Superduty Radius Arms

[damon1272]

Do not cut them like you have. Just cut off the lower tab weld on a longer one , plate it and bend the ears. Just as you would if you were to do a lift with the stock radius arms to get your caster. If I remenber right you have to move the lower hole about 1 and 3/4" inches for 4" of lift. I am sure that if I am wrong on this someone will correct me for the amount that the lower hole needs to move.

[SteveG]

How much caster does the truck have with the arms installed unmodified?

[CBDuner]

Driver side had .6 degrees and the passenger side had 1.3 degrees. The passenger side had a 2 degree bushing in it. The driver side bushing was adjustable, but not very much, I just know it wasn't stock. The guy doing the alignment is at Les Schwab, he's an old timer who's been there since way before it was Les Schwab. So I'm pretty sure it's not human error giving me the wrong numbers.

[CBDuner]

So here's my caster fix. Took the route BajaScott suggested and it worked pretty slick. While the truck was on level ground I unbolted the bottom radius arm bolt. To my surprise the bottom of the beams rolled forward very easily. I had a angle needle gauge on the front of the beam, and I pulled the bottom forward 7 degrees. That moved the hole 1/2" is all. So then I pulled the arms and did the following.











Only took about 2 hours to do from start to finish. The truck has 7 degrees caster with zero degrees at the bushings.

So using the super duty radius arms on my setup with 4" Rancho coils in the front, I had to move the bottom radius arm bolt 1/2" forward to correct caster.

To address the bushings, they have seemed to settle in nice and I'm going to hold off on uni-balls. The only time they seemed to be really stressed is past full droop, my droop being limited by the 5100's, it's not currently a problem.

So there's my experience with these arms, I think they're a great option for the Broncos and F150's.

[bajascott]

nice! looks great scott

[SteveG]

Very nice! Good job.

[92Custom]

Looking at picking up a set of these some time, offered him $80 for the pair with brackets. On top of being WAY CHEAPER than any of the aftermarket options, are these probably going to be stronger than the vast majority of my aftermarket pre-fabbed options? They look really beefy, and I think they also look really good. Plus you have OEM engineering with it, and I guess they're as long as most extended radius arms are anyways. So I guess I'm just asking questions for the sake of being informed BEFORE I run by butt all the way to Illinois.

Also, could I run the Deaver front coils with these with all that lift and not have any issues, so long as they were corrected for caster?

[SteveG]

Also, could I run the Deaver front coils with these with all that lift and not have any issues, so long as they were corrected for caster?

As long as you also correct the housings for camber.

[92Custom]

Of course.

I honestly wonder why these aren't a more common modification, if they're as good as they sound.

[CBDuner]

They work great. There just isn't much info on using them out there. That's why I did this thread. Just don't use my 1/2" measurement without checking yourself. Different coils and radius arm mounting places, plus variances in the beams and radius arms themselves could give you a different result. So just double check the amount to push the bottom hole forward before welding. Always tack weld first, put it on and measure, then fully weld. Takes longer but waaaayyy easier to change if you mess it up.