Front suspension/Caster Process

[Torkman66]

I've been off for the past several months, away from home. Finally, back at the shop and started driving my fresh restored 72. It now has 101 miles on it. Only real miles it is getting at this point is taking it to shows. First three got three trophies and one best of show. Pretty happy with that. Folks seem to appreciate and recognize the work.

However, jumping back into where I left off with a previous long discussion on caster. Several pages of a previous post a few months back provides amazing insight from the Bronco team. So, as I now have time to try and get this thing more enjoyable to drive, I want to keep all of you updated and ensure I get feedback from all of the gurus along the way. (You know who you are.)

As a reminder, I have a 2.5" WH suspension lift and no body lift. It is probably closer to 2.75" based on shims used to level out and get all the body lines perfect. I currently have stock control arms, 7* wedges, and the eccentric ball joint sleeve that give me about 1* more. Last Spring took it to the alignment shop to get numbers:

I was pretty happy with the caster numbers simply because folks told me it will drive good at 4* caster. Well...maybe my "drives good" and others are different. It wanders all over the road. Kind of scary at speeds above 60 on curvy roads, especially with bumps. So no, not great and not anything I would live with. So as has been offered by so many others in so many posts, I started with the easy stuff. My adjustable track bar and adjustable drag link (both new with all new components) were perfectly parallel with the original track bar frame mount and the standard pitman arm.

However, as I started to discuss the drivability issue, several folks suggested I get a dropped Pitman arm and lower the track bar. So, today I did exactly that. Here is the new look with both (This picture does not have the lowering bracket welded yet, but it is now):

Definitely lower and still very parallel. I did notice that I had to bottom out the traction bar threads to get it to fit, probably because this is only a 2.75" lift. But the body/axle side to side measurement is spot on. So, I took this new stance for a test drive. Only noticeable difference is a mild improvement in bump steer when hitting a dip or pothole. The wandering is still just as bad. Conclusion...this geometry improved the suspension based on the improved bump steer angles. But it had no effect on the drivability. Still wanders...requiring you pay attention with two hands on the wheel.

So, I also purchased the new Duff Control Arms with the adjustable caster. I will install those over the next couple of days and report back. Couple of questions/considerations:
1. Since I will have possibly an additional 7* of caster available with the new arms, should I remove the eccentric inserts in the ball joints or is it ok to just leave them there?
2. How much caster is too much caster? I am thinking I'd go to 7 or 8?
3. This is a show queen that will not be used in 4x4 so front DS angles are not a concern...if it was, I know the real solution is to cut and turn...I will do that to the next one.

I'll post more as I install the Duff arms and let you know what I find.

 

[Jeff10]

Hey Torkman66,

Nice looking Bronco!

I know you mentioned the knuckles in your post, and that rotating them isn't really an option you're considering. That being said, we rotated the knuckles on both of our EBs.

Caster (or lack of it) really affected the return to center when driving. It has been almost 15 years since we had it done; but, I do remember trying lots of things on the '71 before taking that step. With the '70 it was one of the first things we did.

From what I remember at the time, the advice I was given on the forum was that 7 degrees was the sweet spot. I can't comment on the eccentric inserts, though.

I know things change... I don't remember if adjustable control arms were available at the time, or if rotating the knuckles was presented as the best option by the shop that ultimately did the rotation on the '71. I do know that it made a world of difference on the return to center... made driving much more relaxing. (FWIW, I am much more comfortable driving the '71 on city streets and county highways than I am our '21 Jeep JL because of the feel.)

Good luck.

Jeff

 

[steelworker77]

Since this wont be used off road at all have you thought about adding a front sway bar. Was one of the biggest differences we made on ours for just cruising around. You can get the quick disconnects if you do choose to offroad at all. I run ours on the tightest setting and unhooked it the other day and took it for a spin and forgot how much a difference it actually makes. I know if wont resolve your returning to center issue but does really change the driving experience.

 

[Shimmy]

considering you have 7* c bushings already and the ball joint sleeves installed. i'd leave them both in. install the t. rex arms and that'll get you the caster you desire. use the ball joint sleeves to fine tune the camber from there.

 

[Torkman66]

@Jeff10 thank you. Will ensure I cut and turn every one in the future. This D44 is already powder coated. I’m really hoping this last attempt at increasing caster will change how it drives. 7° sounds right. I had a guy at a recent show say “7 or 8 with 9 being absolute max.” I’m shooting for 7ish. @steelworker77 what stab bar did you install?

 

[Torkman66]

@Shimmy great point!

 

[Broncobowsher]

After you are sure it is something in the front end, how is the rear suspension? How fresh are the leaf spring bushings? Are the bolts all tight back there? Spring and U-bolt.

 

[Torkman66]

Everything new front to back. All checked and rechecked. In 24hours I should have a report back as to what increased caster does.

 

[ntsqd]

I'm looking at this picture that I re-posted below and thinking that you may not be as parallel as you think you are. Let's see the same pic with the steering damper removed. Fundamentally your drag link and trac-bar are too short, and that forces that they be placed closer to horizontal. That dropped trac-bar bracket will have some flex in it due to it's (lack of) design. Which is sad because I see an easy solution that would stiffen it considerably.
In that old thread it was posted what needs to happen as the first step. Without that occurring everything is going to be a band-aid that may or may not get you where you want to be. In the process of all of this you're likely going spend more money and time than if you tore it down and fixed it correctly.

A single Bilstein 5100 up front will be at the bottom end of enough damping when set up with the 360/80 shim stack. Do you know what valve stack they have in them? Anything less than the 360/80 stack will be hopeless.

 

[TheLimeRanger]

im still sorting out my own issues (doing a cut and turn as i type this). what tire pressure are you running? at a lower tire pressure even with my crappy 1.6 and 1.8 degrees of caster the road manners were way better. Ball joints. i know you have the caster corrector sleeves in there, but what did you torque them down to?

 

[DirtDonk]

Definitely do the wiggle test. I think you’ll find that some of the wandering is due to the track bar bracket flexing because it’s not welded yet.
Now, it’s not a lot, so probably not the main source of your issue from the sound of it. When mine caused wandering, it was very minimal and I think I just noticed it because as a daily driver, I was more sensitive to it.
Since you say it’s that bad, I would also double check your toe.

If I’m reading your chart correctly, is that Toe-out because it’s reading in positive numbers?
You should adjust it at home since it’s fairly easy if you have even minimal tools. Some tape, a pen or pencil, a tape measure, and about 15 minutes of time.
It might not be as precise as the computer on the rack, but it’s been more than good enough for generations of DI wires that it certainly more than close enough.
If those readings are in degrees, what’s the conversion for your tire size?

Yes, indeed, to the tire pressures.
What are you running at all four tires right now?

But definitely do the wiggle test to see what’s going on.
You’re familiar with that? We’ve talked about it incessantly over the years, but it’s still easy to miss.

 

[DirtDonk]

Just to add, many bronco owners would kill to have caster numbers like yours.
I’ve said it before, but my 71 drove perfectly fine with just over 2° on one side and just under 2° on the other side.

Do you have power steering? Is it a six turn, four, or perhaps a three turn box?

What size is your steering wheel?

You can’t count some body mount shims as part of your lift. And for the purposes of this discussion, it’s only suspension left that affects caster anyway.

 

[ntsqd]

Those steering damper brackets bolt to the engine cross-member, don't they?

If so, it would be a fairly simple fab job to add a bolt-in gusset to the drop trac-bar bracket. Cut a piece of heavy walled tube or even some small OD Sched 80 pipe to *just* fit inside the bracket. Drill a hole thru the drop bracket above the trac-bar. The closer this hole can be to the trac-bar bolt while still clearing the trac-bar itself, the better. Cut out a piece of strap and drill two holes that align with the damper mount bolt holes near one end. Sandwich this plate between the damper bracket and the cross-member with it's excess length pointed towards the trac-bar bracket. Weld a tube long enough to reach the strap at the damper mount bolt holes from the tube above the trac-bar. The larger this brace tube can be in OD the better.
I'd do this before I'd weld the drop bracket to the frame.

 

[Torkman66]

OK, so here is the work and results today. First, a few observations and comments. I truly appreciate everyone pitching in and offering suggestions. I have learned a ton from everyone over the past few years, specifically during this build. I have also learned along the way that lots of folks have different experiences and believe that their experience is the only truth. In most cases they may be right. But I've equally learned that every ride is a bit different. How new parts react with old frames can matter and cause different results, especially with suspension and steering geometry. Finally, it is undisputed, clear, and continually agreed that the right way to dial in caster is to cut and turn the Cs. I'll agree again...caster is best solved by cutting and turning the Cs. However.....
There are always other considerations when deciding the best way forward for one's particular situation. Money, time, skill, purpose of build, how it will be driven, etc. As an experienced painter I know the best way to paint a restoration is to take it down to metal, spray epoxy, then primer, then sealer, then base and clear cut and polish all with the highest quality paints. Not a problem if you have 3k just for the materials and another 15k+ for someone to do the work. So while that may be the right way to do it, there are always other considerations...especially if you only have 3k to do the whole paint job. Point is, the "only right way" is not the only way...other considerations matter.

All that to say that I installed the T-Rex arms, dialed in 7.9 degrees caster and the Bronco drives like a new car. I now can take my hands off the wheel and it tracks straight. Going around corners with dips in the road used to make me pray no other cars were coming toward me. More than once I darted left, then right...not anymore. It turns corners with ease and returns back to center. I'm finally looking forward to driving it and will now let my wife drive it.

So, why did this Bronco need 8 degrees caster and others were "fine" with 2 degrees? I don't know the answer to that. What I do know is that I now have a bronco that is fun to drive around town. Now is the DS angle way off...yep! Will this bronco ever see four-wheel drive...nope! This is a show Bronco plane and simple. Built for someone who wants a sweet 72 that turns heads and wins best of show at car shows. Thats it, nothing more. And now it runs and drives amazing!

Next Bronco build I will cut and turn the Cs before powder coat. I will also move the rear axle back and change the perches for rear DS angle. I will also weld on a axle wrap bar. All will make for a better build...if done before powder coat and total assembly.

Finally, I know there will be others who disagree, but even though I did not take the "right" route fixing this, the end state is the same...the ride is amazing. Objective met. I for one am glad that there are aftermarket "fixes" when the right way is determined to be a bridge to far.

Thanks again for all of the advice.

 

[DirtDonk]

Fantastic report! Glad the extra caster fixed it.

 

[Torkman66]

Thanks DirtDonk! You have walked me through soooo many challenges. Really appreciate your patience and your knowledge!

 

[ZOSO]

As good as mine drives(no hands at 80mph) I think all broncos including mine can use more caster no matter what. Someone with more knowledge about the trivial things may know but did the later years with power steering have more caster built into the diff housing? For example a 72 had manual steering. Less caster required for that. VS my 74 which had power steering. Or even 76/77's?

 

[bigmuddy]

As good as mine drives(no hands at 80mph) I think all broncos including mine can use more caster no matter what. Someone with more knowledge about the trivial things may know but did the later years with power steering have more caster built into the diff housing? For example a 72 had manual steering. Less caster required for that. VS my 74 which had power steering. Or even 76/77's?

They were all the same as far as I know.

 

[bigmuddy]

OK, so here is the work and results today. First, a few observations and comments. I truly appreciate everyone pitching in and offering suggestions. I have learned a ton from everyone over the past few years, specifically during this build. I have also learned along the way that lots of folks have different experiences and believe that their experience is the only truth. In most cases they may be right. But I've equally learned that every ride is a bit different. How new parts react with old frames can matter and cause different results, especially with suspension and steering geometry. Finally, it is undisputed, clear, and continually agreed that the right way to dial in caster is to cut and turn the Cs. I'll agree again...caster is best solved by cutting and turning the Cs. However.....
There are always other considerations when deciding the best way forward for one's particular situation. Money, time, skill, purpose of build, how it will be driven, etc. As an experienced painter I know the best way to paint a restoration is to take it down to metal, spray epoxy, then primer, then sealer, then base and clear cut and polish all with the highest quality paints. Not a problem if you have 3k just for the materials and another 15k+ for someone to do the work. So while that may be the right way to do it, there are always other considerations...especially if you only have 3k to do the whole paint job. Point is, the "only right way" is not the only way...other considerations matter.

All that to say that I installed the T-Rex arms, dialed in 7.9 degrees caster and the Bronco drives like a new car. I now can take my hands off the wheel and it tracks straight. Going around corners with dips in the road used to make me pray no other cars were coming toward me. More than once I darted left, then right...not anymore. It turns corners with ease and returns back to center. I'm finally looking forward to driving it and will now let my wife drive it.

So, why did this Bronco need 8 degrees caster and others were "fine" with 2 degrees? I don't know the answer to that. What I do know is that I now have a bronco that is fun to drive around town. Now is the DS angle way off...yep! Will this bronco ever see four-wheel drive...nope! This is a show Bronco plane and simple. Built for someone who wants a sweet 72 that turns heads and wins best of show at car shows. Thats it, nothing more. And now it runs and drives amazing!

Next Bronco build I will cut and turn the Cs before powder coat. I will also move the rear axle back and change the perches for rear DS angle. I will also weld on a axle wrap bar. All will make for a better build...if done before powder coat and total assembly.

Finally, I know there will be others who disagree, but even though I did not take the "right" route fixing this, the end state is the same...the ride is amazing. Objective met. I for one am glad that there are aftermarket "fixes" when the right way is determined to be a bridge to far.

Thanks again for all of the advice.

Glad you got it fixed.
I realize your rig is a show pony but they do look goofy IMO without a front driveshaft.

With that said you can buy an offset ujoint for the front that will work with way you front pinion is angled.
I have the same issue with mine and have wheeled at slowed speed with this offset ujoint and it works fine.
I likely wouldn't rely on it if I was putting under extreme torque but it works and has worked well for me for a long time.

In the future I bought a second D44 to have the C turned and rebuilt which I will then swap for the one under my rig.

 

[Torkman66]

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.