Extending stock radius arms vs new cage arms

[bronko69er]

That looks like it's be essentially the same thing (rremoving the bolt).

 

[DanWheeler]

I wonder if I could find a 1.75" square tube nut. The BC arms are 2x2 5/16ths.

ballistic has up to 1.5"

 

[bronko69er]

The only downfall of the WAH or the hinged arm is that all the axle torque is being restraind by 1 arm instead of both. I have no idea how close it pushes the other arm toward failure but it does increase the bending load due to torque by a factor of 2. The nice thing about the hinged arm is that you can always replace that bolt with a pin that you hammer out for wheeling and hammer back in for the road.

 

[chuck]

My radius arms will not work as a wristed arm because it would wear the clamping surfaces which would cause the head to rotate and screw up the caster.
As I see it there are 3 seperate forces at work on the housing.
1. The braking force tries to rotate the housing foreward that is stopped by the radius arms, 2. the acc. force that tries to rotate the housing foreward and is stopped by the radius arms and 3. the twisting force caused by articulation of the radius arms (one up and one down) that is stopped by the housing. Number 3 is relieved by both the WAH and the wristed arm.
With a wristed arm all of 1 and 2 forces are stopped by the drivers side radius arm. The braking force causes the right front to dive when the radius arm is unpinned because the force is not stopped by the right radius arm. The right front would raise if you could acc hard enough but doesn't seem to be a problem. The most force is braking force.
Because the WAH rotates inside the radius arms force 1. is stopped by both radius arms. Force 2 is stopped by only the drivers side radius arm.
Force 1 is applied by the wheels, force 2 is applied by the driveshaft.
I have used the WH track bar raise bracket with the WAH without problems but the one in the above picture would be in the way of the WAH but not by much, I will do some measureing tomorrow and try to figure out what is diff.

 

[Hal9000]

...Now you are looking at a rig or arms that already have the extensions. Remember, there were some extensions on the market before ours that did not thread on but simply welded with the weld being the only contact with the radius arm. The extensions may look similar but there is a huge difference. If you like, you can send me some pictures of the arms "close up of the extensions" and I can tell you if they are ours or not.
Thanks, Anthony.
Stone Crusher Steering...

Sorry, no photos yet, but I got those extended arms on Sunday. The seller didn't even know about Stone Crusher Steering, but told me he made the extensions himself using either .250 or .375 wall DOM tubing (he couldn't remember which, but said it was very thick). I don't like the looks of his welds (not enough material there... Looks like he used too small dia wire and only did one pass), so at the very least I'm going to re-weld the joint and then drill 2-3 holes so I can add rosette welds to the original threaded shaft. Not a perfect solution, but it should still dramatically increase the strength of the extension.

I'm also considering taking my own advice and cutting the extensions down, threading the ends, and adding a heim.....

 

[DanWheeler]

here's a sketch of what I was thinking about for the BC arms:

 

[DanWheeler]

the only problem here is that the arm will want to twist/rotate within the side plates because of the johnny joint but wont really be able to because the 2x2 tube is just as wide as the side plates. it will just end up spreading the plates apart which would be really bad.

I measured a stock bronco track bar bushing but it was 1.75" wide. Close. I might still be able to make something work.

There's also the possibility of leaving it as is and removing one bolt but thats pretty ghetto and would probably eventually oval out the hole.

 

[DanWheeler]

OK, i think i have something here. I know this seems like a lot of trouble when I could just make a wristed arm using an old radius arm but my goals are

- backwards compatibility, (in case it doesn't work)
- completely eliminating bind
- strength
- bolt on (as much as possible - less cutting and welding the better)

To completely eliminate bind it means I need heims at the frame. I haven't found a great way to attach heims to the stock arms using the existing frame mounts. I really want to leave the frame mounts as-is in case I dont like the way things turn out. Thats why the BCB arm's heim design is so great - you can always go back to stock.

I found some bushings on polyperformance that could be cut to a 2" width. I am thinking about cutting the last 1-2" off the BC arm's side plates to allow some rotational flex in the bushing (still not sure if thats even necessary) and then use a mount on top of the arm and a link w/ small heims to connect to one of the pre-existing shock mounting locations with a pin to lock it when on the street.

thoughts?

 

[DanWheeler]

the link that acts as a pin would swing back when on the trail kind of like a sway bar disconnect.

these are the bushings. Specifically the PPM-4304 cut down to 2" width:
http://www.polyperformance.com/shop/Poly-Performance-Bushing-Kits-p-16605.html

 

[DanWheeler]

one more thing to add. I would need to cut and bend the end of the 2" square tube so it could make contact with the cylindrical bushing housing on all 4 sides of the tube:

 

[Hal9000]

Here's an idea. Why not replace the sqare tube with round tube, and put the heim on the front end of the bar, between the side plates. You can still pin it at the rear bolt hole, and I think you'll get rid of all the problems you're fighting with your design. Plus all you have to do is fab up the new arm and bolt it in. If you don't like it, just bolt the stock square tube back in and you're back to square one.

 

[DanWheeler]

Here's an idea. Why not replace the sqare tube with round tube, and put the heim on the front end of the bar, between the side plates. You can still pin it at the rear bolt hole, and I think you'll get rid of all the problems you're fighting with your design. Plus all you have to do is fab up the new arm and bolt it in. If you don't like it, just bolt the stock square tube back in and you're back to square one.

Its a great idea but I couldn't figure out a way to connect the tube with a heim to the stock radius arm mounts. I'd really prefer to leave those intact.

I dont think I could attach a heim on the round tube the way Chuck/BCB does with his square tube radius arms.

I'm all ears for ideas - it would be an easier way to go.

 

[welndmn]

So in Summary...
You want to take a 600$ part and re engineer it into something it never was?
With the amount of time and money spent, you could run a link suspension.

 

[Hal9000]

Its a great idea but I couldn't figure out a way to connect the tube with a heim to the stock radius arm mounts. I'd really prefer to leave those intact.

I dont think I could attach a heim on the round tube the way Chuck/BCB does with his square tube radius arms.

I'm all ears for ideas - it would be an easier way to go.

Are you talking about not being able to attach a heim to the frame-end radius arm mounts? If you have a heim at the axle end, you should be able to keep the stock mounts at the frame. You should only need the heim at one end.

For attaching to the round tube, couldn't you just use a threaded insert the same way you would for any other link suspension? You'd probably need spacers on either side of the heim to fill any gap between the plates. But since you need space for the heim to articulate anyway, that shouldn't be much of a problem.

Maybe I'm just missing a piece of the puzzle or misinterpreting what you want to do, but I think both these problems are easily overcome.

 

[Hal9000]

So in Summary...
You want to take a 600$ part and re engineer it into something it never was?
With the amount of time and money spent, you could run a link suspension.

Isn't that half the fun of DIY projects

FWIW, what I'm envisioning wouldn't cost much. Just a single piece of tubing, heim/threaded insert/spacers for the axle end, and a threaded bolt for the frame end (well, that and some fabrication and drilling). And it wouldn't ruin the original part so it could be returned to stock in a matter of a few minutes.

 

[DanWheeler]

So in Summary...
You want to take a 600$ part and re engineer it into something it never was?
With the amount of time and money spent, you could run a link suspension.

It may seem complicated but what I'm proposing would require a minimum of cutting and welding (and math) whereas a full link suspension is a major commitment.

Hal9000, I think you are right - I will use a tube instead of the provided square tube. I'll put that aside for later use in case whatever I build doesn't work.

I'd like to use a 2" wide johnny joint on the axle end and I'll re-utilize the heim joint that comes with the BCB kit on the frame end. I'll buy a universal frame mount and some DOM from Ballistic fab.

Are the stock radius arm frame mounts just bolted on? or are they also welded?

 

[bronko69er]

Are the stock radius arm frame mounts just bolted on? or are they also welded?

Both welded and bolted.

 

[Hal9000]

So I just looked at the photos on the BC website for their radius arms. Now I understand how they're mounting the heim joint. It's not totally necessary in my opinion (at least not for the articulated arm you're thinking about, but if the mounts are already on your truck, then go with it. I can't see how it would affect the design at all.

I thought for a second that the top heim might alleviate the need for the heim/Johnny joint at the axle, but after doing some mental exercises about how the arm and axle would interact, I think you'll still need one at the axle as well.

 

[Hal9000]

Here's another renegade idea that will let you keep the square tubing if you want to keep things looking the same from side to side:

Retain the heim joint at the frame mount, but at the front bolt at the axle end, add a urethane bushing. Then cut the tube just behind the side plates, add a (fine) threaded insert to one side, and a matching threaded rod to the other. Thread the two halves together almost until the square tubing touches. When you pin the rod it will work/act exactly like the stock radius arm. When you unpin it, the bushing will handle the up-down articulation, and the threaded section will handle the roation. Since you're only dealing with maybe 1/8 of a turn, the overall length of the arm won't change by more than a mm, which should be completely acceptable.

As long as you have a long enough threaded insert to prevent any wobble, and use some decent waterproof grease on the threads, the joint should last a lifetime. Since you have room to play with on the inside of the square tubing, I'd probably use as large of a threaded rod (or maybe an externally threaded piece of DOM?) as I could find. Say 1" or so. You're not going to bend that unless you're getting really crazy.

 

[DanWheeler]

Here's another renegade idea that will let you keep the square tubing if you want to keep things looking the same from side to side:

Retain the heim joint at the frame mount, but at the front bolt at the axle end, add a urethane bushing. Then cut the tube just behind the side plates, add a (fine) threaded insert to one side, and a matching threaded rod to the other. Thread the two halves together almost until the square tubing touches. When you pin the rod it will work/act exactly like the stock radius arm. When you unpin it, the bushing will handle the up-down articulation, and the threaded section will handle the roation. Since you're only dealing with maybe 1/8 of a turn, the overall length of the arm won't change by more than a mm, which should be completely acceptable.

As long as you have a long enough threaded insert to prevent any wobble, and use some decent waterproof grease on the threads, the joint should last a lifetime. Since you have room to play with on the inside of the square tubing, I'd probably use as large of a threaded rod (or maybe an externally threaded piece of DOM?) as I could find. Say 1" or so. You're not going to bend that unless you're getting really crazy.

wow, that could be a really good idea. DO you know where you could get threaded inserts and rods for 2x2 square tubing?