Death Wobble

[divemaster5734]

The test drive was cut short when I got a really bad wobble at around 45-50.
I immediately assumed tires, so pulled them off and cleaned all the debris that had accumulated during the 13 years it sat.
Took it out and same.
I searched the forum and realized the driveshafts could cause this.
Since I went from e4od to zf5 I used the donor truck's front axle.
There's only one way it can mount.
I had the rear driveshaft made at a guy that was recommended by several transmission shops.
Going through some threads I realized there may be a certain orientation for the rear shaft?
It's a one piece, and the guy only needed a washer to balance, which I put at the 3rd member.
I didn't have the wobble before, but again, that was a long time ago.
The sway bar links are visibly rotted through, which I plan on replacing when I put in the '03 axles that are next on the agenda.
It's a new PS pump.
I didn't want to spend any money on the existing steering, as I'm saving and researching everything I'm going to need for the axle swaps, but was hoping to be able to drive it a little to shake the bugs out of everything else.
Am heading out there later today, and hoping for some inspection tips to diagnose.
Thanks

 

[u2slow]

Death wobble is usually a caster issue, compounded by other worn parts. A steering stabilizer can sometimes work as a short-term bandaid.

If you are going to swap in a newer axle, you'll be doing some suspension mods regardless, so you can add some more caster at the same time.

 

[divemaster5734]

Death wobble is usually a caster issue, compounded by other worn parts. A steering stabilizer can sometimes work as a short-term bandaid.

If you are going to swap in a newer axle, you'll be doing some suspension mods regardless, so you can add some more caster at the same time.

I'm a newb armed with factory service manuals, it just takes me a little longer to undertake the learning curve for every minute facet of every dang thing.
Still figuring out what's needed, what updates are available, and where to procure the parts.
That said, I pretty much figured it was in the steering.
Heading out in a minute to check the wheel bearings, but those usually manifest issues differently.

 

[u2slow]

What year is the truck and axle?

Kingpin axles are perhaps more subject to death wobble because the upper trunnions are not fixed, but rather spring-loaded. So when things start moving just a little bit funny, things can escalate. If you replace the axle with an '03.... no more kingpins.

Worn anti-sway bar stuff may cause some occasional noise, but not death wobble.

 

[Kdo58]

Lift the front wheels off the ground, and have someone turn the steering wheel back and forth, and see whats loose or worn out.

 

[divemaster5734]

What year is the truck and axle?

Kingpin axles are perhaps more subject to death wobble because the upper trunnions are not fixed, but rather spring-loaded. So when things start moving just a little bit funny, things can escalate. If you replace the axle with an '03.... no more kingpins.

Worn anti-sway bar stuff may cause some occasional noise, but not death wobble.

'89 F350 Crew short box. Dana 60..
Putting a '03 super duty set in.
D60.

 

[u2slow]

The 03 axle has 1" wider perch spacing, so it's not bolt-in. With a proper kit, healthy springs, and tight balljoints I'm sure you'll swap out your DW problem.

 

[Rdnck84_03]

I immediately assumed tires, so pulled them off and cleaned all the debris that had accumulated during the 13 years it sat

If I am understanding what you just said correctly, and your tires are 13+ years old. That is definitely my bet.

James

 

[divemaster5734]

If I am understanding what you just said correctly, and your tires are 13+ years old. That is definitely my bet.

James

That's a possibility, but they had under 500 miles when it broke down.
Bought the truck and immediately put a 4" suspension kit and tires on it.
Only drove it a handful of times locally and then had the engine fire.
The tread and sidewalls appear to be in good shape, and there was still 20lbs of pressure when I dug it out of the weeds.
Still, I agree, the tires are a possibility.
Am taking and sending measurements to CP Performance today to get sized for a axle swap kit with lift.
Will have to just sell the existing axles and lift.
Might as well add new tires to the new wheels while I'm at it.

 

[IDIBRONCO]

but they had under 500 miles when it broke down.

Low miles doesn't matter when they sit for a long time. The tires will still weather. I've seen first hand where some 400 miles tires were reused on a different car after sitting for 10+ years. He had one blow out while sitting in his dad's driveway, not moving.

 

[Nero]

Lot of shops won't touch a tire if its over 5 years old, and everyone recommends replacement after 10 years, regardless of wear.

 

[divemaster5734]

Makes sense, just a tough pill to swallow.
But then, it's a lot easier to deal with the tires on my timeline as compared to a blowout.
That could be catastrophic with those 35's.
Like the posture, but might just go stock elevation.
Would save having to install power running boards.
I modified some LED's to fit in the OEM running board slots.
They are white when the lights are on, which give excellent visibility, then blink amber when the turn signal is activated.
Spent some time disassembling some LED strips, soldering wires, and making brackets.
Didn't want to lose those.

 

[asmith]

Yeah tires are expensive, but if they have just been sitting a field for 10 years I wouldnt trust them on the highway with a load. That could lead to bad things. plus if you are swapping to newer Superduty axles you have to get new wheels anyway. I believe you have to run 17 inch rims at least to clear the brakes, but that may just be on the '05 and up.

 

[u2slow]

99-04 axles fit 16" wheels, but they are the metric bolt pattern.