Steering "dead zone"

[pcf_mark]

Now that I have my alignment all beautiful I am enjoying the drive a bit more!
But in my never ending quest to make my '68 Bronco handle like my CTS-V I ask this question.

I have nice tight steering parts - tie rod/drag link, solid coupler from Bronco column to the Bronco power steering box. My steering has a dead zone or area where a little bit of steering input has very little or no change in the vehicle direction. In my experience older cars all have this to an extent but this seems a bit much.

1) Is this normal?
2) If the box is rebuilt will it actually make a difference?
3) I am exceptionally handy - can I the parts anywhere to do it myself?

 

[broncnaz]

Your asking a lot or should I say next to impossible for a bronco to handle like a CTS-V.%)
Basically its going to be normal parts wear and even tight parts can still have a little play it all adds up. Even just suspension height can affect the steering feel.
But usually the steering box itself will have some play unless its new or rebuilt properly. I've yet to find a source for the parts to rebuild the steering box worm and piston properly as no kits offered have the rollers much less in the oversizes needed to tighten up a worn box.

 

[DirtDonk]

Hey Mark. I know you said all the alignment stuff was dialed, but in what way? Has this been discussed in another thread I can use to refresh that info, or is this a new line of thinking you're running now?
If new, we'll need to know what you've got, what you've done, and what other changes are in force, or will soon be.

For instance, have you lifted the truck? And if so, have you re-centered the front axle, re-centered the steering box, added an adjustable draglink and tie-rod assembly, torqued all the components and set the tire pressures?
Re-reading your sig, I see that you're at stock height. But that you have front discs.
What year is your Bronco, and what disc brake setup did you use?
Did you change the steering linkage when you changed the brakes?
Are you running manual or power steering?

What are the exact alignment readings? Toe-in, Camber and Caster? What is your tire size, wheel size and offset, and tire pressure?
What type of tires and how worn are they? Brand new, or older?

Just a few needed bits of info.

Paul

 

[blubuckaroo]

There are a lot of steering components on a Bronco. All the components need some slack to work properly. The total slack from all the components is what you end up with. If you suspect the steering to be too loose, I'd recommend you get under the car and observe all the components while a helper turns the steering wheel back and forth through the "dead zone." You may find a loosely mounted steering box or worn out rag joint is the culprit. I've even found loose trac bar bushings that way.

 

[pcf_mark]

Completely stock suspension, tire size, steering box etc. No really it is actually stock!

Camber
Pass: 1.5 degrees
Driver: 0 degrees

Caster
Pass: 2.25 degrees caster
Driver: 1.95 degrees caster

I never checked the toe since I bought it because it went down the road fine. Turns out the toes was 1/2" POSITIVE which explains why it was so squirrely it would follow any change in the road. I have since set this to 3/8" negative toe. This really made a night and day difference.

I want to tighten the range where it is vague. I will do the under car look again but I did it recently and the parts seem tight from the pitman arm out. When I did my power steering conversion I used a Flaming River coupler to eliminate all question of play.

At least my CTS-V is a wagon too!

 

[broncnaz]

More caster will help Most people want at least 4 degrees or more with power steering and as was said make sure the trac bar bushings are tight.
Also consider that todays vehicles have a lot tighter tolerances when built compared to yesterdays vehicles. There is bound to be some slop in the older stuff even when everything is tight.
While you can get broncos to handle decent it will never be a luxury car type of handling.

 

[jckkys]

I bought my '77 new and it never felt anywhere near as tight as new cars. It did develop a "dead spot" about 15yrs. ago. It turned out to be the steering box mounting bolts that got slightly loose. It was hard to see through the sludge from leaking power steering fluid.

 

[Viperwolf1]

As the steering box wears you get a little slop in it. I'd rebuild it and tighten the adjustments back up. It's not too difficult. Rule out any other possibilities in the linkage and box mounting first though.

 

[pcf_mark]

Can you recommend a source for the parts?

Someone mentioned the outer u-joints but that does not make sense to me since the knuckle pivots on the king pins (no ball joints in 68). Correct?

 

[Viperwolf1]

You can get a reseal kit at O'Reillys, part #7858. Any hard parts will be a little tougher to find. Usually the hard parts are in good shape unless something tramatic has happened.

 

[DirtDonk]

...Someone mentioned the outer u-joints but that does not make sense to me since the knuckle pivots on the king pins (no ball joints in 68). Correct?

Correct. Sort of.
While the king-pin bearings are you main source of pivoting, and looseness (or even binding) from wear, the axle u-joints have to be free enough to turn with the knuckles every time.
When the old joints start to freeze up, they can play a distinct part in how the steering feels overall.

They're not usually the cause of a dead spot, but hey, you never know.
After all... It is a Bronco, after all!

Paul

 

[DirtDonk]

Completely stock suspension, tire size, steering box etc. No really it is actually stock!...

Wow. Not many of those around these parts I'm thinking.
We should start a database thread of just those that have stock EB's still. Might even make a good specialty calendar! ;D

Since you have the alignment so well documented now, make sure you make notes on anything you change in the future and what effects they have.
If you can that is. I know it's not always convenient to get a new alignment readout every time you change a spring. ;D

Paul

 

[DirtDonk]

...
Camber
Pass: 1.5 degrees
Driver: 0 degrees

Caster
Pass: 2.25 degrees caster
Driver: 1.95 degrees caster

Too bad about the difference in camber. I would consider camber shims to bring at least the pass. side down a bit. In reality, you should also bring the dr. side up a smidge too, but I'm not sure that having zero camber is actually that bad. Could be wrong though.
Not sure what your alignment guy's computer said, but the old book says that the stock spec is 1 to 2 degrees positive, with 1.5° being optimum.
Personally, with the way we wear our front tires out on the outside I'd like to see camber more in the 1/2° positive range.
The max variation is listed as 1/2 degree. So you're out on that score too.

I forget what the most desirable "cross-caster" reading is supposed to be. I've heard that there is a benefit to having more on one side, but I can never remember the details.
But like said, a few more degrees would be nice with power steering. As you've found, it drives decently with less caster than it's supposed to have (yours should be 2.75 to 4.25 degrees, with 3.5 being a desirable setting overall.
Next time you are changing your c-bushings then, maybe add some 2 degree bushings? With ball-joints, you could use the 1.5° eccentrics and put you right in the money. But with king-pins, you don't have that option on a Dana 30.
Not that you have to of course, but if you're in there changing out the old ones, that might be a good purchase.

I never checked the toe since I bought it because it went down the road fine. Turns out the toes was 1/2" POSITIVE which explains why it was so squirrely it would follow any change in the road. I have since set this to 3/8" negative toe. This really made a night and day difference.

Can you clarify something in that statement? You say at first that "it went down the road fine" but in the next sentence you say it was "squirrely" too.
Were these at the same time and mean different things? Or did the squirreliness come on at some point later?

Regarding the toe-in. With stock tires you might consider even less. Stock is 1/16 to 1/4 inch, with 1/8" being optimal. And that always worked for me.
I have tried 3/16" to 1/4" on mine, with larger tires, but usually fell back to the 3/16" as a sweet spot if I remember.
I'd be curious if you feel it drives as good with 1/8" as it does with the current 3/8".

Thanks for posting all the specs. Even if you're not in the middle of doing suspension modifications!

Paul

 

[pcf_mark]

Thanks for the questions to keep my brain going and the answers to direct me along the road. By "going down the road fine" I mean it goes straight and does not require a lot of tiny adjustments to keep going straight. It felt squirrely when it hit a bump or pot hole in the road because it would dart off in that direction. Or if you got on the brakes with the wheel turned a bit it would head off in that direction. Also going around corners it had very little grip and the outside tire would start making audible noise. The toe change really solved that since both tires are working together now.

Just to be clear - my alignment measurements are home done. I use a digital level and two machininst blocks on the rims. Camber is easy - get the level vertical and measure the angle. The castor it trickier because I need to measure the angle at full lock left and then full lock right on the same wheel. The static castor angle is the point in the middle. Toe is the old fashioned way using tape on the tire and rolling it back and forth measuring the distance front and rear. I can check all the settings with a helper in 15 minutes.

My suspension experience is all focused on cars with independent front suspension so I am not sure how the solid axle is impacted. With IFS negative camber gives you grip going around a corner to compensate for the tire rolling under. I would like to see less camber on the driver's side - maybe I could put an offset bushing in the king pin bore... Positve camber is never a good thing for cornering but zero would help tire wear.

I would like more caster also to give it better return to center feel and stability at higher speeds. I do not know what bushings are in there now I assume stock but they are polyurethane.

I'll back off the toe if I can get more caster but I thikn the extra toe is giving me better on natural back to center behavior.

Even when / if I can make these tweaks I still have this dead spot in the steering that is more concerning day to day because it there is a range of steering wheel travel that does not do anything at the wheels.

 

[bronconut73]

I have been driving my eb for 30 years. I probably have alot of play/slack in my steering but have just gotten used to it.......I guess I just don't notice it anymore.....

 

[DirtDonk]

Yeah, if by dead spot you mean freeplay, even a brand new Bronco box has more than any modern steering rack or gearbox would have. The old manual boxes had quite a bit in fact.

But that's all the more reason to have good alignment. To keep that freeplay from turning into wandering and darting and such.
I think you're right about the extra toe helping to correct for some other inconsistencies.

I'm not aware of any offset available for a D30 kingping. Only the D60 that I've seen.
Worth a check though.

Any polyurethane bushing set is going to be at least a 2° offset. I don't remember ever seeing a zero-offset bushing from the aftermarket. Rubber, yes, but poly, don't remember seeing any.

How much of a static turn of the steering wheel do you get in the center? An 1/8 of a turn is not uncommon. A good tight box might still net you at least 1.5 to 2 inches of turn.

Paul

 

[pcf_mark]

I have about a 3" range of ineffective steering - about 1 1/2" on either side of center.

Can you put the bushings in upside down or wrong? I only ask because I had them out and marked them so I could put them back in the same place. I did not find any factory markings on them at all!

I'll do a very, very close inspection tomorrow with my assistant (9 yr old girl) and report back.

 

[pcf_mark]

She is my designated "brake bleeder" by pumping them, steering checker by turning the wheel back and forth while I check and general "does this look right" expert!

 

[73azbronco]

That much play is about spot on for this rig. You might try dialing in a touch more caster, as in turn the wheels into each other one thread and see if that helps. Put it this way, if you had no dead zone, you would be weaving back and forth, much less desirable than a dead zone. As long as it tends to drive straight and not be affected by every little bump, and as long as it tends to drift downhill from the crown of the road, or as important keep in the lane as you go around a banked turn, you are good to go.

 

[DirtDonk]

I have about a 3" range of ineffective steering - about 1 1/2" on either side of center.

A "little" loose, but not completely unexpected for a Bronco.

Can you put the bushings in upside down or wrong? I only ask because I had them out and marked them so I could put them back in the same place. I did not find any factory markings on them at all!

Very easy to put them in upside down. Experts do it all the time still.
What that does is change the caster reading. With your current settings, it's very hard to imagine that they're in upside down. Not impossible of course, just not likely.
Still, putting just one half of a C in upside down could reduce your caster enough to explain the side-to-side discrepancy.

You may still be able to look at them from the side to see if you can determine which way the "thick" side is oriented.
We have a video on our site (I'll see if I can find the link) that shows how they're designed and might help you visualize what you're looking for, if you aren't already sure.

I'll do a very, very close inspection tomorrow with my assistant (9 yr old girl) and report back.

Sounds like a plan. Great times spent getting her used to "her" Bronco after all

I think you said you've already done the steering test (tires on the ground, right?), but if you do it again, keep a particularly close eye on the shaft joint(s) between the steering wheel and the steering box, AND the trackbar bushings and mounts.
Sometimes the little tiny amount of play in the trackbar can go unnoticed unless you're looking for it specifically.
Any movement in the trackbar also acts to increase the play in the steering linkage.

But you might just have a slightly worn and loose box. As you and the others have been suggesting.

Paul