Another Caster Question...

[nvrstuk]

A quick "Caster" story... (from 50+ yrs ago)

I remember when my Dad brought his home from Harris Ford and the 3 of us, best friend, Dad and I, were all talking in the driveway about it and my Dad offered the keys to "Skip" who could drive (I didn't have my license yet) and said take it around the block. IF YOU KNEW SKIP you already knew all the calamities, breakages, clumsy childhood stories and everyone would agree that you would think your brand new Bronco would not come back in one pc! NOBODY believed me when I told all the neighbor kids my Dad let Skip drive his Bronco... ANYway...

We went a couple blocks, turned a sharp corner and Skip was waiting for the strg wheel to return to center... well it DIDN"T and we were OK but it was a "moment" to remember at the end of the block where we lived. Dad didn't see it and so everything was OK, but...

This was a brand spanking new '69 w/less than 50 miles on it.

 

[ntsqd]

Curious that at home I can read the mph on that GPS, but here at work I can not. For those who can't read it, the displayed speed is 71.2 mph.

So you had your own MISF? I guess everyone does.

 

[Torkman66]

Here are the numbers form the alignment shop. Better than I thought they would be. Interesting as well, it actually drove pretty good on the trip. It is a bit light on the steering, but I would no longer call it "wondering". Now the question is should I go ahead and install the T-Rex which might get me in a better castor place? Might even be able to remove the balljoint eccentrics and go with the the standard ones.

 

[ntsqd]

If you can get to the point where you can use std. rubber C bushings and no eccentrics then that is where I would want to be.

 

[DirtDonk]

I think you’ve already touched on this, but to rehash something, how many turns is your steering box?
And is this with a factory steering wheel, or an aftermarket smaller diameter steering wheel?
Before the bronco, how many short wheelbase four-wheel-drive rigs have you driven?
And if others, for how many years have you driven them?

I’m just wondering if some of your wandering feel, or constant need of correction feel, is standard Bronco stuff that you’re just not used to.
That 4° of caster is something lots of us strive for. As the others have mentioned, more is better up to a point, but you’re still in the beginning of the sweet spot.

 

[DirtDonk]

Oh, and if it was me, I’d leave the ball joint eccentrics in place and maybe use them to reduce some of that camber on the left side.
Get it down near to, or just below the other side.
A little less than 1° I feel is more desirable than the factory recommended 1 to 2°.

 

[Torkman66]

Good points. I have owned a 68 Scout and still own a 83 CJ7. While I cannot claim I have driven them much, I do know my CJ has more solid road feel. But as offered, I can likely live with what I have. Once I fixed those darn eccentrics, felt much better. Thank you !!!

I should probably drive it a while now and see what I think after a few hundred miles.

The entire system is the WH kit from the steering wheel to the power steering gear box. I believe it says something about a quick ratio box. It has just under 4 full turns stop to stop.

As offered above the 4” of wheel play was with engine not running. With engine running, about 1.5” of play. So that’s good.

 

[Shimmy]

As Paul mentioned, the 4* caster is good and certainly in the realm that most folks are happy with. Will more caster help with tracking straight? yes, but it will help more with keeping steady and having the steering wheel return to center after a turn. I think Paul's question on your comfort level with driving a lifted, short based SUV is interesting. This is my first short based SUV, let alone it being a classic. @Torkman66, ultimately up to you if getting to +5* is worth it. Below is what i settled for:

3.5" lift
OTK steering
7* bushings with JD long arms
eccentric bushings
5.5-6 caster

she drives perfect now and luckily i don't have binding issues on my front DS u joint. my bronco is also a "street only" rig like yours.

 

[DirtDonk]

Sounds better all the time!
I think it’s usually a good idea, even with someone who’s been driving a rig for a long time, to drive it for a while after it’s been modified.
That way you don’t keep chasing your tail, and can make more informed changes to the mix a little later, rather than a little too soon.

 

[Broncobowsher]

When the front end checks out good, look at the rear end. Spring bushings, if the fronts get sloppy a tiny shift in the rear axle will make it feel like the front end is sloppy. U-bolts and even spring pads on the axle itself.

 

[Torkman66]

Paul, agree. I will stick with what I have now for a while. St this point, there really is no easy solution to get 1 or 2* more anyway. The T Rex arms are 1,000 bucks and still require disassembling front axle. So considering I’m st 4.5ish I’ll stick with that.

I’ll start another thread about a pulsating noise/vibration I noticed that starts about 40 mph or so. Always something to figure out…it’s why I love this hobby!

 

[DirtDonk]

To answer something that James Roney said, one actual advantage of the new arms is that they are "kinked" for tire clearance. Helping to maintain the great Bronco turning radius.
Otherwise, the factory arms were very well built. About the only dependable reason to change them out, is if they are suffering from the dreaded rust-out, undercutting the rear shanks where they go through the frame mounts. What condition were yours in?
But still, depends on what your needs are, and how important at this time.

Paul

 

[Torkman66]

My original arms were ok. Not too much rust, mainly surface. One did have a slight bend in it, but not noticeable in measuring the overall distance. from base to threaded tip. I ran a die over the threads and powder coated them. The tech at the alighnemnt shop said that my numbers looked great. Said he had done a number of older 4x4s and he usually sees the thrust angle off, rear axle not right, and caster that is negative or just 1* or 2* with lifted trucks. So overall he did not see a reason to make any changes. I would love the caster at 6* and I could get 6* or 7* with the Trex and keeping everything else the same. Would likely drive pretty solid. Have not noticed any tire rub but I also remember setting the bolt length to keep it from hitting. At least I think I did that on this truck. All of the restorations are starting top blend together! I'll take a closer look tomorrow.

Like I shared, I'll move on to trying to figure out some other vibrations and periodic noises. Cannot thank everyone enough for all of their time and help. James nailed the castor doing his own math using just the angle of the 44 cover. Paul, you are always so helpful. Oldtimer, you blowing up my balljoint pic and pointing out the eccentric issue was amazing. This is such a great group. Could not have done this Bronco without you. I'm gonna do another one soon.

 

[Broncobowsher]

I'll second the numbers look good. That is why I stated to start looking elsewhere (rear axle, leaf springs).
Forgot to ask about the track bar. Drop frame bracket? Bolts/welded? Frame flexing?
As for the bend in the stock arm, that was common to align it back in the day. Big chains and a big jack to bend stuff into alignment.

 

[Torkman66]

Just as a consideration, when I first drove the Bronco (after which I started this thread) and had what I would describe as unacceptable wondering (darting) concluding that I would not allow my wife to drive it, that was before the eccentrics were installed. I put in 1.5* caster eccentrics. Meaning that before they were installed, my caster was 2.9 left and 2.8 right. While it is clearly true that these older trucks with short wheel bases drive a bit looser, these caster numbers made it undrivable in my opinion. As noted, I have a 1983 CJ7 with a 2.5" lift and it drives great. Given the CJ has leaf springs up front, there are differences in the geometry. Point is that with whatever the stock caster was on this particular axle, the 2.5" lift and 7* bushings gave me less than 3* caster on each side. If it were not for the eccentrics, I'd be cutting and turning, or as a minimum, installing TRex arms. The takeaway for me from all of this is:

1. Any lift will require 7* C bushings
2. Eccentrics can give you as advertised 1.5* more caster (installed correctly
3. You can install 7* bushings and TREX arms and (no eccentrics) and likely get close to around 6* caster which would be awesome.
4. If you Bronco is a street driven only ride, the above all work...unless you put on a huge lift.
5. If you are going to be in 4wd much at all, absolutely 100% cut and turn the Cs.

The only other consideration is that the lift will change your rear pinon angle. Absolutely no reason not to fix that issue to near perfect using steel wedges. My rear pinon is setting at about 6* or maybe 7*. Once I am certain the exact angle (need to remove drive shaft to get a better pinon angle measurement) then I will install either 4 degree or 6 degree wedges to bring the pinon angle up to within 1* give or take.

 

[DirtDonk]

Don’t bother removing the driveshaft necessarily. Just estimate your angle in relation to the driveshaft.
In fact, after a few tries, you can do the whole thing visually.

If it’s more than 2° below the centerline of the driveshaft, you’re gonna get unusual vibrations, especially upon deceleration.
If it’s above the centerline of the driveshaft (yes, it does happen occasionally) it will give you vibrations upon acceleration.

What are the funny feelings and vibrations you are feeling currently? Or I should say, were feeling before?

 

[jamesroney]

Just as a consideration, when I first drove the Bronco (after which I started this thread) and had what I would describe as unacceptable wondering (darting) concluding that I would not allow my wife to drive it, that was before the eccentrics were installed. I put in 1.5* caster eccentrics. Meaning that before they were installed, my caster was 2.9 left and 2.8 right. While it is clearly true that these older trucks with short wheel bases drive a bit looser, these caster numbers made it undrivable in my opinion. As noted, I have a 1983 CJ7 with a 2.5" lift and it drives great. Given the CJ has leaf springs up front, there are differences in the geometry. Point is that with whatever the stock caster was on this particular axle, the 2.5" lift and 7* bushings gave me less than 3* caster on each side. If it were not for the eccentrics, I'd be cutting and turning, or as a minimum, installing TRex arms. The takeaway for me from all of this is:

1. Any lift will require 7* C bushings
2. Eccentrics can give you as advertised 1.5* more caster (installed correctly
3. You can install 7* bushings and TREX arms and (no eccentrics) and likely get close to around 6* caster which would be awesome.
4. If you Bronco is a street driven only ride, the above all work...unless you put on a huge lift.
5. If you are going to be in 4wd much at all, absolutely 100% cut and turn the Cs.

The only other consideration is that the lift will change your rear pinon angle. Absolutely no reason not to fix that issue to near perfect using steel wedges. My rear pinon is setting at about 6* or maybe 7*. Once I am certain the exact angle (need to remove drive shaft to get a better pinon angle measurement) then I will install either 4 degree or 6 degree wedges to bring the pinon angle up to within 1* give or take.

Interesting...but what would have happened if you started your restoration knowing:

A. All Bronco's need to have their inner C's rotated.
B. Lifted Broncos need their inner C's rotated more.

Then:
1. Factory C bushings work fine.
2. Eccentrics are not necessary.
3. You can run factory arms, and get 7 degrees of caster without installing inferior T-Rex arms and bushings.
4. If your Bronco is street driven, trail driven, or hammered int the rocks...you will not have any issues.

Now to the rear:
Every lifted Bronco needs to have the rear spring perches rotated. Steel wedges are tricky. Particularly on a Bronco where you want to move the axle rearward. Take another look at your profile view of your Bronco. You can see where the tire sits forward in the wheel well. A nice pair of WH anti-wrap perches, located 1 inch farther back helps.

I wish I could have helped you when your project started. Hopefully the next guy can learn from your experience.

 

[ntsqd]

FWIW I've come to use WFO exclusively for those steel angle shims. I use them temporarily to confirm the angle that is required before making permanent changes.

 

[Torkman66]

@DirtDonk The vibs happen when in constant cruise at around 45 give or take. Sounds a bit like a whoosh--whoosh--whoosh kind of like a tire rubbing in a spot. Not the best description, sorry. I'm going to do something about the rear pinon angle and see if that helps...that needs to be fixed in any case.

@jamesroney Agree 100% about cutting and turning the Cs during resto...no matter what the case. If I knew then what I know now...I would dial in the perfect caster into the axle BEFORE POWDER COATING.

As a consideration for all of the various folks out there who work on, fiddle with, or restore (to very different levels), their Broncos, much of what is done depends on skill and money available. While the "right" way is always the best way, it is not always the doable way. It is the reason why millions of bucks are spent on degree bushings, eccentrics, wedges, etc. If I was a guy of little means with an old beat up Bronco that I wanted to "fix up" on the weekends but I had never welded, would not know how to cut the Cs, and generally have to remind myself which way to turn the bolt (righty tighty) then although I am not able to either fix it right or afford to have someone else do it, I can still do bolt-on fixes that get me to a place of joy with my Bronco. I can still enjoy the hobby albiet at a novice level. Not perfect and not to code, but workable, affordable, and doable given the circumstances.

The crazy part for me is that in my case, none of the above apply. I can do all that work, have the means to buy whatever is needed, and the ability to do it right. What I lacked was the knowledge...I simply did not know at the time what I did not know. Although I can remember you or someone mentioning the idea of cutting and welding the Cs...at the time it did not seem needed. Now I understand grasshopper

So yep, I'm gonna do another Bronco and will approach it very differant. But man have I learned a lot. Have enjoyed this group tremendously. I wasted a lot of time and money learning what was right by doing it wrong the first time. But hey, its a great hobby. Cant wait to find the next one.

As for the rear axle, yes, I should have welded on the longer perches, moved the axle back 1.5", and rotated the perches to adjust for pinon angle with a lift. Its worse than that...I bought a brand new rear housing and perches from WH and welded them on to the new housing EXACTLY where the stock ones were...so proud of myself for doing that well...doing it wrong, but hey, they were just like stock. Again, if I knew then what I know now. But here we are, powder coated rear end, all assembled. Ready for a Spring Show and the solution that works and solves my pinon issue is wedges. Not the right way, but given the circumstances, the doable way.

 

[Shimmy]

FWIW, the VHT chassis epoxy in satin looks a lot like powder coat