radius arm build tech

[br0nc0xrapt0r]

Are you using coils? I see in some pics coils and C/O in others.

My three link looks similar but I need to figure out what to do with the coil cups. I'd like to see more of how those coil cups are attached to the mounts.

 

[u10072]

well I would disagree with the non use of a rod end at every connection. There are too many JK and TJ suspensions that say otherwise. If there is bind, then the geometry is simply wrong-- its all just a simple practical geometry issue.

 

[dao1980]

In my past experiences, I have come to understand that the geometry and associated loads of a radius arm setup are different than with a 5link setup as seen in XJ's ZJ's TJ's and even the RAM trucks.

The 5link has separate upper and lower links that (while moved in opposite arcs) exert much less "twisting" force on the axle housing itself, than with a single span radius arm or even a combined "Y" radius arm.

Think about the BC wah, and what the idea is attempting to relieve from the axle housing.

Now, I'm not commenting here on what the housing itself can deal with "twist" wise, or if you should or shouldn't use whatever joint wherever..
I'm just sharing my .625 cents worth on the fundamental differences between Bronco/Ford radius, and Jeepy/Cherokee 5link.

 

[dao1980]

Though, that all has me thinking, what kind of jelly-doughnut of a ride would you have if you used a 5link WITH a wah?... haha, would she wander all over the road? Or just feel nice and flexy on an "as needed" basis.

 

[73bronco]

well I would disagree with the non use of a rod end at every connection. There are too many JK and TJ suspensions that say otherwise. If there is bind, then the geometry is simply wrong-- its all just a simple practical geometry issue.

Now you threw out a different link set up than this is. I was simply referring to THIS set up. In this set up(upper link and lower link 100% vertical at the axle end with a single plane of angle when articulating) there will be bind based on design. The TJ and JK s put the upper link at a fairly extreme angle at the axle connection points. That set up allows the links to rotate with the angle sweep. If you've ever watched a TJ or JK with the long arm set up you're referring to you'll see how that set up works and how it's different from this set up. It is simple geometry, of which this set up is off and binds, therefore, needs the bushings to flex absorbing the bind.

 

[u10072]

My only point is that if you are going to use all rod ends and a Y-style radius arm-- if having the rod ends in all the same plane doesn't articulate then move that short part of the Y arm inboard similar to a JK/TJ design. As far as a WAH goes-- I would personally wonder how many WAH housings are going to be used in the KOH race this weekend? I bet none is the answer-- but I bet there are plenty with radius arm designs and have a trac/panhard bar. Those are the designs that should drive your design IMO due to being so very similar to that on an EB.

 

[Rymadd]

Been listening in on this and really want to do a set of radius arms in the future, is what you guys are saying to do is move the upper axle tube mounts closer together then the lower axle tube mounts? Basically twisting the Y arms inward?

GOT ANY PICTURES?

 

[Desert Thrasher]

Chirper this is what they are talking about. Jeep Tj long arms.

 

[mavereq]

Agreed. That is a great place for a rod end. Every other joint in this type of suspension set up should be a bushing; at least at all the axle side connections. Otherwise there will be a ton of bind on the axle housing.

I was referring to the axle end. I agree the frame end is a good place for a heim or uniball.

 

[Rymadd]

Chirper this is what they are talking about. Jeep Tj long arms.

So moving the upper links closer together on the axle housing decreases how soon they start to bind?

 

[treihesse]

Yes the upper arms moved in does relive some amount of bind. Radius arms will always have some bind no matter what. The engineering behind the tj arms is also based on more frame width and wheel base. Its hard to do it on a eb axle. Full width maybe. Better off doing a 3 link. I don't like 3 links due to the safety. If one link fails it CAN be more catastrophic

 

[treihesse]

It also really helps to kick your frame brackets in alot. Look at steves orange bronco build he built a x member and angled the bracket towards the axle bracket. When I have spoke to a few people they said this takes away alot of bind and puts the two brackets on the same plane

 

[mavereq]

if you decide to run bushings at the axle, you can swap them out easily:

http://www.ballisticfabrication.com/Ballistic-Forged-Poly-Bushing-263_p_1646.html

 

[Rymadd]

I know there will always be bind with radius arms, people with 3 link like to throw that out every other sentence, that's why I said reduces how soon it stops your axle from flexing. However since I don't do a lot of nasty rock crawling where you need a lot of flex, I don't see a reason to shy away from it. Plus radius arms seem safer for the highway which I like to do 80mph down. So move upper links in on the axle tube, move frame mounts in farther inward. Any math/ geometry to go off of or just make it work? I don't know who steves orange bronco is...

 

[Rymadd]

if you decide to run bushings at the axle, you can swap them out easily:

http://www.ballisticfabrication.com/Ballistic-Forged-Poly-Bushing-263_p_1646.html

Those look sweet, just wondering if somebody made a threaded bushing!

 

[treihesse]

I already ordered those on Monday

 

[broncojo]

Hope you get them in a timely manner, I've ordered from ballistics a few times and they seem to mess up something each time. Great products though other than the crappy service, however they always did resolve the problem.

 

[mavereq]

I normally call ballistic about two days after i place the order

 

[mavereq]

I know there will always be bind with radius arms, people with 3 link like to throw that out every other sentence, that's why I said reduces how soon it stops your axle from flexing. However since I don't do a lot of nasty rock crawling where you need a lot of flex, I don't see a reason to shy away from it. Plus radius arms seem safer for the highway which I like to do 80mph down. So move upper links in on the axle tube, move frame mounts in farther inward. Any math/ geometry to go off of or just make it work? I don't know who steves orange bronco is...

I totally agree and if I weren't building a rig to take out and thrash on the trails, I probably would have went with radius arms. I also would use bushings to absorb road vibrations. Using radius arms with bushings at the axle joints gives your vehicle a lot of stability. The suspension has a sway bar effect built in.

Another reason I shied away from the radius arms is because of the instant center the suspension has. It can cause your front end to unload and lift the nose. That's not something I want when I'm trying to climb.

Whatever suspension you go with, there's a good chance you're going to make changes and adjustments in the future. That's the fun of building these rigs; they're never done. You can try something and if you don't like it, break out the plasma and welder. The good thing about this forum is that you can learn from other people's builds.

 

[jmeyer1971]

I totally agree and if I weren't building a rig to take out and thrash on the trails, I probably would have went with radius arms. I also would use bushings to absorb road vibrations. Using radius arms with bushings at the axle joints gives your vehicle a lot of stability. The suspension has a sway bar effect built in.

Another reason I shied away from the radius arms is because of the instant center the suspension has. It can cause your front end to unload and lift the nose. That's not something I want when I'm trying to climb.

Whatever suspension you go with, there's a good chance you're going to make changes and adjustments in the future. That's the fun of building these rigs; they're never done. You can try something and if you don't like it, break out the plasma and welder. The good thing about this forum is that you can learn from other people's builds.

A M E N...versatility is what makes a bronco great