The Dana 50 TTB and getting it under my E350 van.

BajaSportsmobile

Baja Ironman
Those are 2wd bolt on Radius Arms made of mild steel seamed tube - all appropriate for the application.

Agile Off-Road uses 1.75" x 0.120" wall 4130 Chromoly Tube, welded and gusseted to make a one piece TTB J-Arm.

Apples and Oranges.

P.s. Jeremy's shop, WeldTech Designs, is right around the corner from Agile Off-Road. We are friends and supply him with his FOX products with our custom valving. We also provide him with all our "take-off" beams which he sells. We have a great relationship and help each other out. His 2wd products are a great option for someone not requiring 4-Wheel Drive and priced very competitively. They are the best handling 2wd lift - because they use our FOX Shocks...

Weldtec's arms

There's one professional off-road company who apparently agrees with 4x4junkie and I.
Look at the pictures below of another "professional" TTB conversion - 1/2 Ton Dana 44 and bolt on factory Radius Arms, with no travel. Very light duty.
 

philos

Explorer
The Salem Kroger doesn't look as clean as Ramsey's, but I'm still very happy to see the pics!
Looks like they used relatively short radius arms. Bump stop extended, angled spring base/mount.

Thank you!!!
 

Mwilliamshs

Explorer
Awesome of you to take and share these pics, MGM! Much appreciated.



Basically zero travel there! Realistically, considering the distance laterally from bumpstop to wheel mounting surface, I bet wheel bump travel is about 3". I'd be interested to learn their ride height, bet it's super low. I'd rather have longer, custom radius arms with better brackets further back and more wheel travel but that low step-in with 4wd traction is a decent trade off. Looks like this van gets USED considering the tire rub on the radius arm.

The Salem Kroger...Looks like they used relatively short radius arms...
Looks like stock F150, Bronco arms to me

...Agile Off-Road uses 1.75" x 0.120" wall 4130 Chromoly Tube, welded and gusseted to make a one piece TTB J-Arm....
are we to pardon the *brief commercial interruption* aka answering a question nobody asked? GAC



here's another shot of professional ttb arms. Camburg
 
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Abitibi

Explorer
Maybe nobody directly asked the question but your picture and comments were obviously directed at Agile so it's only fair that he responds with some details so you stop hammering on his products and design quality...

I do like the pictures you posted though, can't go wrong to add some reinforcement even if just for the peace of mind, thanks for sharing.
 

toddz69

Explorer
are we to pardon the *brief commercial interruption* aka answering a question nobody asked? GAC



here's another shot of professional ttb arms. Camburg
Camburg, Autofab, Weldtech, and others all use a similar design in the construction of their arms. Ramsey/Glen's design is also a great option that has been used extensively in the TTB pre-run/race market, most notably by Spirit Racing and Curt LeDuc on his trucks. Both designs are well-proven and have thousands and thousands of off road racing miles without failure to their credit.

Todd Z.
 

Mwilliamshs

Explorer
Maybe nobody directly asked the question but your picture and comments were obviously directed at Agile...

I do like the pictures you posted though, can't go wrong to add some reinforcement even if just for the peace of mind, thanks for sharing.
wrong. pictures i shared were for philos, the OP.

you're welcome too tho
 

BajaSportsmobile

Baja Ironman
I really shouldn't waste any more time on this nonsense, but perhaps someone will learn something helpful.

All the radius arms pictured are 2wd bolt on units, designed to bolt to the I-beam using the stock bolt holes. They are also mild steel...

If I were building a bolt on radius arm, I would do the same thing as there really are no other options - they need to have the bend for turning radius clearance for the tire and they have to bolt up to the existing hole, thus requiring the "bend".

I'm going to do my best to paint a word picture to describe the weakness of the design.

The important thing to note, is that where they bolt to the I-beams becomes a pivot point, where the radius arm can and will rotate inward because the radius arms are not straight. Draw a line between the point where they bolt to the I-beam and the rear pivot point and you can see that they have a "bend" built into them. This causes the design to want to buckle and bend - right where they are reinforced. That is why they are reinforced there - they would fail otherwise. It is much easier to bend a tube or beam that already has a bend in it than it is to bend a straight tube or beam. It is also easier to bend a beam that can rotate at each end around a pivot point. Bolt those radius arms to the I-beam and then weld them to the I-beam and you would greatly increase the strength of the design.

Stock radius arms have the same design, only shorter. They are the weak link in stock TTB vehicles and this is what they got the bad reputation from. If you stuff a stock F150 or Bronco into a hole, you would more than likely bend a radius arm. In fact, they were designed to bend and be a "fuse" if you will.

Our radius arms are straight, with no bend in them, so they are much stronger. They are also 4130 Chromoly which is much stronger, and much more expensive, than the mild steel used by the others. They are also welded on, so there is no built in pivot point. The Traction Beam are also triangulated to the radius arms, so the complete J-Arm is very strong. Welding additional plating to the sides of them would only introduce a new place for them to fail unless it extends full length, which we often do in racing applications. The added weight and cost would yield little in return.

It is late, I'm tired - I hope this makes sense in the morning.

Bending Moment



here's another shot of professional ttb arms. Camburg
P.s. Build what you want, any way you want... we did!
 

ert01

Adventurer
Baja... I'm glad you are still posting here. I don't have any plans to do TTB in my van, but I appreciate the knowledge and experience that you are contributing to this thread. I find it informative. Thanks
 

philos

Explorer
Thank you all for the contributions, much appreciated.
It's a beauty of a day outside today, so I'm going to enjoy some of it and maybe have a nap under a tree.
See you tomorrow :)



Sent via flux capacitor
 

bcaine

New member
Mwilliams, thanks for the links. Those are indeed some changes... Useful pictures any time there are dana50 projects.

Can't beat this bronco for relevance to setting up this project. (Edit: should have been Blazer)

Thanks agile for the info on bending moment. The physicist in me goes nuts for that stuff, and the engineer in me moves further from infancy.

As I think through the radius arm discussion, I'm hoping for some clarity from the camburg style radius arm advocates, or maybe I'm just focusing on the wrong parts of why that design may be better. How would anyone propose bolting those radius arms to the dana50? Keeping in mind that a bolt cannot go through the center of the axles.

Or is the sole reason for advocacy the type of reinforcement added? I do recall how this facet of the discussion began with an analysis of a set of the agile arms in a previous post.

One way or another it seems that you end up with j-arms when modding a formerly leaf sprung axle. To deal with the torque mentioned by 4x4junkie (I think) what are thoughts on this way of securing and reinforcing the radius arms?
image.jpg
 
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justcuz

Explorer
If the stuff I have read is correct, two important things in setting up beams is the inner pivot should line up with the center of the hub at static ride height and the tie rods should follow the same travel arc as the beam. Caster and camber settings are important too, but if you look at Agiles videos of the front end, everything travels smoothly and there is no appearance of toe in or out through the beams travel cycle.
I only wonder if he uses different inner beam pivot mounts based on desired ride height. It would seem easier to do that than move the lower ball joint out in the beam.
 

toddz69

Explorer
Can't beat this bronco for relevance to setting up this project.

One way or another it seems that you end up with j-arms when modding a formerly leaf sprung axle. To deal with the torque mentioned by 4x4junkie (I think) what are thoughts on this way of securing and reinforcing the radius arms?
View attachment 328597
The link you attached doesn't seem to open but I can tell from the title that it's the thread on Raquel, which is Ramsey's Blazer, not a Bronco :). A neat project nonetheless and I hope to see it on the road (or trail) someday.

As for the method of attaching the radius as shown in the photo, that's a great method as far as I'm concerned (checks all the buttons on my good engineering checklist) and I noted in an earlier post in this thread that it's been used a lot over the years by various desert racing Twin-I-Beam and TTB trucks.

Todd Z.
 

BajaSportsmobile

Baja Ironman
Todd,

You must not be able to see the picture, as it is a 5 lug Dana 44 TTB, most likely on a Bronco of F150 and not my Blazer. You are of course correct about it being a proven system.
 
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