly talkin out loud for my own amusement. As a prototype engineer I'm always working through what I'm doing double/triple checking myself.

All that crap said, it only took a couple minutes to get the drag link adjusted. Did a couple rounds of adjusting and test driving to call it good before torqueing it down. The hardest part is where we live is all rural with really crowned/peaked roads, so even a perfectly aligned steering wheel is never centered. I just used the offroad pages to at least know when I was at "0°" roll haha.

I am surprised. Did you also change springs or add spacers? Changing the LCA should not have affected your steering wheel center at all. I’ve changed plenty of LCAs and installed Geometry Correction Brackets and have never had to touch the steering wheel center.

 

[OrneryBear]

I am surprised. Did you also change springs or add spacers? Changing the LCA should not have affected your steering wheel center at all. I’ve changed plenty of LCAs and installed Geometry Correction Brackets and have never had to touch the steering wheel center.

Nope, just mopar LCAs. Like my explanation above, I've been thinking through why the steering could have moved, and that's the only explanation I can come up with. Only other explanations I can come up with is that the jeep was not perfectly level and in gravel and/or I turned the wheels slightly to get the impact in to torque the front bolts on the lcas down, but in my mind there isn't enough tolerance between the bolt and the bushing sleeves to create that sort of change. Only explanation I think is valid, is just a slight change in geometry.

I'm totally open to your (or anyone elses) thoughts. Jeep drives great, so I don't think I screwed anything up haha

 

[Jtphoto]

Nope, just mopar LCAs. Like my explanation above, I've been thinking through why the steering could have moved, and that's the only explanation I can come up with. Only other explanations I can come up with is that the jeep was not perfectly level and in gravel and/or I turned the wheels slightly to get the impact in to torque the front bolts on the lcas down, but in my mind there isn't enough tolerance between the bolt and the bushing sleeves to create that sort of change. Only explanation I think is valid, is just a slight change in geometry.

I'm totally open to your (or anyone elses) thoughts. Jeep drives great, so I don't think I screwed anything up haha

As long as it drives great that is all that matters. Enjoy!!!! Could have been out a bit from factory or some spring sag. You corrected it, that’s all that matters.

 

[ArmyRN]

I ordered my 2023 Willys JLU XR 2.0T back in December. It arrived on 10 March. Even before it arrived, I had already ordered the Mopar LCAs based on what I'd been reading on this forum. So far I've got 400-something miles on the Jeep. Today I installed the Mopar LCAs.

Not too difficult or technical. The bolts were a PIA to remove (not unexpected). I had the Jeep's axle up on jack stands to give me a couple extra inches to work with/room to swing socket wrenches. Kept the tires on (in hindsight it might have been a little easier maneuvering around under the Jeep had I pulled the tires). My electric impact wrench wouldn't budge those big LCA bolts, so picture me crawled under the Jeep with a 1/2" drive ratchet with a cheater pipe, holding on to the crossmember with my hands and pushing on the cheater pipe with my leg to bust it loose. Repeat until I could turn the ratchet itself by hand. Now multiply that times four bolts. Once I got all four nuts off, then I went about replacing the LCAs.

I did have to remove the skidplate protecting the FAD so the socket (and extension) would fit. Helpful hint: Pull the rear bolts out first; if there's any binding, they're easier to get to. Once the rears are out, the front ones will pop right out. Then put the front bolts in first with the new LCAs. I thought I might have to do a little moving of the axle to get the second set of bolts (rears) lined-up and in, but no problem.

I cranked them all down with my electric impact wrench. Then went to torque them.

My torque wrench only goes to 150lbs, so after it clicked (again, using leg power but no cheater bar - didn't need it) I went another 90-degrees (maybe a little more) and called it good.

Then I took it for a test drive, to include the highway. Not a huge difference (I thought it drove pretty nice as it was), but it did seem a little more planted (if that makes sense). Drove just a little bit nicer. I'm pleased. I'm planning on driving it from WA to FL (and back) this fall.

 

[OrneryBear]

I ordered my 2023 Willys JLU XR 2.0T back in December. It arrived on 10 March. Even before it arrived, I had already ordered the Mopar LCAs based on what I'd been reading on this forum. So far I've got 400-something miles on the Jeep. Today I installed the Mopar LCAs.

Not too difficult or technical. The bolts were a PIA to remove (not unexpected). I had the Jeep's axle up on jack stands to give me a couple extra inches to work with/room to swing socket wrenches. Kept the tires on (in hindsight it might have been a little easier maneuvering around under the Jeep had I pulled the tires). My electric impact wrench wouldn't budge those big LCA bolts, so picture me crawled under the Jeep with a 1/2" drive ratchet with a cheater pipe, holding on to the crossmember with my hands and pushing on the cheater pipe with my leg to bust it loose. Repeat until I could turn the ratchet itself by hand. Now multiply that times four bolts. Once I got all four nuts off, then I went about replacing the LCAs.

I did have to remove the skidplate protecting the FAD so the socket (and extension) would fit. Helpful hint: Pull the rear bolts out first; if there's any binding, they're easier to get to. Once the rears are out, the front ones will pop right out. Then put the front bolts in first with the new LCAs. I thought I might have to do a little moving of the axle to get the second set of bolts (rears) lined-up and in, but no problem.

I cranked them all down with my electric impact wrench. Then went to torque them.

My torque wrench only goes to 150lbs, so after it clicked (again, using leg power but no cheater bar - didn't need it) I went another 90-degrees (maybe a little more) and called it good.

Then I took it for a test drive, to include the highway. Not a huge difference (I thought it drove pretty nice as it was), but it did seem a little more planted (if that makes sense). Drove just a little bit nicer. I'm pleased. I'm planning on driving it from WA to FL (and back) this fall.

Dont feel bad on the impact, I think Jeep is over-torqueing them from the factory. my milwaukee impact is rated at 1400 ft/lbs of extraction force, and it took some major hammering to get them loose, and we only have 3500 miles on the jeep. I've had that same impact make light work of fasteners rated at 300-450 ft/lbs on my fords and hondas, so I'm suspicious of jeep's factory QA, big surprise haha

 

[dogslbr]

I know I"m beating a dead horse here, but Just put the slightly longer LCA on my new XR that I've had for about a week. VERY noticeable difference in the handling on the interstate. Much less "twitchy" over 70mph. It wasn't bad before but I knew it needed a little more caster and these did the trick. Without this thread I wouldn't have known such a thing existed short of going to a full on adjustable arm. Great mod for under $100.

Combined with the AEV/Northridge Steering stabilizer a huge improvement in overall handling of the jeep.

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