Trying to learn about wristed radius arms

[green50gt]

My setup is this. 75, 5.5 coils, D44 track lock, 3" body, 33" TSL's. It had 38s on it. Other than that, thats the way I bought it, so dont give me any flack.

I am trying to learn about wristed radius arms and whatnot. I will not be doing the wristed axle housing. thats that. I am hoping to see some pictures or get some explanations of the wristed radius arms. A couple of the pictures I have found as of yet have been some ghetto jobs. I am not looking for ghetto. I'd like a nice clean setup. To me, I would think when the axle drops, you would want the radius arm to turn essentially instead of basically breaking apart(hope that makes sense)

I have found people are adding like 6" or so to the rear of the radius arm, that doesnt seem too hard. Does that really help? I have also seen a couple wristed radius arm mounts, which that looks pretty cool, but I doubt it helps a whole lot. I have to move my radius arm mounts anyway, because they are still at the stock location with the 5.5 lift coils. So I could do something there.

Again, just trying to learn, if there is a really cool cheap method of getting some more flex, I might be up to it.

Thanks, Derek

 

[70_Steve]

Some info and more links here:
http://www.wt4wheeling.com/tech/wristfront.htm

 

[green50gt]

Ok, I was just reading through some of the archives....Why in the heck would you only wrist one side? I just figured you would wrist both sides?

If you only wrist one side, how does it help the other?

 

[trailpsycho]

If you go back and read the post 70_Steve provided, the rationale is described pretty well...basically, wristing the driver's side would wreak havoc on the front driveline if it is allowed to move too much since the front differential is offset toward that side. When the passenger side is wristed it allows for the travel without contracting/extending the front driveshaft which would result in more bind and lead to a decreased drivehaft (u-joints) lifespan. The rest you should be able to glean from the article. Good luck and let us know what you decide on.

 

[ET]

Here some picture of a wristed arm by Quinn Dusenberry.

 

[Broncobowsher]

The wristed arm is equilivent to disconnecting a sway bar on other vehicles. The catch is that the Fords use the arms for axle location, sway bar effect is secondary. If you do too many things, parst start flopping around.
Do only 1 thing. If you double wrested armed a vehicle, there would be nothing to control the axle torque. This includes braking torque. I have doubts about the vehicle even being able to stand upright without the front axle falling (rotating) out from under the front. If it managed to stand, the first time you tried to move it in your driveway it will fold under you.
Any single item will loosen the front end up completely, 2 hinges and it will fold on you. More isn’t always better. The neat thing about the wristed housing is that the brake torque is goes through both arms, not just one like the wristed arm.
Long arms have a few other effects other then just increasing flex. One is that the caster change is reduced as the suspension is cycled. Another, possibly bigger effect is in braking. With the standard length arms, brake torque is applied toward the front/center of the frame. This lifts the front slightly, reducing brake dive. With long arms, the upward force is further rearward on the frame. This helps lift the rear of the bronco during hard stops and does not offer a counter effect to the natural weight transfer to the front. Long arms should cause more brake dive in hard braking.

 

[huged29]

Ok, I was just reading through some of the archives....Why in the heck would you only wrist one side? I just figured you would wrist both sides?

If you only wrist one side, how does it help the other?

You can't wrist both sides, if you did that then there would be nothing to stop the axle from spinning and snapping your steering and driveline and everything else the front axle is connected to. When you wrist one arm, all you are trying to do is relieve some of the bind in the radius arms. Stock radius arms act like a big sway bar and if you partially disconnect one side it allows for more sway.

looks like i was a minute late

 

[Dennis]

Take three pencils/pens. Use one as the axle and the other two as the radius arms. Tape them together so the axle doesn't rotate in the radius arms. Then simulate the movement of the axle during a wheelin trip. That was all I needed to see.

 

[Broncobowsher]

Take three pencils/pens. Use one as the axle and the other two as the radius arms. Tape them together so the axle doesn't rotate in the radius arms. Then simulate the movement of the axle during a wheelin trip. That was all I needed to see.

I find it easier to show people by opening up a large paperclip to deminstrate the axle and radius arms. Also helps explain bronco lean.

 

[76Broncofromhell]

If you are looking for the least "ghetto" way to gain suspension flex I would go with manufactured long arms. Wristed arms are cool, I've run one; but my extended arms perform almost as well in flex work awesome on the road There's a little bit of sway....oh well.

 

[green50gt]

You can't wrist both sides, if you did that then there would be nothing to stop the axle from spinning and snapping your steering and driveline and everything else the front axle is connected to. When you wrist one arm, all you are trying to do is relieve some of the bind in the radius arms. Stock radius arms act like a big sway bar and if you partially disconnect one side it allows for more sway.

Correct me If I am wrong...but wouldn't the SPRINGS stop it from spinning? In the idea of say your drivers side is up on a rock, because your drivers side is also wristed, you have a lot more stuffing on that side, and that allows the passenger side to drop that much farther? Isn't that how it would work from THAT SIDE? You have the springs to stop it from turning into a helicopter.

Now reverse the the situation...the passenger side is on the rock...My guess is the driveshaft would have came apart from the drivers side dropping so far. So to cure that put on a limiting strap?

Has anybody actually tried it? I see what you guys are saying. I understand how it is supposed to work. I'd like to be the devils advocate about it for a minute.

Derek

 

[Big Nuf]

I say....go for it. Take some pics so we can all see how well it works %)

 

[TexasBronco]

Try it. And if it ends up not working sell one of your arms to off set the caost of any damage that may occur.

 

[Dusty]

I'm not so sure you understand yet how the wristed arm works. Wristing one side doesn't make that side flex better than the other. All it does is relieve the bind in the "sway bar". It doesn't matter where along the sway bar the joint is located, so it will work equally well on both sides. The reason the passenger side is usually wristed is because the driveshaft is closer to the driver side, so its more beneficial from a driveshaft angle standpoint to have the rigid side closer to the diff. Wristing both sides would provide no additional benefit in flex, and would have catastrophic consequences for your driveshaft, u-joints, steering linkage, trac bar, and both on and off-road handling. As has been said already, the radius arms are a "control arm", used to locate the axle the proper distance from the frame (from the point of the radius arm mounts), and also to control the rotation of the axle. If you wrist both sides you will have no rotational control (because there is no longer a control arm that will perform that function), and greatly decreased control of the distance from the frame (as the distance can be shortened under braking or hitting a rock by flexing the hinge in the radius arm, effectively shortening the radius arm). If you think the coil spring will keep it from rotating you're greatly mistaken. First of all, have you taken a good look at the clip that holds the bottom of the spring to the spring cup and radius arm/cap? Its not designed to be strong, just to hold the last coil of the spring in the cup on full droop. Second, even if you were able to bolt the lower most coil rigidly to the radius arm and cap, the spring itself provides no control in any direction. In fact it might prefer to bow rather than compress, if there is no other rotational control on the axle housing. And that's just under normal up and down travel of the axle. Throw in the rotational forces of acceleration and braking, or the forces of bumping into a rock, and you're all done. It will pretzel your track bar and drag link, grenade the driveshaft u-joint and probably destroy the yokes and overextend the slip splines when you hit the gas or the brake, and the axle rotates because there is nothing but a spring (which is designed to FLEX) attached to it.

Dusty

 

[Broncobowsher]

I was just out playing this past weekend. One of the rigs had custom homemade radius arms. The passenger side was built with a slider that acted just like a wristed arm. The drivers side was built the same way, but without the slider. All mounted on heims. The one heim on the drivers side broke, basicly making for a wristed arm on that side as well. The result was that everything went loose. By shifting into reverse, we could open op the front end enough to change the broken heim. That was after we put the driveshaft back together because the axle rotated so far the long travel slip yoke pulled out. The vehicle couldn't be moved with the broken heim, we had to fix it on the spot, just so it could be moved.

 

[0313]

Correct me If I am wrong...but wouldn't the SPRINGS stop it from spinning? In the idea of say your drivers side is up on a rock, because your drivers side is also wristed, you have a lot more stuffing on that side, and that allows the passenger side to drop that much farther? Isn't that how it would work from THAT SIDE? You have the springs to stop it from turning into a helicopter.

Now reverse the the situation...the passenger side is on the rock...My guess is the driveshaft would have came apart from the drivers side dropping so far. So to cure that put on a limiting strap?

Has anybody actually tried it? I see what you guys are saying. I understand how it is supposed to work. I'd like to be the devils advocate about it for a minute.

Derek

The springs support the vehicle wieght, they dont help for keeping the axle in place. If you wrist them both your axle will fold under the vehicle. It would almost be the same as removing both radius arms.

The drive shaft has nothing to do with holding your axle in place. If you are really wanting to make your vehicle flexy the best thing to do is to make it 4 link.


I wouldnt try the wristed anything, axles or radius arms. Too many weak spots i think.

 

[Steve]

I wouldnt try the wristed anything, axles or radius arms. Too many weak spots i think.

My wristed arm is much stronger than a stock arm. Don't have a pic handy, but can post one tonight.

I did leave the pin out one time coming home from a local trail just to see how it would drive on the road without it. It was fine until I got on the brakes hard, then you better be holding tight on the steering wheel if you want to stay on the road. There's no way you could drive with both arms wristed.

 

[green50gt]

EXCELLENT. That was the feedback I was looking for. I myself need detailed explainations of what something doesnt work, not just a "oh it just won't work" kind of thing.

Thank you.

I am on my way to the local machine shop to see what this might cost me.

Thanks,

Derek

 

[tonto]

These guys sell them,

Driven Auto Parts

 

[BUCKETOBOLTS]

I bought a set of spare radius arms the other week. I was thinking of extending them but was not ready to start hacking of the mounts just yet. So I wristed one of them. I think it turned out pretty well. Though I still plan on wristing the axle housing when I get the extra cash for the kit. I have $40 invested instead of $400. I know which one is supposed to be the better way of doing things, but a little experimenting never hurt. At least not to bad.

Now I have to modify my shock mounts. I think I will just go with the F250's. Then probably replace the front driveline with a long travel unit. And of coarse you can't forget the rear, it needs an in board mount for the shocks.