Can someone explain this to me?

[Prerunin554]

I've noticed that most lift kits for the twin I-beam rangers have moved to using a J arm set up. What benefits/downfalls does this have over the standard I beams/Radius arms set up? The only difference i can really tell is the joint where the beam and radius arm meet would/could be stronger. Is this a weak point in this type of suspension? Sorry for my ignorance, but i am used to building trucks with A arms, its my first ranger.

Thanks in advance for everyones input-

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[Steven_Tolbert]

Well some people perfer the J-arm because its is stronger and you have less moving parts

[philofab]

I've never done it but the radius arm/beam bolt can shear.

[partybarge_pilot]

J-arm's have a lot of advantages.

1, lighter
2, less parts
3, stronger
4, less work to make
5, less liability for someone F'ing up the install

I have seen a lot of radius arms fail where they attach to the beam due to the mounting tabs cracking. This isn't a problem if it's all one piece.

[151fab]

I would thing the "J" arm would fatigue due to the chassis flex between the mounting points. Apparently I'm wrong, but just a thought. Also, it seems that it would be harder to make a J arm because the bolt between the rad and beam would compensate for inaccuracies in the chassis or suspension arms, the j arm doesn't have that attribute.

[philofab]

If you build you cage right you shouldn't have chassis flex. A stock frame shouldn't flex that much between those points even without a cage.

You are correct though... it's not as forgiving as a two piece setup.

[partybarge_pilot]

I would thing the "J" arm would fatigue due to the chassis flex between the mounting points. Apparently I'm wrong, but just a thought.

Not an issue.

Also, it seems that it would be harder to make a J arm because the bolt between the rad and beam would compensate for inaccuracies in the chassis or suspension arms, the j arm doesn't have that attribute.

Also not an issue. What little adjustment that is needed to compensate for variances in the frames is more than handled by the hiems.

[Giant Geoff]

I have crashed both styles into a square ditch and the radius arm bends the same. Repairing/replacing the J beam style is much more difficult because all the cutting and grinding it takes to remove the radius arm, the 2 pc. style is much easier because it unbolts in about 48 seconds.

I find the 2 pc. style easer to make and the J beams has no adjustment at all, you move the hiem a half turn and it will not line up any more with the hole.

I have not done the J beam style in 5 years and recently crashed into a ditch 3 months ago. I’m so glade I have the 2 pc. and got my truck back to together in 5 hours instead of the 4 day repair like before.

[Steven_Tolbert]

but isn't your new prismatic beams a j arm

[Giant Geoff]

No, It's a 2 pc.