Wristed Radius Arms

[cd75hors]

Im thinkin about doin a wristed arm on my bronco. i hear is a cheaper do it yourself way to get some travel. I dont know a good way of going about it though. Does anybody know much about these?

[Hypoid]

There was a thread over at FTE in the offroad forum, looks pretty simple. Unfortunately, they want us bottom feeding, pond scum, non-paying posters to pony up for use of the search function. If I can get that kind of disregard for free, why pay?

http://www.ford-trucks.com/forums/forum63/

If you ask real nice, someone there might link you to the thread.

[Digger]

This is going to be the most common and easiest way to build a wristed arm.

http://www.broncoii4x4.com/wristed-arm/wristed-arm.php

Wristed arms are cheap and effective, but if you take it on the street, make sure to pin it. Otherwise you get some weird diving problems when the brakes are applied because all the axle's torque is controlled by the non-wristed arm. (generally the driver's side)

I have an EB 44 in my ranger. Right now I'm getting ready build a pair of extended radius arms with Johnny Joints instead of rubber bushings. IMO ext. arms can increase flex as much as a wristed arm, but you don't have the dive-to-the-corner problems that a wristed arm has, and you don't have to un-pin it when you get to the trailhead.

[cd75hors]

I have heard of doing the the Jonny joint and extended radius arms. I have been thinking and looking at those as well. I know when you do the wristed radius arm it is wise to beef up the other arm as well. I also heard of it being bent slightly. When you get done with your arms if you could do me a favor, maybe a few pointers, advice, and pics if you can get some. I'm stuck between extended arms w/ a joint or wristed arms w/ a pin. What made you go with the extended arms with the joint?

[Hypoid]

So you wrist only one arm? Hmmm, I'll have more questions later. I do have a lot of that 1/2" steel...

[Digger]

Well from an engineering standpoint extended radius arms make more sense. All torque loads are split between the two arms instead channelling it through just one. The longer you radius arms are, the more linear the wheel movement will be vs. moving in an arc. This is a plus for spring and shock movement.

If you were to look at the radius arms from above or below you will notice that they are slanted inward toward the centerline of the vehicle almost forming a triangle with the front axle. The closer the two frame mounting points of the raduis arms are to each other, the better the front end will flex because the mounts will be closer to roll axis which eliminates torsional binding at the axle. (This would be better explained with a picture)

A wristed arm increases flex by placing a joint in the passenger side radius arm which will also eliminate torsional binding, but the downside is the two-fold increase in stress on the driver's side radius arm, plus you still have the normal bind in the radius arm bushings which will limit overall vertical travel at the wheel.

The downside to extended arms is of course the increased cost of materials plus you will have to fabricate new radius arm mounts. But to me these drawbacks are easily outweighed by the increase in performance and reliability.

[Hypoid]

The longer you radius arms are, the more linear the wheel movement will be vs. moving in an arc. This is a plus for spring and shock movement.Never thought of that before...traveling on a shallower arc. How does that affect driveline length and joint angles? Do they pretty much have to compliment the travel as opposed to arc?


If you were to look at the radius arms from above or below you will notice that they are slanted inward toward the centerline of the vehicle almost forming a triangle with the front axle. The closer the two frame mounting points of the raduis arms are to each other, the better the front end will flex because the mounts will be closer to roll axis which eliminates torsional binding at the axle. (This would be better explained with a picture)Actually this part I get. The farther you go from a fulcrum (pivot point), the more linear arc you'll have for the same angle (*) at the fulcrum.


The downside to extended arms is of course the increased cost of materials plus you will have to fabricate new radius arm mounts. But to me these drawbacks are easily outweighed by the increase in performance and reliability.Any other associated costs, like steering linkages or track bar?

[Digger]

Extended radius arms may effect the front driveshaft. 1) The increased travel may push the limits of the stock slip yoke and angular travel of the u-joints. 2) Right now, my front shaft closely matches the length of the radius arms and therefore closely matches the arc travel. That mean there is very little movement of the slip yoke. (Good) When going to extended arms, the arcs will no longer match causing increased slip yoke movement. (Not as good) If I remember correctly EB's front driveshaft is already shorter than the radius arms, so this may be a non-issue for EB's.

The only additional cost associated with steering or trac-bar would be if the current setup could not handle the increased travel, but this would be true for extended and wristed arms. It most cases it should not be an issue.

[RevT]

There was a thread over at FTE in the offroad forum, looks pretty simple. Unfortunately, they want us bottom feeding, pond scum, non-paying posters to pony up for use of the search function. If I can get that kind of disregard for free, why pay?

http://www.ford-trucks.com/forums/forum63/

If you ask real nice, someone there might link you to the thread.

When was the last time you searched? I didnt pay and I can search just fine. I saw something about that a while back and I thought you had to have over like 50 post or something to search. Made no sense. Maybe they resended it.

RevT

[Hypoid]

Well whatdaya know! I'm a baaaaaaaaaaaaaaaaaaaaaaaaaaad boy, still can't search. I've had the honor of P-Oing Ken Payne. Soon after I couldn't PM or email anyone there. At over 1200 posts, I have less access than ever.

I've read up in the site announcements, for a while he had disabled many features to save bandwidth. However, if you pay to be a suporter, you have full priveledges. Read his comments about people who don't pay to be "supporters". Too damn fickle for me!!!

BTW, if you wana be famous, put "fordification" in a post, PM, or email.

http://fordification.com/censorship.htm

[RevT]

Well whatdaya know! I'm a baaaaaaaaaaaaaaaaaaaaaaaaaaad boy, still can't search. I've had the honor of P-Oing Ken Payne. Soon after I couldn't PM or email anyone there. At over 1200 posts, I have less access than ever.

I've read up in the site announcements, for a while he had disabled many features to save bandwidth. However, if you pay to be a suporter, you have full priveledges. Read his comments about people who don't pay to be "supporters". Too damn fickle for me!!!

BTW, if you wana be famous, put "fordification" in a post, PM, or email.

http://fordification.com/censorship.htm

WOW!! WOW Backwards WOW!!

What an eye opener. I could get in a lot of trouble over there but I guess I wont. Last time I saw something like this, on another forum, a whole bunch of us got kicked out. It was about backpacking of all things.

Thats what pisses me off, is you get sites that have great information and then people that dont run it properly. People are Stupid!

</soapbox>

Sorry to thread jack. Hopefully it wont get me moderated....LOL

RevT

[Hypoid]

Yeah, I stay under the radar after that crap. I sent the site name through the system's email: No good deed goes unpunnished. LOL

Back on topic, here's a link with some thoughts on LA conversions:

http://www.4x4getaways.com/LongArms.htm

I met the author last night at a Jeep G-to-G. The guy has (I think) three different engineering degrees: He's a non-stop gearhead. Now I know what I want to be when I grow up! LOL

I'm not sure if the XJ in the article is his current, but he has a Ford-Dana 44 front axle, he kept the Ford track width. After trashing a few driveshafts, he's going to try out a High-9 rear differential. A true rebel in the Jeep world. :p

[cd75hors]

Wow, thanks for the info. Lot of helpful stuff, ya really got me thinking about the extended radius arms. All that engineering stand point stuff makes sence. I'm in middle of putting a tranny in my bronco. Why I'm thinking about radius arms when I should by concentrating on tranny stuff I don't know, but thank you.

[Digger]

Wow, thanks for the info. Lot of helpful stuff, ya really got me thinking about the extended radius arms. All that engineering stand point stuff makes sence. I'm in middle of putting a tranny in my bronco. Why I'm thinking about radius arms when I should by concentrating on tranny stuff I don't know, but thank you.

It's a good time to think about radius arms. I'm going to build mine while I'm installing a new transfer case because I will need to build a new tranny crossmember.