Front suspension/Caster Process

[Apogee]

I’ll keep my eyes open for another 44. I researched the 1310 u joints and they operate fine at 10° and their max angle is 15° with warnings that at that angle they will wear quickly. Lots of discussion about vibration at speed when 44 engaged, going over big bumps that drop front axle way down, etc. but none of that will happen in this Bronco. I still have DS installed. It has a working angle of just under 10° now. Only time it will go into 4x4 will be to turn gears or test operation but even then only a few mph and short distance. Given the purpose of this build, I do not think there is any concern.

Thanks for the documenting your process and the results...like you said, there are a lot of different experiences out there that may or may not agree.

FWIW, axle droop versus front pinion angle tends to be much less of an issue on EB's and other radius arm equipped vehicles, as the pinion angle relationship to the radius arms is basically fixed, less whatever compliance the C-bushings offer, so if what you have works at ride height, it should work throughout the range of front suspension travel as well. When running extended radius arms, then length of the arms no longer matches the length of the driveshaft, so the flatter arc that the front axle travels down tends to make front driveshaft angles worse, at least relative to the factory radius arms, which is what I experienced on my '77 with CAGE long arms. It required the offset u-joint to just to function at all, and now it's getting the cut and turn treatment with a HP D44.

 

[jamesroney]

So, why did this Bronco need 8 degrees caster and others were "fine" with 2 degrees?

...Because they all need 7 degrees. (...welcome to the team.)

When you have 7 degrees of caster, it drives with confidence, and the rest of the components can be normal. Nothing else matters.
When you have 2 degrees of caster, it lacks confidence, and EVERYTHING else matters.

Jump on your mountain bike and try to ride with no hands. Then get on your road bike and try the same thing. THAT is what caster does for you.

 

[ntsqd]

The difference isn't the Broncos, the difference is who's reporting that 2° is "fine."

 

[DirtDonk]

Hey, I resemble that remark! Hah!
Just to be clear, I never said more is not better. And I always strive to put more in when I can.
I just said that mine worked very well, even with what it had.

 

[ntsqd]

I'm not accusing anyone of anything, just pointing out that what is "Fine" is different for each driver. Much like brake pedal feel, highly subjective.

An illustrative anecdote: Cale Yarborough was famous for going fast in any car. Put him in the best tuned car for that track on that day and he'd run up front. Put him in the most evilly handling roach of a car on the track and he'd run up front. "Fine" for him is far different than "Fine" for me (& there's no way that I'd have ever been able to run up front in a Cup car race!).

 

[DirtDonk]

Nah, didn’t take it that way either.
I totally agree that everyone’s tolerance/perception/ability/reference points and other variations will vary.

And I thought of something during all this. What if the original readings that I’m going by for mine were incorrect?
It’s doubtful, considering it was a typical alignment rack computer read out. But it was done 30+ years ago and maybe there was some strangeness going on.
Then again, I’ll have to dig it out to make sure my memory isn’t fading. Pretty sure that’s only my selective memory fading, however.

 

[DirtDonk]

They were all the same as far as I know.

If I’m remembering correctly, at least as far as the aftermarket books are concerned, the expected caster readings were within the same range for all years. Something like 2.5 to 4° positive.
Again, if I remember…

However, as we’ve documented here many times, perhaps accurately, perhaps not, there was a definite variation on built-in caster from the factory over the years.
It seems that from 66 to 75, there was less caster built-in than was expected. Or at least it was starting at the bottom of the range.
Sometime in 76, and 77 in most cases, there was notably more caster available to work from.
Some with 76 axles have measured low, some have measure high. Most with 77 axles have measured high.

I think it was James (actually I know it was James) who has said that every axle he’s ever tested was close to the same and within specification. Not as much as desired, so most were modified, I believe. But that they were consistently within the basic specification.
I trust his knowledge and experience, since it’s been quite a lot lot more than most of us will ever see, regarding the subject.
It doesn’t jive with what we found over the years, however. Of course it’s very possible that our methods were incorrect. It’s also very likely (in fact, virtually guaranteed) that in the past almost none of us ever measured our caster at stock height and with stock 0° bushings.
We only bothered after it was lifted or altered in someway, and we started having trouble. Or just happen to be that’s when we got curious enough to pay for some rack time.

So I’d be very curious to get some modern accurate take on all of this. A little more precision with our measuring and checking. Consistency between all parties involved as well. So that we know that we’re talking apples to apples.
So we can either prove out, or prove false, our past assumptions that earlier front axles had less caster.

 

[Torkman66]

Here is some great "proof"...I had 4.4 and it drove bad. I increased it to 7.9 and it glides down the road with one finger on the wheel.

 

[DirtDonk]

Wasn’t thinking in terms of, is more actually better. That’s a given.
Was thinking more in terms of what did they have from the factory. And how consistent were they.

 

[Torkman66]

I know, just lightening it up a bit. Your question. Are you asking if the actual C positions on the axles changed from the factory through the years?

 

[DirtDonk]

Yes and no. And that’s certainly another angle and a possibility in itself.
What I was wondering was, just how much caster was ACTUALLY built in at the Dana/Spicer factory on each individual unit, and if it was consistent or sloppy.
And to your point, if those aspects (desired caster and consistency) varied over the years.

 

[Shimmy]

Not so much. But that’s another angle and a possibility in itself.
What I was wondering was just how much caster was ACTUALLY built in at the Dana/Spicer factory, and if it was consistent or sloppy. And if those aspects varied over the years.

agree... my 77 has long arms with 7* bushings and caster came in at 5.5-6

 

[DirtDonk]

How much suspension lift?

 

[jamesroney]

Not so much. But that’s another angle and a possibility in itself.
What I was wondering was just how much caster was ACTUALLY built in at the Dana/Spicer factory, and if it was consistent or sloppy. And if those aspects varied over the years.

"Caster built in..." is a funny word. But I call it "intrisic caster"

Because caster is a direct result of wedge angle...which is controlled by the radius arm and wedges.

The original Bronco, on standard duty springs, had zero wedge angle. The radius arms were flat, and the bushings were 0 degree rubber.
(...There are almost zero Broncos on the road today in that configuration.)

When the wedges are zero, the caster is 4 degrees, and the pinion points up 8 degrees. the intrinsic caster, adds to 12 degrees. It's a useless number, but it's easier than saying "pinion up 8, knuckle back 4" Every housing that I have ever seen, worked on, measured or heard of is intrinsically 12. Drum brake, disc brake, manual steering, power steering, etc. If it's an open knuckle 44 in an EB...it's 12.

The 76-77 F100 Dana 44 Disc brake High Pinion housing is 11. (pinion up 5, knuckle back 6)

I only use the intrinsic caster number...because the vast majority of housings I get (and all of the HP housings...) end up with the wedges cut off. If you have no wedges...there is no measurable location to call "zero." If you do have wedges...they are still hard to measure without some kind of fixture/gage. All you have available is pinion angle. (because the knuckles are on the ground, the tubes are bare, the metal is hot...and the housing has no idea where it is.)

I've done this so many times, I have the measurements written on the wall of the shop. Here's a pic...

 

[Torkman66]

That's great info James. So, if the wedges were to be moved to adjust caster, that would also move the pinon down (not what we want). But if your cut and turn the Cs, then wedges are unchanged and pinon remains where it should. Do I have that right? Would you ever want or need to move the wedges? Appreciate your patience here...

 

[Torkman66]

My bad...I meant the wedges. I went back and edited my post.

 

[jamesroney]

How much suspension lift?

Bear in mind that the Jim Cole, Cage Offroad, Bloody Knuckle Garage, Duff Arms have 4 degrees of additional wedge angle built into the forging.
Most other long arms do not.

 

[jamesroney]

That's great info James. So, if the wedges were to be moved to adjust caster, that would also move the pinon down (not what we want). But if your cut and turn the Cs, then wedges are unchanged and pinon remains where it should. Do I have that right? Would you ever want or need to move the wedges? Appreciate your patience here...

Wedges get moved by people running full width, anyone re-tubing an axle, and anyone that narrows a welded wedge HP for their Bronco.
Also by people with listening problems.

No Early Bronco needs the wedges cut off. I'm pretty sure I just told @TheLimeRanger to not make that mistake.

(Thank you for fixing your Avatar. Now if I can just get you to put an ampersand in front of my name...life will be great. So it's @Torkman66 , not Torkman66. If you type the ampersand "@" in front of the name...it notifies the recipient. Otherwise, if you are not subscribed to the thread...you never know you have a question.)

 

[SLOWnEASY]

Deleted my question I'll open a new thread so I'm not hijacking this one.

 

[TheLimeRanger]

Wedges get moved by people running full width, anyone re-tubing an axle, and anyone that narrows a welded wedge HP for their Bronco.
Also by people with listening problems.

No Early Bronco needs the wedges cut off. I'm pretty sure I just told @TheLimeRanger to not make that mistake.

(Thank you for fixing your Avatar. Now if I can just get you to put an ampersand in front of my name...life will be great. So it's @Torkman66 , not Torkman66. If you type the ampersand "@" in front of the name...it notifies the recipient. Otherwise, if you are not subscribed to the thread...you never know you have a question.)

exactly what you told me.......and i listened!!