Front end alignment

[Mclock]

I’m sure this has been beat to death but I’ll ask anyway. 73 bronco 2 1/2 in lift 7 deg bushings and I’m still negative caster. Anyone heard of this before ? Thanks.

 

[serial car restorer]

How much negative caster, and how was it measured? Have you measured your pinion angle to confirm?

I've got 3" suspension lift and 7° bushings, and I'm at 5° caster with a -7° pinion angle. For you to have negative caster with your set up, I can think of a couple things to look at first, depending on how much negative you have.

Does the Bronco set level? Or is it higher in back (more rear lift or taller tires on the rear)?

Any chance the C-bushings were put in wrong? (Bottom on top, vice-versa.)

 

[Mclock]

Caster was -1 and -8. Rear sits maybe an inch higher. Same size tires I actually took out the 2 1/2 in lift in back and put in 1” lift. Double checked bushings. Ordered Tom’s radius arms with 4 deg built in. Hope this helps.

 

[Broncobowsher]

That is going to be a bent (twisted) axle. The bushings rotate the axle housing, the whole housing at once.
I would have the alignment checked again just in case the alignment machine was off (yes the alignment machines can be bad, or even a bad setup onto a good alignment machine)

 

[jamesroney]

Caster was -1 and -8. Rear sits maybe an inch higher. Same size tires I actually took out the 2 1/2 in lift in back and put in 1” lift. Double checked bushings. Ordered Tom’s radius arms with 4 deg built in. Hope this helps.

2nd request: What’s the pinion angle?
You can get a very good approximation by measuring the diff cover angle as well.

If you were at -1, and you installed a 7 degree bushing and ended at -8…that does not bode well for your bushing installation.

But the cover angle will answer it.

 

[Mclock]

2nd request: What’s the pinion angle?
You can get a very good approximation by measuring the diff cover angle as well.

If you were at -1, and you installed a 7 degree bushing and ended at -8…that does not bode well for your bushing installation.

But the cover angle will answer it.

I’m not sure what the caster was before I installed the bushings.

 

[Oldtimer]

Caster was -1 and -8. .

-1 on one side, and -8 on the other side?
What is the caster after installing 7 deg bushings?

 

[Broncobowsher]

You are not fixing 7° of cross caster on a beam axle with bushings. Not going to happen, the axle is way to rigid for that to happen.

 

[Mclock]

How about with the radius arms with 4 deg built into

 

[Mclock]

2nd request: What’s the pinion angle?
You can get a very good approximation by measuring the diff cover angle as well.

If you were at -1, and you installed a 7 degree bushing and ended at -8…that does not bode well for your bushing installation.

But the cover angle will answer it.

Not sure on pinion angle.

 

[Mclock]

Not sure on pinion angle.

I didn’t get an alignment before installing bushings.

 

[Broncobowsher]

How about with the radius arms with 4 deg built into

Still won't fix a twisted axle housing.
The outer C is 7° rotated from one side to the other. Rotating the whole axle housing won't change the relationship from left to right sides.

 

[ksagis]

Suggest you post the alignment sheet

 

[jamesroney]

You are not fixing 7° of cross caster on a beam axle with bushings. Not going to happen, the axle is way to rigid for that to happen.

He doesn't have 7 degrees of cross caster. I couldn't put 7 degrees of cross caster in a welded wedge Bronco D44 housing if I tried. There just isn't enough tube between the radius arm and the knuckle to get there. Even if you spun the rosettes out of the center, the radius arms would bring the cross caster back to within a degree or two. I remember when @lars and Jim Cole were playing with wristed radius arms and then somebody built a wristed housing. and even then...the knuckles followed the radius arm.

So no, unless somebody did half a cut-n-turn...it just didn't happen. But I'll leave it to you guys to figure it out.

@ksagis That's gonna be only way to troubleshoot this. I'm out.

 

[Mclock]

Suggest you post the alignment sheet

Suggest you post the alignment sheet

 

[Mclock]

Suggest you post the alignment sheet

 

[Broncobowsher]

He doesn't have 7 degrees of cross caster. I couldn't put 7 degrees of cross caster in a welded wedge Bronco D44 housing if I tried. There just isn't enough tube between the radius arm and the knuckle to get there. Even if you spun the rosettes out of the center, the radius arms would bring the cross caster back to within a degree or two. I remember when @lars and Jim Cole were playing with wristed radius arms and then somebody built a wristed housing. and even then...the knuckles followed the radius arm.

So no, unless somebody did half a cut-n-turn...it just didn't happen. But I'll leave it to you guys to figure it out.

@ksagis That's gonna be only way to troubleshoot this. I'm out.

Caster was -1 and -8.

I didn’t get an alignment before installing bushings.

That tells me measurements were done after bushings were installed and the results were -1 and -8.
And correct, you can't get that with bushings. The only way to get 7° of cross caster is a twisted (bent) axle housing.

I see where you are reading the 7° bushings installed and there was a 7° caster change.
What I am reading is after installing the bushings a measurement was taken and there is a 7° split side to side.

A picture is worth a thousand words. Is there a shot of the alignment sheet? We know it was after the bushings were installed, so what numbers do we have at the moment?