Leveling radius arms

[CopperBronco]

Been reading the threads, but getting mixed signals. I’m replacing my steering and c-bushings, etc… I restored c caps and radius arms completely, and have brand new c bushings. Like everyone else can’t get the radius arms within 1/8” of each other, after some fidgeting with the bolts I got it to 5/16”…. But want to avoid a bad Bronco lean, what’s the tolerance for those radius arms as you drop them to the ground?

My floor is level and it appears axle and jack stands are as well… so hopefully no false positives on my part…

Hoping for concrete details on how to fix as a solo act. The bolt / unbolting is tedious and I’m told to avoid using an impact to not risk breaking threads.

 

[SteveL]

I think bc had a good write up on it in their tech section.

 

[armynavy17]

I personally wouldn't hesitate to use an impact to tighten things up. Just as long as they're started by hand and torqued to spec by hand at the end.

 

[armynavy17]

Also, the "book" way of installation is to bolt the ends of the radius arms to their brackets then tighten up the caps evenly. Might be worth a try, can always unbolt and see where you stand

 

[CopperBronco]

I wondered about putting them into the frame to hold them still. I’ll remember that next time. Was afraid it’s just twist the frame/ body since it’s known to cause Bronco Lean when you don’t get them even.

I ended up taking a ratchet strap to one bar and wrapping it around the back frame threads of radius arm, and attaching to tire of another car to hold it down. Then I loosened the other one, propped it up about an inch and a half, then tightened down from the top of c cap a little more than the bottom and I got the last bit out, now only 1/8” apart, so wasn’t too bad. Even with ratchet strap it started to lift up some while tightening the other that was propped up, but got me that last 1/4” out of it.

As for an impact, I’m told you can break threads too easily inside of radius arms… sounds like an expensive mistake, but maybe that’s just someone doing CYA, vs being practical, thanks!

 

[DirtDonk]

This is one of the areas that is helped by making sure you lubricate the bushings very well.
Even though they’re still going to be positively located and squished up pretty tight by the metal, it gives you just that little bit of extra slide while things are beginning to be tightened down.

As far as the impact, sure you can break them off if you use the impact all the way to the end. But I doubt you can harm them simply by using the impact to speed things up while drawing things up.
As with all things you just need to be careful and pay attention. If it resists spinning with an impact, stop right there and find out why.

One of the possible issues is that these bolts were often pretty rusty and could have deteriorated up by the head so severely that they were weekend. Using an impact could certainly snap those off.
They also got rusty and filled with gunk out back at the exposed threads sitting around for all those years.
When they’re badly packed and rusted the threaded holes in the arms can be damaged by the removal of the old bolts.
Putting them back in with an impact could serve to make things worse.

Those are just off the top of my head though. I’ve never used a power tool for installing these myself. Always just a hand ratchet drawing them up alternating one corner at a time.
But I have done them successfully with the arms in the frame brackets.
You’re not gonna twist the frame by doing this, and if you have the bushings lubricated and the surfaces clean and follow the procedure going slowly one bolt at a time, you can do it without causing a lean.
Not every time maybe! But it can be done.

 

[CopperBronco]

Good to know! I got it all perfectly aligned out of the frame and only had to move arms in with a ratchet strap by about half an inch or so to align with center of holes…

One other question I tightened bolts until c caps and arms touched each other. Do I torque down to 90-110 ft lbs with weight off vehicle? Or only once weight is back on? My gut is the latter. But was wondering if arms can continue to shift while I torque down? Would hate to get it all snug and have it shift again. I haven’t tried torqueing down yet, but I can’t imagine bolts will go too much farther now.

 

[CopperBronco]

Oh, and yes I had every single surface touching one another around the c- caps greased up with lube that came from Toms for it.

 

[DirtDonk]

One other question I tightened bolts until c caps and arms touched each other. Do I torque down to 90-110 ft lbs with weight off vehicle? Or only once weight is back on? My gut is the latter. But was wondering if arms can continue to shift while I torque down? Would hate to get it all snug and have it shift again. I haven’t tried torqueing down yet, but I can’t imagine bolts will go too much farther now.

You are correct. Once the caps are touching the arms nothing is going to shift anything else, including the bushing, just due to applying more torque.
You’re only applying torque on metal to metal. Everything that’s already tight is going to stay tight.
The question about whether to do it with the weight on the ground or not is a really good one. I’ve never done it that way, but the theory is sound.
I would say only if you leave them relatively loose though, as opposed to already cinched up against each other like they are now.

Could be worth a try.
I think others have tried fixing lean conditions that way before. By loosening all the bolts on the caps with the vehicle still on the ground.
I seem to remember it didn’t change anything, but that doesn’t mean that it wouldn’t help avoid a problem if you did it ahead of time.

But I still say that the difference between how you have it now and final torque will have zero effect on anything.
As far as the bushings are concerned they are already torqued.

 

[CopperBronco]

You are correct. Once the caps are touching the arms nothing is going to shift anything else, including the bushing, just due to applying more torque.
You’re only applying torque on metal to metal. Everything that’s already tight is going to stay tight.
The question about whether to do it with the weight on the ground or not is a really good one. I’ve never done it that way, but the theory is sound.
I would say only if you leave them relatively loose though, as opposed to already cinched up against each other like they are now.

Could be worth a try.
I think others have tried fixing lean conditions that way before. By loosening all the bolts on the caps with the vehicle still on the ground.
I seem to remember it didn’t change anything, but that doesn’t mean that it wouldn’t help avoid a problem if you did it ahead of time.

But I still say that the difference between how you have it now and final torque will have zero effect on anything.
As far as the bushings are concerned they are already torqued.

Never done which way? With weight on vehicle?

 

[DirtDonk]

Correct.
I’ve done it with the radius arms attached to the frame brackets, but never with the coil springs reinstalled and the weight of the vehicle on the axle.
This is because it’s kind of hard to do that due to the lower spring cups needing to be bolted to both the caps and the radius arm at the same time.
You would have to undo one of the bolts at least, then loosen the caps allowing them to separate, then torquing them back down. All done with the tires on the vehicle.
All very awkward and a big pain.

The next best thing of course would be to have the axle on jackstands and the tires off. This way you could put the weight of the vehicle down on the suspension and axle and even bounce up and down on the front bumper if you felt like it.
But it’s still a hassle.

 

[CopperBronco]

Makes sense!

 

[CopperBronco]

Back at this thread, got my Bronco all put together and took for a test drive, need to go in for alignment as I got a death wobble around 40mph. , will do that VERY soon… all adjustable so that should be fixable.

The bigger problem is now that I drove it and having axle centered and Bronco lean gone before I drive it, after test drive I now have a 3/8” lean…. My coil springs measure the same, but from back of radius arm near the frame to the ground, my passenger side is 3/8” higher now.any explanations? Or ideas? I’m assuming c-bushings can settle more while you drive it? What’s frustrating is I leveled the radius arms to within a 1/16” when axle was removed. Hoping I don’t have to tear apart again, and even if I did, not sure I’d get a different result now.

Open to ideas or solutions. Thanks!

 

[nvrstuk]

Yup, sometimes that happens when tightening up the caps and getting the arms level and then bolting it in and driving it, it will come back a bit.


I have not found a way to fix it w/o tearing it down again- sorry.


I was the guy back in the '90's that figured out that the new long travel soft springs would create lean problems when the preload on the new spring design (and since they ride so nice- softer spring rate) the vehicle now leans because of the bushing preload on the springs. We had rigs leaning left or right, no rhyme or reason!!

I figured it out by accident and if the rest of your rig doesn't have any other contributing problems this WILL take care of it.

For 15 yrs or so all the Bronco sites or any place selling Bronco bushings &/or springs had my write up that I posted it up on- - Broncofix back in the day (Paul remembers!!)

Good luck, it works!

 

[DirtDonk]

Don't tear it apart again just yet. Just drive it.
My stock Bronco used to lean now and then and I only noticed it when parked on a flat surface when actually looking for it. And the next day it would be gone, or leaning in another direction.
Sometimes it's "Bronco Lean" and sometimes it's just lean.

What exactly does your Death Wobble do? Is it repeatable on just a certain road surface, or does it happen every time you get to 40mph or so? Shakes the steering wheel right out of your hand and will only stop once you've slowed down to about 10mph or less?

paul

 

[CopperBronco]

Don't tear it apart again just yet. Just drive it.
My stock Bronco used to lean now and then and I only noticed it when parked on a flat surface when actually looking for it. And the next day it would be gone, or leaning in another direction.
Sometimes it's "Bronco Lean" and sometimes it's just lean.

What exactly does your Death Wobble do? Is it repeatable on just a certain road surface, or does it happen every time you get to 40mph or so? Shakes the steering wheel right out of your hand and will only stop once you've slowed down to about 10mph or less?

paul

I didn’t test it again, I was going about 40 and felt it start to wiggle steering wheel back and forth and backed off the gas and it was fine still going 30mph… figured I’d get alignment first and re-test… make sure toe, camber, and caster are where I want them. The axle shifted a bit too, about a 1/4”, what’s the tolerance for centering axle under the frame?

And I won’t tear it apart again, I don’t have time for that, it can just be crooked. Or I’ll shim the underside of the coil cup.

 

[CopperBronco]

Yup, sometimes that happens when tightening up the caps and getting the arms level and then bolting it in and driving it, it will come back a bit.


I have not found a way to fix it w/o tearing it down again- sorry.


I was the guy back in the '90's that figured out that the new long travel soft springs would create lean problems when the preload on the new spring design (and since they ride so nice- softer spring rate) the vehicle now leans because of the bushing preload on the springs. We had rigs leaning left or right, no rhyme or reason!!

I figured it out by accident and if the rest of your rig doesn't have any other contributing problems this WILL take care of it.

For 15 yrs or so all the Bronco sites or any place selling Bronco bushings &/or springs had my write up that I posted it up on- - Broncofix back in the day (Paul remembers!!)

Good luck, it works!

Not sure I’m following… are you saying replacing coil springs to older style stiff ones fixes this? And that new progressive coil springs cause lean?

 

[nvrstuk]

Stiff springs are SO STIFF that we (informal survey decades ago) found that the small amount that the bushings twist/rotate the cap/arm/lower cup that a soft, progressive rate coil will compress some and a stiff old school F150 or Rancho type coil would not. Hence the lean.

Who wants to ride on an old skool stiff coil??? Nobody right!??

Now you gotta remember that if you have ANY other issues like crushed body mounts, bad rear leaf springs, bent frame, etc then obviously this isn't the fix.

I've had at least a dozen of guys email me over the past 3 1/2 decades and flip me *$&%(#@(#$ saying that I was full of stuff... really.

Wish ya the best

 

[DirtDonk]

I was going about 40 and felt it start to wiggle steering wheel back and forth and backed off the gas and it was fine still going 30mph… figured I’d get alignment first and re-test… make sure toe, camber, and caster are where I want them.

That’s just a wiggle or a shimmy then. Might even be bad ones, but don’t call it a death wobble because that is a different beast altogether!
It literally tries to take the steering wheel out of your hands and shakes the front of the truck so violently that it can break things if you don’t slow down to get out of it quickly.
You’ll know it if you ever experience it. It’s very high on the “pucker factor scale“ especially in Broncos.

Getting it aligned is a great idea. Most modern alignment shops will only adjust the toe-in for you, but at least they can give you a reading on what your caster and camber are.
Don’t get out of there without at least taking a screenshot of all the settings.

A lot of modern shops tend to “run out of printer paper” and don’t have anything to give you, or they tell you that since they can’t be adjusted you don’t need to know anyway.
Don’t let them pull that one on you!

The axle shifted a bit too, about a 1/4”, what’s the tolerance for centering axle under the frame?

Tolerance is whatever you’re willing to fine tune it to.
I’ve never heard a specification but have usually cited a 1/4 inch or less as something you don’t need to correct for.
But if you have the patience to make it less, so much better!

 

[CopperBronco]

Got it… death wobble will make me think twice…! I’m new here, hadn’t had any true pucker moments, just newbie mistakes like when my tie rod puller snapped off and nicked my finger… luckily no broken bones, but could have been a lot worse! Won’t make that mistake again!

Also worth noting it was a shimmy and I didn’t have steering stabilizer on because Duff recommends you skip it with their new dual sport Heim steer… but I’m gonna put one on anyways. It’s been ordered.

As for alignment I went and got one before I started to get a baseline and make sure I bought the right degree C-bushings… so I’ll have a good before/after comparison.

Thanks everyone! Hopefully alignment will solve the shimmy… , or stabilizer.