TTB Set up

[tactical328]

This may be a stupid question but I have been trying to figure out what the proper method for setting up the front ttb is? Are there any rules to follow when picking locations for mounting radius arm to frame brackets? I have some extended beams and radius arms, is it simply a matter of making sure each TTB arm can cycle roughly vertically relative to the frame without binding? or are there other concerns to be aware of?

Thanks for the help!

[hobbyturnedobsession]

That my friend is a loaded question. In short, it depends on the fabricator. My radius arm brackets locate a hole on each side of the frame in the same location to give me the right spot to mount them. Some arms aren't long enough, or, don't do that. It would be more helpful to take pictures and explain in detail what you have going.

[tactical328]

Well I have some threat arms and beams just trying to put it all together, no instructions were provided so I'm trying to figure it out myself. I guess more importantly I'm trying to figure out what the important mechanics and geometry are at play with TTB and radius arms and make sure that I am not overlooking something.

With the radius arm to frame bracket I am wondering where on the frame longitudinally to mount it, there is some play when locating each beam fore and aft. At ride height I would assume** that you would tend to want the beam to be favoring fore (towards the front of the truck) as the fixed radius arm will cause the beam to track rearward through the arc of suspension travel from droop and full bump.

[tactical328]

crappy ttb.png (5.74 KiB) Viewed 2276 times

so my crappy drawing here trying to splain what i'm talking about. The red arc being the travel of the radius arm and the green imaginary beam. as the suspension cycles the radius arm would be moving rearward slightly at full top and bottom. The beam to radius arm mount controls the caster of the beam already so I don't think it would change if the location is pushed fore/aft... am I missing any important piece of the geometry?

[hobbyturnedobsession]

You're looking to far into it at that point. There are nipples on the frame rails around the a pillar that are equidistant on both sides. Mount your beams and move the beam fore and aft. I push my beams forward about an inch which is about as far as you can push it without having binding in the beam bushings, or other problems. His radius arms should have locate locations they will bolt to before having to drill, so give him a call. I will say this, you will want to push the beam forward as far as you can if you want to run 35s and keep from smacking your ac box. Bolt up a beam and radius arm and get it close to where the beam would be positioned then check left to right to verify a locate hole. That is where I would start. Your drawing is close, but the radius arm also moves in a side motion which really starts having fun with geometry.

[tactical328]

Ok well i figured there should be some sort of datum or locating hole but I haven't heard anything from Dave at threat.

[tactical328]

Any issue with front driveshaft angle when pushing the driver beam far forward as possible? I measured a few degrees of misalignment on the third member. anyone have experience with this being a problem when running 4wd?