Making your own radius rods?

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kelseydum

Well-known member
Joined
Jul 9, 2007
Messages
860
Location
Little Rock, AR
I was going to change my hairpins out for some wishbones to give me some clearance on the ground and my pitman arm. I was wondering if anyone has fabricated radius rods that can bolt up to the spring behind axle brackets instead of bolting straight to the axle?

Here is an idea I came up with using some split wishbones or maybe some really thick wall tubing... What do you think? Has anyone done something like this on their rod? Bending and threading the ends for the clevises will probably be the hardest part.

radiusRod_idea1.jpg


Here is my current set up. You can see I need some clearance from the ground , but most importantly my pitman arm.

draglink.jpg
 
Yeah KD, I believe the bent tubing threaded would be the hang up. Maybe just straight tubing like a bung, welded to the flange on the 'bone'?

The drawing looks sword like--kinda a theme?

Theres a good source for DOM outside of Bald Knob--usually good prices--let me know what you might need and I'll check if he has any. Stuff can be kinda hard to find. Preacher and I did some rad rod work recently and theres a material source and info on the thread in Tech Tips.

PA41
 
Let me check out some more feedback and see what I want to do. I may have to just use the wishbones as everyone else does. If I do something like this I'll PM you for the info... I appreciate it!
 
make them like this

i think you are going about this all wrong. or at least the hard way about it. if you look at yours and then look at these, you will see, you could make them out of the ones you got and not really have to buy anything. oh maybe a little longer piece to weld as a bung to the top rod. i think you would have enough clearance for your pitman arm.
radiusrod.jpg
 
flatheadgary is right. This style gives you the room you need. Though I'm using a rack for my steering and dont have the clearance problems as you showed on yours I believe you need to use something like this.
 

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Those would solve my clearance issue with the pitman arm but not the ground. I scraped the hell out of my hairpins the other day pulling out of a parking lot, and I really need the extra clearance for the ground as well.

I think the wishbone will do that. I know this is going about it the hard way (fabbing my own) but I want to see if anyone has done this... if not and I can make them strong and safe, then maybe I can make and sell a couple of sets.

I just need some good ideas for how to go about the clevis part of this.

Even if I just use the wishbones I still need to drill a hole or weld a bung in for the spring shackle to mount to (spring behind set up). Did I mention I already have a set of wishbones (free).
 
I do see what you are addressing, but the bigger problem is the angle on your drag link. It should be as close to parallel with your radius rods as possible. That allows them to move in the same arc during suspension travel. The configuration you have there is going to cause bump steer issues. I know you already set it up that way, but it is at the root of your problem here...
 
Thanks Blue Eyed Devil, I have been driving it already and there isn't much bump steer (or any really) right now surprisingly. I know the rules of bump steer are there for a reason but sometimes if you set it up "right" it still has some bump steer and some (set up like mine now) has no bump steer. I don't know why but sometimes it just functions differently than planned.

I do see what your getting at but I want to fix the clearance issues first then I'll adjust the pitman arm somehow if I have bump steer issues. Right now I'm tired of bottoming out and want to feel safe driving this thing on a bumpy road.

Any more ideas on how to make the clevis attach to the thick tubing?
 
So how about if I just cut the round tubing at an angle, push one end of the round tubing down into each perch bolt hole snug and weld in, then weld the other angled piece of tubing to the tubing already welded into the wishbone?

I would need to leave enough round tubing to be threaded a good ways. then add gussets.

This seems like some work but might be cool if I could pull it off. I might just still use the wishbones as they are meant to be used.

Now I'm not as worried about bump steer as I am this changing my caster angle. Hopefully I can adjust it through the rod ends or clevises.

radiusRod_idea2.jpg
 
Re the original drawing:

If you use 1" od .156 wall DOM, you can bend the tube; then use an 11/16 reamer to ream into the bend. The reamer will straighten out the ID and give you up to 1 inch more depth (depending on the bend radius), so that you can tap 3/4-16 UNF into the hole.

If you don't have access to a tubing bender you can fill the tube with dry sand and cap the ends (leave a pinhole for any vapor to exscape). Heat with a rosebud and bend it around a form. You can get a good result and identical sides. I'd leave both ends long and cut them to length after.
 
That's a cool trick for bending tubing. I've never tried it that way. I was thinking of just pie cutting the tubing, bend to desire and weld back up. I wasn't sure if this would effect me trying to thread it afterward???
 
If you don't need to save your existing hairpins you could make sure the arms are the same distance apart at the back as the front. You could then shorten the arms until it looks like what you want to fab. Thread the tubing and extend it at the back with a long tapered arm like you said.
 
Depending on if you plan to use the same bracket on the axle, weld the right size threaded high nut on top of the pin holes on the wishbones. You can cut open the pin holes on the wishbones and weld the high nuts in the slot.
 
go for it

I like your idea i made my own. mine don't look as strong as your drawings do I used 1-1/4 .250 DOM for mine.

I think i might need to do some more gussets on mine now [S

susp1.jpg
radiusrodtubes.jpg
 
That's a cool trick for bending tubing. I've never tried it that way. I was thinking of just pie cutting the tubing, bend to desire and weld back up. I wasn't sure if this would effect me trying to thread it afterward???

In the case of DOM (mild steel) being welded with a MIG wire, which is almost always 70 series or 70,000 pound tensile (medium carbon) the weld will definitely be harder than the parent material. The difference increases the chance of breaking a tooth on the tap when it hits the harder weld. The other probelm is that you will need a full penetration weld without over penetration (metal projecting into the ID of the tube) which would surely break the tap.

I think it would be much safer to bend the DOM without the cut and weld.
 

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