Why is there jam nuts on the control arms?

rubicube

TJ Enthusiast
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Jun 6, 2019
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payson az
would.nt it be better if they rotated for flex they can't come unscrewed right.....with new ones there strong an fine threads...
 
What kind of joints or bushings are on the ends of your control arms?
 
would.nt it be better if they rotated for flex they can't come unscrewed right.....with new ones there strong an fine threads...
They don't rotate there enough to give added flex. If they did the old 1st generation control arms from Teraflex, which were also threaded there, wouldn't have earned such a terrible reputation for tearing their control mounts off from where they were welded to the frame or axle. Their problem was the shitty stiff bushings at both ends that didn't flex worth a crap.

TeraArms.jpg
 
They don't rotate there enough to give added flex. If they did the old 1st generation control arms from Teraflex, which were also threaded there, wouldn't have earned such a terrible reputation for tearing their control mounts off from where they were welded to the frame or axle. Their problem was the shitty stiff bushings at both ends that didn't flex worth a crap.

View attachment 371618

ya I see that on those I have a buddy with those on his tj but mine are the newer style so wouldn't a lil rotation in the middle be good.mine have the imitation JJ joint on the axle end...even with the jam nut they won't to rotate.
 
ya I see that on those I have a buddy with those on his tj but mine are the newer style so wouldn't a lil rotation in the middle be good.mine have the imitation JJ joint on the axle end...even with the jam nut they won't to rotate.
Nope, not even a little rotation is good there. Let whatever flex joint Tera installed do it's job.
 
there teraflex I hate them when I have 2000 to blow I'll change but why the jam nuts, they loosen now an then any way.

They don't twist because the threads seize. Even if they did twist reliably without eventually ruining the threads, the track bars still push the arms side to side with the axle. The bushing or joint needs to have enough misalignment to accommodate that movement, which the Teraflex arms do not. That is why they have the reputation of tearing off the control arm mounts. They were never a good design.
 
would.nt it be better if they rotated for flex they can't come unscrewed right.....with new ones there strong an fine threads...

There have been a couple of brands that have tried that, and they work for a while, but if you don't maintain the grease on the threads they eventually wear themselves out and will fail at the threaded portion.

Here's a video I made a few years ago:

 
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Those particular arms would still have a shitty poorly functioning design even if they were greased 3X a day.

ok so I get the front set of core t4 do I jus make en all the same length that the old ones area have no vibes.but I seen people talk about cycle the suspension.i have a 3" gonna wait on the rear.and I got the diff side bushings to press in.
 
ok so I get the front set of core t4 do I jus make en all the same length that the old ones area have no vibes.but I seen people talk about cycle the suspension.i have a 3" gonna wait on the rear.and I got the diff side bushings to press in.

man jus ordered the core 4x4 tier 4 front arms an they gave me a 15%off code without even asking....all rocjok j joints,,,
 
ok so I get the front set of core t4 do I jus make en all the same length that the old ones area have no vibes.but I seen people talk about cycle the suspension.i have a 3" gonna wait on the rear.and I got the diff side bushings to press in.

The easiest way is to remove 1 arm at a time, adjust the new arm to the same length and install it, then repeat with the rest. Once all are installed, I adjust them to get my pinion angle how I want it. I'm not sure if you already have a 3" lift, or if you're going to install a 3 lift. If you're already lifted and are just switching out the arms and everything it already adjusted correctly, then just swap the arms 1 at a time.

As far as diff side bushings, check out the Currie axle housing Johnny Joint kit. It's not very expensive, will practically last forever, and will work the best with the control arms you just bought. The passenger side does require welding, but that's usually not to expensive either usually.
 
The easiest way is to remove 1 arm at a time, adjust the new arm to the same length and install it, then repeat with the rest. Once all are installed, I adjust them to get my pinion angle how I want it. I'm not sure if you already have a 3" lift, or if you're going to install a 3 lift. If you're already lifted and are just switching out the arms and everything it already adjusted correctly, then just swap the arms 1 at a time.

As far as diff side bushings, check out the Currie axle housing Johnny Joint kit. It's not very expensive, will practically last forever, and will work the best with the control arms you just bought. The passenger side does require welding, but that's usually not to expensive either usually.

ya I already have a 3"lift just replacing the woreout treaflex crap and about a month ago put on new goodyear wranglers an the tire shop said toe perfect but the caster off an they could'nt ad just it, but the top arms are stocks. so now I'll have all 4 front core t4....jus have to fig.out how to adjust the caster...then sometime after xmas I'll do the rear.i live 100 mike from the big city so it's hard to find shop that knows anything...jus got a bigO haha
 
The easiest way is to remove 1 arm at a time, adjust the new arm to the same length and install it, then repeat with the rest. Once all are installed, I adjust them to get my pinion angle how I want it. I'm not sure if you already have a 3" lift, or if you're going to install a 3 lift. If you're already lifted and are just switching out the arms and everything it already adjusted correctly, then just swap the arms 1 at a time.

As far as diff side bushings, check out the Currie axle housing Johnny Joint kit. It's not very expensive, will practically last forever, and will work the best with the control arms you just bought. The passenger side does require welding, but that's usually not to expensive either usually.

thnx i will do 1 at a time an make em the same length cause it drives nice now, jus feels wobbly..
 
ya I already have a 3"lift just replacing the woreout treaflex crap and about a month ago put on new goodyear wranglers an the tire shop said toe perfect but the caster off an they could'nt ad just it, but the top arms are stocks. so now I'll have all 4 front core t4....jus have to fig.out how to adjust the caster...then sometime after xmas I'll do the rear.i live 100 mike from the big city so it's hard to find shop that knows anything...jus got a bigO haha
Once you have them all installed, to adjust your caster you lengthen or shorten the arms together in pairs to rotate the pinion up or down. I usually adjust so my pinion is pointing directly at my CV joint so the driveshaft and pinion are inline with each other. I don't worry about my caster angle so much as the factory adjustment is wrong for a lifted Jeep anyways. The larger the tire the less caster you require.
 
Once you have them all installed, to adjust your caster you lengthen or shorten the arms together in pairs to rotate the pinion up or down. I usually adjust so my pinion is pointing directly at my CV joint so the driveshaft and pinion are inline with each other. I don't worry about my caster angle so much as the factory adjustment is wrong for a lifted Jeep anyways. The larger the tire the less caster you require.

should I go to ACE an get a mag.angle finder,,tires are 265/70/17 goodyear wrangler workhorse
 
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my 99 TJ had the old teraflex arms with no jam nuts. The threads had worn out and someone welded them solid instead of replacing the arms.
 
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Once you have them all installed, to adjust your caster you lengthen or shorten the arms together in pairs to rotate the pinion up or down. I usually adjust so my pinion is pointing directly at my CV joint so the driveshaft and pinion are inline with each other. I don't worry about my caster angle so much as the factory adjustment is wrong for a lifted Jeep anyways. The larger the tire the less caster you require.

damn I ordered the core t4 arms yesterday and they shipped today...........fed x says day after tomorrow .
 
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