I don't think this is a death wobble issue but correct me if I'm wrong. My complaint is that when I hit a bump in the road, even a not so particularly rough road to bridge transfer, square with the front end my steering goes goofy, this is more evident as you carry more speed. By goofy I mean that the steering will become light, unpredictabilly jerk left and right and give you an unsettling feeling.
The truck is a 2013 CCLB 4wd F350, FX4 with stock tires ( for now ), 16000miles and a 2.5 spacer on the springs with a shock spacer.
This driving characteristic was evident before installing the leveling kit, something else I've noticed that may or may not be relevant is that when towing heavy (44', triple axle, enclosed, GN, w/two 2,400# race cars) the truck has a bad shudder when turning while accelerating but that feels more like driveline shudder.
I would almost describe the bump issue as a bump steer problem, or a bad shock characteristic? I'm not sure, because I've added the leveling kit I don't really want to take it back out just so Ford can diagnose it but if need be I might if it's something more serious. Do y'all feel like I should get an alignment and shocks or talk to Ford first and see what they want to do?
If it matters the gooseneck is factory.

 

I had similar issues previously and found it related to my tire pressures being too high, front end alignment off a small amount, and poor stock shocks. I had my alignment corrected, I put my front tires at 65 psi and rears at 70, and changed my factory shocks to good aftermarket ones. Each of these made improvements to the way the truck handled, and once all were done, it drives very well. No more sudden lane changes when hitting rough pavement.

 

I just had my track bar bushing/joint replaced. It shimmied like crazy when hitting bumps. Steered odd too.

 

Did you correct the caster for this change to the front suspension and get it aligned? If you just threw in spacers the caster is likely zero and you will have problems. Caster is what gives stability.
http://en.wikipedia.org/wiki/Caster_angle

 

Nope, no caster corrections, how do we correct caster on these trucks? I don't think its adjustable?
Tire pressure is 65 all the way around, thoughts? I'm tempted to buy shocks after reading all the threads about how much the ranchos suck.

 

I ended up having a shop install adjustable caster bushings to correct my steering after installing a 4" lift. The stock shocks are actually Rancho "branded" shocks, the true Rancho shocks are great, no comparison to stock. I have Fox 2.0 shocks that I installed with the lift.

 

small caster changes can be made with ball joint sleeves which is how ford aligned the truck from the factory. The largest sleeve can only correct for about 1" of lift.
here are the options:
- radius arm drop brackets from 3.5" lift (ebay)
- aftermarket radius arms
- modify the factory radius arms
- ball joint sleeves (I don't recommended)


New/different shocks will not solve geometry issues. At some point you should upgrade shocks, however I would address the caster issue first.