extending radius arms

[Bronchole]

The length of the arms is not the only thing that affects the caster. The lowering of the pivot end of the arm affects it too. If you extend the arm you will likely end up lowering the the pivot point that the arm pivots on. (distance from the ground). Since the arm are slopeing down from the pivot to the axle, lengthening them will also reduce the angle of the arms to the ground. Reducing the angle of the arm to the ground will increase the positive caster angle which will usually help make your Bronco steer better. From what I understand you shouldn't expect more than a degre or 2 from this unless you go crazy intentionally dropping it

Dan

 

[Hal9000]

Don't some of the aftermarket arms have built in caster adjustments?

 

[Bronchole]

Most of the aftermarket arms have some built in caster correction of some kind.

 

[br0nc0xrapt0r]

I wonder how much higher the end would have to be to fix the caster on a 5.5 inch lift?



}------* ?

Like my radius arm drawing? sorry no fancy photo shop schematics like Tito makes.

 

[73bronco]

I just got a used set of stock radius arms that I plan to turn into long arms and started searching old posts for ideas. Has anyone bent the arms to allow more tire clearance? I know that some of the long arms available are made this way but I have not seen anyone do this on a homemade set of arms.

I made my own arms and bent them. I used a harbor freight 12 ton pipe bender and heat to do it. Came out great! The tires just touch them at full tuck and turn. When I say "just touch them" I mean they just rub the paint off but no more.

 

[casadejohnson]

That looks close to what I want to do. I'm not sure how I'm gonna approach it yet but there are some great ideas here.

 

[lars]

A data point...

I have a 4-1/2" spring lift. With 7 degree bushings installed and used for a couple of years, the alignment shop measured 1.0 degrees positive (positive caster is what you want; the top of the knuckle angles back). It wasn't enough, my Bronco wandered badly that it was tiresome to drive on the freeway. I solved the problem by cutting the inner knuckles off my Dana 44 and rotating them. I decided to go back to 2 degree C bushings while I was at it.

To get 5 degrees positive caster with 2 degree C bushings installed, I had to rotate the knuckles 9 degrees.

Since then I extended my radius arms 6 inches (I think someone linked my build thread earlier in this post). The pivot centerline is the same distance off the ground (and below the frame rail) as it was before. I picked up 1 degree of positive caster from the change, so now I'm at 6 degrees.

"Improvement" is subjective, but I'm much happier with the handling after all the surgery. It tracks true hands-off, steering returns strongly to center.

 

[Bronchole]

Oops! My negative is now positive, thanks for pointing that out Lars.

I liked your other avatar better

Dan

 

[br0nc0xrapt0r]

so with stone crusher extensions and 7* bushings on a 5.5 inch lift would I still be positive?

 

[Bronchole]

You might be on the positive side, but I doubt you would be more than 2°-3° positive. I will personally be targeting 6°-7° with 0° rubber bushings when I build mine (rubber to increase the flex)

 

[450rbronco]

what i was saying is now i have the bushings that was sent with my wh 3..5 inch lift not sure what degree and if i do stone crushers long arms will i have to much caster or not dont wanna be to much for universal joint

 

[Bronchole]

I doubt that in just doing the long arms that you would notice the drivability difference in caster angle. You might notice several other things, but I doubt any of them woud be related to the slight change in caster.

 

[lars]

so with stone crusher extensions and 7* bushings on a 5.5 inch lift would I still be positive?

Impossible to say. There was so much variation in the Dana 44s installed in early Broncos that the only way to know for sure is to assemble it and have it measured at an alignment shop. One guy I met several years ago wound up with 2 degrees positive on one side and 1 degree negative on the other.

I agree with Bronchole- the caster increase you get from longer arms is good, but by itself it isn't enough.

 

[Hal9000]

This is going to sound like a dumb question to some, but aside from bushings, is cutting and rotating the steering knuckles really the only way to adjust caster? I'm not an alignment guy, but it seems to me like I've seen plenty of vehicles with eccentrics that allow for camber/caster adjustment. Has anybody thought about maybe trying to retro-fit a D30 or D44 with them? I wouldn't think it would be THAT difficult...

 

[lars]

This is going to sound like a dumb question to some, but aside from bushings, is cutting and rotating the steering knuckles really the only way to adjust caster? I'm not an alignment guy, but it seems to me like I've seen plenty of vehicles with eccentrics that allow for camber/caster adjustment. Has anybody thought about maybe trying to retro-fit a D30 or D44 with them? I wouldn't think it would be THAT difficult...

Sure. BC Broncos sells eccentric adjusters that replace the upper ball joint sleeves. You can get up to 1.5 degrees of additional positive caster with them. In my case, that was about 4 degrees less than I wanted. Cutting and rotating the knuckles just isn't that difficult. The results are worth it.

 

[Hal9000]

Well, that's a good enough answer. I didn't realize how extreme your 5 degree rotation was in comparison to what the eccentrics could do.

 

[73bronco]

I cut and rotated my C's as well. Really not that difficult. I was having bad driveshaft angles so I installed my arms and bushings backwards to raise the pinion angle to get my driveshaft angle the way I wanted it. I was at 8° NEGATIVE caster at that point. So I cut the C's and rotated them to give me 6° POSITIVE caster with my driveshaft angle where I wanted it. I couldn't be happier! Drives straight and true and returns to center easily. And my front driveshaft has held up great now! I highly recommend cutting and rotating C's!