Another Death Wobble

[the74bronco]

Looking for some advise. I have some pretty sever death wobble if I hit a bump or washboards between 25-35mph. It feels like my tires are going to come off and will not stop until I stop or get to under 5mph. I have read a ton of the threads, but I am not familiar enough to see if I have the angle issues many talk about.

1974 bronco 5.5” duff lift with 37x12.50r17

I have replaced:

-duff lift with new coils, rear leaf, and front duff shocks.
-cut and turned the Dana 44 for caster
-new ball joints
-new trac bar/bushings
-new toms psc steering box
-on second set of tires (30psi front/rear)

Is drag link the culprit? Does the angle look good? It does make contact with my trac bar castle nut at full turn, but I don’t thing that is causing my death wobble. Looks like I might have a tiny bit of play in my trac bar at full crank.

https://flic.kr/p/2rjoLfy
https://flic.kr/p/2rjpZJt
https://flic.kr/p/2rjoLfJ
https://flic.kr/p/2rjqt9p

 

[Shimmy]

i'll let others weigh in but IMO that drag link angle is pretty steep. that angle alone would contribute to some bump steer.

 

[the74bronco]

i'll let others weigh in but IMO that drag link angle is pretty steep. that angle alone would contribute to some bump steer.

Do most switch the steering to over the knuckle for 5.5” lifts?

 

[Shimmy]

Do most switch the steering to over the knuckle for 5.5” lifts?

definitely! i'm at 3.5" and OTK

 

[Broncobowsher]

I want to see more the the track bar mount on the frame. Looks like a drop. Bolted or welded? Is the frame cracked (pretty common with a drop bracket)?

 

[73azbronco]

Track bar is obviously moving when you start to turn, looks like frame side, look there.

Second those are pretty severe angles, need either dropped or raised track bar mount, I think. But fix movement of the bar first.

 

[the74bronco]

No cause you’re in

I want to see more the the track bar mount on the frame. Looks like a drop. Bolted or welded? Is the frame cracked (pretty common with a drop bracket)?

https://flic.kr/p/2rjke6m
https://flic.kr/p/2rjqyYd
It is both welded and bolted. I looked pretty close with a light and I didn’t see any cracks.

 

[the74bronco]

Track bar is obviously moving when you start to turn, looks like frame side, look there.

Second those are pretty severe angles, need either dropped or raised track bar mount, I think. But fix movement of the bar first.

I did notice when I turn all the way one way it moved, but it seems like the drop bracket is solid. It’s almost like I need to lengthen the bar a little. Is there a way to know how it should be adjusted?

I do have a pretty significant drop bracket. Should I add a riser on the axle end too?

 

[Shimmy]

to me it looks like the draglink is bending or the joint where the tie rod meets the drag link has slop in it? it could be that the drag link is flexing due to the severity of the angle

 

[the74bronco]

to me it looks like the draglink is bending or the joint where the tie rod meets the drag link has slop in it? it could be that the drag link is flexing due to the severity of the angle

Would that cause the death wobble? Is the T style a better option for the angle?

 

[ksagis]

Watching the video, when the steering box changes direction from pulling to pushing the drag link, I think I’m seeing the tie rod between the knuckles bend up and down.

Do others see that?

Edit: I just watched the video again, the link between the knuckles is def banana-ing up and down when the drag link pulls or pushes on it.

 

[ksagis]

@Shimmy, seems to me that sources of bump steer and death wobble aren’t super linked. Death wobble is often slop, bump steer is bad geometry

 

[the74bronco]

Watching the video, when the steering box changes direction from pulling to pushing the drag link, I think I’m seeing the tie rod between the knuckles bend up and down.

Do others see that?

Edit: I just watched the video again, the link between the knuckles is def banana-ing up and down when the drag link pulls or pushes on it.

Is this due to the drag link lifting the tie rod up? Do I need to switch to one of the heavy duty steering setups or would knuckle over fix the issue?

 

[ksagis]

Like Shimmy said, the steepness of angle is contributing so TRO would help but beefier parts would too. I bet your tire size is contributing and maybe you have a fair bit of offset in your wheels which would contribute too.

I’ve never noticed something like this myself, hopefully others with deeper knowledge will chime in.

You could try partially jacking the tires to relieve friction and see if the bending goes away.

 

[73azbronco]

use camera close up and move steering while filming the upper drop link area.

 

[Broncobowsher]

use camera close up and move steering while filming the upper drop link area.

I'm suspecting that as well. Can't point to anything at the moment.
Also a video clip not lock to lock. Just a quarter turn side to side (like the wobble). and you can be fairly quick about it. Looking for stuff moving, slightly, in bad ways.

 

[Oldtimer]

And mount camera on bumper, not floor of shop. It will eliminate motion of whole Bronco on tires, and only show relative motion of steering components to frame.

 

[73azbronco]

I'm suspecting that as well. Can't point to anything at the moment.
Also a video clip not lock to lock. Just a quarter turn side to side (like the wobble). and you can be fairly quick about it. Looking for stuff moving, slightly, in bad ways.

actually locklk to lock as well, even if it does not move with little movement, if it moves at lock it is not right.

 

[joebronco73]

Watching the video, when the steering box changes direction from pulling to pushing the drag link, I think I’m seeing the tie rod between the knuckles bend up and down.

Do others see that?

Edit: I just watched the video again, the link between the knuckles is def banana-ing up and down when the drag link pulls or pushes on it.

Absolutely. There is flex in the tie rod.

I did notice when I turn all the way one way it moved, but it seems like the drop bracket is solid. It’s almost like I need to lengthen the bar a little. Is there a way to know how it should be adjusted?

I do have a pretty significant drop bracket. Should I add a riser on the axle end too?

In my experience, drop brackets are very limited to stock/shorter suspensions. I've seen Super Duty frames twist with long enough drop brackets (increase in moment arm). An axle riser is definitely a better way to go when you start getting into taller lifts and larger tires.

*add: you may want to consider a TRO (tie rod over) setup, with a more substantial tie rod kit (check out the James Duff Heim Joint Kit)

 

[desertoasis2b]

double check your upper ball joints preload adjusting sleeves , i had one loose on the passenger side and thats what was causing my death wobble