Steering wobble

EODMike · Jul 30, 2021

Hi y'all. I've got a 73 with all new steering components: adjustable drag bar, linkages, stabilizer, 2.5" suspension lift, new shocks, etc. (33 inch all terrains) Like many I have a "death wobble" at highway speeds. It's only occasionally while doing 65-70 and otherwise it drives well. I find that if I drive with just one hand it seems to not be as prevalent and when two hands on wheel it occurs more often (maybe in my head). Steering is pretty tight with a little bit of play which I think is normal. Is there a way to adjust the stabilizer or should I add a sway bar? I don't drive on the highway too often, but would like to whenever I choose without worrying too much.

Thanks,
Mike

Matlock · Jul 30, 2021

Death wobble is prevalent around 40MPH. Your speed of 65-70 is NOT death wobble. Are the tires new? What air pressure? When were they last balanced?
Possible bent rim? When was the last time the front wheel bearings were serviced?....Try rotating the tires to see if it goes away.

Spaggyroe · Jul 30, 2021

Things like steering stabilizers or sway bars are not remedies for D.W.

What degree c-bushings did you install with your lift? Poor alignment numbers are usually the root cause of D.W., it just usually doesn't appear when all components are tight.

Have someone turn the steering wheel back and forth somewhat rapidly from 10 o'clock to 2 o'clock while you inspect all of the steering and suspension for slop.

billh1289 · Jul 30, 2021

Can you post a pic of the front end?

DirtDonk · Jul 30, 2021

What they said. If you can continue to drive the vehicle, and even just changing how you hold the wheel helps a little, it's definitely not a Death Wobble. It's just a "wobble" or shimmy.
Lots of causes, but be glad it's not a true death wobble (yet?) because there's more you can do for a shimmy and most of it is not that expensive!

Some already asked, but a few questions.
1. What size wheels? How much offset and how wide?
2. As asked, what air pressure? Front and back? Don't use the max rating on the sidewall.
3. Did you re-center the steering box itself, or just use the steering wheel as your guide?
4. You can run without a steering stabilizer and not have shimmy, but it certainly does not hurt to have one.
5. No, a sway bar is not going to help shimmy.
6. How old are the tires? Both in years and in miles?
7. When did the shimmy start? Right after the new parts, or was it doing it before?

Those are starters, so let's see where those lead and we can go from there.

Paul

EODMike · Aug 1, 2021

Thank you all who answered, I haven't had time to get too far into checking things out yet. Had some other issues with my Bronco, left me stranded on side of highway last night in the eventual pouring rain and lightning. Got it back home and into my shop, but haven't done much else. It now is not starting (I think not getting spark, but that's another story).

To answer a few questions that I do know off hand:

One year old tires with about 1,000 miles, 33" tires (15" rims) not sure of the backspacing, but these rims have been on it for 20+ years. Pretty sure none are bent.

Tire Pressure (cold) all are right at 30 psi (one was 29). According to the tires max psi is 35. Does 30 seem too low?

7 degree C bushings (came with suspension kit from Tom's Bronco/Offroad)

I guess I noticed it when I first started going on the highway a few months ago, set up was done about a year ago. Everything is tight, checked today. Maybe wobble is a little dramatic, last night it seemed more like when a large gust of wind would blow a vehicle around some, but no wind noticeable. Sometimes it will just move over in the lane almost going into the other lane and it seems a bit loose getting back centered.

Paul, I think we re-centered the steering box. I will check more into that later this week.

Again, thank you all. I have to get it running again I think before I try to get it going straight.

Mike

m_m70 · Aug 1, 2021

sounds like you have more of a wandering problem than a wobble.

also, looks like you "set this up" a year ago (assuming added a lift/suspension kit) but only now driving it at highway speeds (last couple months) so this might not be a "new" thing.

If you can post some pics of the front suspension head on that shows the tie rods and drag link so we can see the angles.

also, if you got an alignment done post those up as well. it's good to see what your caster and toe in is

I run 33 x 12.5 at 26 to 28 in front and 26 in the rear. anything over that it just feels squirrely.

904Bronco · Aug 4, 2021

Can anyone post a picture of how the factory steering stabilizer is mounted?

I have all the parts now to do it now, and I want to make quick work of the install.

Thanks, Doug

DirtDonk · Aug 4, 2021

Is that a trick question Doug?
After all, wouldn't it normally be you posting up pics and the answers to these questions?
With all the pics you have in your archives, there have been plenty to answer lots of questions over the years.

I know they're around here somewhere, but I haven't noticed any recently. Should have some on the computer, but you know how that goes.

Anyway, factory brackets are identical-ish in shape and size, with the frame mount having two holes (for the two long bolts) and the draglink mount having four (for the two u-bolts).
In each case the 90° section with the large hole for the shock bushings is facing "outward" so that the distance between the two mounting points is at the maximum available distance.
The frame mount location is set (unless you have one of the rare-ish models with no holes?) and the draglink end is set if you have a stock draglink with the welded-on locating brace to keep the shock bracket from sliding on the round rod.
If a dropped pitman arm is used you will have to decide whether to leave the shock at the odd and ugly angle, or make a spacer to go between the frame bracket and cross-member.
If using non-stock linkage, sizing is based on the length of the shock and where it's compressed all the way when the wheels are turned right, and extended all the way when the wheels are turned left. As long as it does not bind up in either direction, you're good to go.

Pics will still be good if someone has any, but that might be enough to get you started.

Paul

DirtDonk · Aug 5, 2021

Shimmy just posted up some pics of the Duff brackets here: https://classicbroncos.com/forums/showthread.php?t=311487
Not exactly the same, but mount the same as stock so you should be able to dial yours in with those pics.

Paul

Rustytruck · Aug 5, 2021

death wobble comes from the tires and unbalanced centrifugal force. then it manifests its self on the components least able to control those forces. when everything is new , tight, and properly adjusted the system can handle minor imbalance. the weakest link is the trac bar, its bushings, and the relationship between the mounting bolts and the mounts. if the bolt and holes are not tight they must be repaired. usually using welding weld washers to the trac bar mount is a common way. at some point you have to lay under the suspension and look at each steering connection and track bar connection and see what is loose or not moving properly while someone in the cab rocks the steering right and left. not trying to turn the wheel but just bump to bump. anything loose in the linkage must be repaired.tires on the ground with full weight on them. The next thing jack up the front end and but a bar under the tire and lift that bar up and down to feel for looseness in the tire assembly. if there is looseness check the wheel bearings and ball joints and /or kingpins depending on what axle you have. but remember it all starts at the tire assembly if out of round bent out of balance or not enough toe in you have a real challenge ahead of you if those are not proper first. run your hand over the tire is it wavy? is it worn uneven then the tire is very suspect. you can swap tires from front to rear and see if anything improves if it does then you know its tires.

904Bronco · Aug 5, 2021

DirtDonk said:
Shimmy just posted up some pics of the Duff brackets here: https://classicbroncos.com/forums/showthread.php?t=311487
Not exactly the same, but mount the same as stock so you should be able to dial yours in with those pics.

Paul

My 69 Project, Mater, is just a little twitchy on our poor road quality here in the South bay Paul. He runs down the freeway at 75 and zips down the road just fine on a fresh road surface with his new 33's. Since none of us Californian's really know where the extra gas tax we pay goes anymore, supposed to be for the roadways, I am just looking for a way to smooth things out. Since I have only run a steering stabilizing on one of my rigs in 20 yrs, I needed a pic to see how things were set up...

Yes, he has a drop pitman arm, fresh steering components and bushings, rebuilt PS box, rebuilt D30, and an adjustable track arm. So I don't see any play. Played with tire pressures some... Steering center link is near parallel, so The road surface quality seems to be the wildcard here.

Doug

Rustytruck · Aug 5, 2021

want to know where road tax goes in california it goes on high40 from barstow to the state line where they are grading and updating drain culverts in the center median in the desert that gets no rain fall. must have been a billion dollar investment going no where. there in needles now. a 2 + year investment flushed down the toilet unless Noah was running the operation.

savage · Aug 5, 2021

DirtDonk said:
Shimmy just posted up some pics of the Duff brackets here: https://classicbroncos.com/forums/showthread.php?t=311487
Not exactly the same, but mount the same as stock so you should be able to dial yours in with those pics.

Paul

That was my thread, mine use to be in stock location, but with the new T-REX arms, I had to move it to the passenger side, but here is a video that shows how he figured the location (https://www.youtube.com/watch?v=RGQ00T-YCzI)

904Bronco · Aug 5, 2021

savage said:
That was my thread, mine use to be in stock location, but with the new T-REX arms, I had to move it to the passenger side, but here is a video that shows how he figured the location (https://www.youtube.com/watch?v=RGQ00T-YCzI)

Thanks, still running stock arms...

EODMike · Aug 11, 2021

m_m70 said:
sounds like you have more of a wandering problem than a wobble.

also, looks like you "set this up" a year ago (assuming added a lift/suspension kit) but only now driving it at highway speeds (last couple months) so this might not be a "new" thing.

If you can post some pics of the front suspension head on that shows the tie rods and drag link so we can see the angles.

also, if you got an alignment done post those up as well. it's good to see what your caster and toe in is

I run 33 x 12.5 at 26 to 28 in front and 26 in the rear. anything over that it just feels squirrely.

Sorry for the delay, I have been laid up sick and threw out my back. I did become a contributor though so I could post some pics. I hope these captured what you were looking for. Thanks.

reamer · Aug 11, 2021

The angles look good, the drag and track bar are "parallel as required, and the grease zirk is facing up.
What you have is either bad Toe-In values, Very easy fix, Or zero-to-no Caster (a real BITCH to correct).
If you never use the front end for off-road then 7 degree C-bushing will give you caster, BUT screws up the driveshaft-to-pinion angle.
To do this right you need to have the welds holding the steering knuckles to the axle tube ground off and the knuckles rotated on the tube @1/8 to 1/4 inch and rewelded.
Dana, for some reason assembled all of these with zero to 1 degree caster......

DirtDonk · Aug 11, 2021

Listen to reamer and maybe fiddle with your toe-in settings, but certainly verify your other settings as well. Never hurts to know what you're dealing with.
But you might also now be feeling that vague steering feel that comes to some Broncos (but apparently not all) when you have a borderline lift height (in your case 2.5") but have not added any steering corrective factors yet. Such as a trackbar drop bracket and dropped pitman arm.
The old school (back when nobody cared about such things) feeling was that you did not need those until you were at 3" of lift or above. Well, you're pretty darn close to that now!
When I look at your pics (yes, they help a great deal!) I see "decent" angles, but angles that I feel are nevertheless still too steep.

So while you might still fiddle with other stuff, if you want the most linear feeling to your steering out on the road, you would do well to add the drops (both of them, and NOT one or the other) to get your angles back to near stock.
As said, the old school feel was that it was just a truck and who cares how it handles on the street. It's an off-roader after all...
I figure that at only 1-2 inches of lift you can still get away without them. But at 2.5 and above you might as well do it.

See how easy it is for me to spend more of your money!?%)

Paul

reamer · Aug 11, 2021

I'm in the same boat(s) Paul,.. 2.5" of lift, with no caster (Might get the drop bracket and drop pitman) but need to pull the front end and adjust the knuckles, And the Other boat I'm in, with plenty of others is , My 2021 Bronco is MIA.....

helo-mech · Aug 11, 2021

The tie-rod centerlink (grease zirk) might be a little less angled than what is needed. Mine initially was set parallel and was causing all kinds of "wandering." I gradually adjusted the angle upwards until I got all the 'wandering' out. It took maybe three adjustments up (basically pointing at the radiator) for mine to find that perfect spot. I could not believe the effect that one tie rod had on my handling.

Take a look at post 10, 12, 18 and 27 in this link.
https://classicbroncos.com/forums/showthread.php?t=278348

Steering wobble

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