I know this has been discussed by many here. I have ready many threads and watched numerous videos. I'm at my wits' end trying to solve this problem. Truck has 207K miles. I have replaced all steering components with Ford/Motorcraft parts. Tjhere is no perceptible play in any of the joints. Bilstein shocks front and rear, and steering stabilizer. +2.5'ish degree corrective caster bushings (which seemed to help the most). Alignment has been checked numerous times.

Current settings:
Left Camber: 0.0
Right Camber: -0.5

Left Caster: +3.1
Right Caster: +4.2

Left Toe: +.04
Right Toe: +.03
Total Toe: +.07

Steer Ahead: 0.0

I recently made a trip to Houston, TX where the DW occurred several times when transitioning from bridges back to pavement or just hitting rough spots in the pavement. Every time, speed has been at or above 70MPH. When I arrived at my location, I swapped the tires front to rear. On the trip home the truck made almost the entire trip home before occurring once. The tires do have approximately 50K miles on them. Michelin LTX A/T 2.

Is it possible the tires could be the culprit?

Does anyone have experience with MICHELIN AGILIS CROSSCLIMATE? They appear to have a slightly less aggressive tread pattern than the LTX A/T 2.

Am I overlooking something here? For reference, I perform my own alignments on my race car and other classic car. I understand that additional caster increases stability...especially at higher speeds. Is that the case here...does it just need more caster?

 

I’ve never seen a particular tire brand cause death wobble, but on my 07 I could get it to wobble by lowering the front tire pressure below 50 PSI.

 

Tire pressures was also a believed source of error. However, I checked them and they were all equal at 80psi.

 

I think it might be a case of the most obvious is the likely culprit. You said more caster helped. It's likely that another degree or two would get you there.

However I do recall reading of some Michelins causing DW unless inflated to the max. With 50k on the tires you wouldn't be replacing prematurely.

I've had no DW with Cooper AT3's (although I argue you should view them as an HT because they suck in dirt and snowy roads) or BFG AT's

 

Thank you Sir...I'll take a look at those tires as well.

Does anyone make a higher degree of caster bushing? I have done some searching and didn't really see anything higher than what I have. I thought I had seen some higher before installing the ones I have, but have been unable to find them again.

 

I read you've changed all steering parts, but just to double check, did you replace the track bar ball joint and the track bar bushing or the entire track bar? I had an issue with mine and I resolved with replacing the track bar bushing (had a tear in it, seen when moving steering left to right quickly) and the track bar ball joint, I used Motorcraft parts as well.

I run 65 psi front and 80 rear, only when towing heavy, otherwise 65/65 and that PSI has not caused any issues for me. I've got same tires as you, 20" and I'm on my third set.

 

curious as to why the 80psi. the door jam on my 16 f250 is only 65 front and rear. have seen some people complain about DW with higher front pressure. otherwise sounds like you have replaced the main culprits being tie rod ends, track bar joint/bushing, steering box and shocks. were any of the bolt holes wallowed out? i have seen people have issues with tires causing it due to being improperly balanced. I have also seen people have issues with warped rotors and stocking calibers causing dw feeling.

 

I was going to say this, too, but I ASSumed the OP was dealing with the Michelins I've heard of which allegedly seem to cause DW unless fully inflated. I agree it seems to not make a lot of sense otherwise.

As for everything else, I was also going to ask about track bar but because in his first post OP said "all other joints are tight" or something along those lines, I again ASSumed he knew what he was talking about and had thoroughly checked the track/panhard. Perhaps not.

OP: I don't know much about bushings. BD Diesel at least used to sell a kit to physically lower the FCA mounting points, thus rolling the axle back. I've always said if I needed more caster on my '11 I'd find a way to do this (but metalwork/fabrication is what I do). It's not rocket science, but certainly does involve some specialty tools not everyone cares to invest in.

 

I replaced the complete trackbar. I have checked all the other joints multiple times, but not within the last six months. I suppose it is time to repeat that.

I agree on what the door jamb states for tire pressures and 65psi is what they originally had. However, when I first started this adventure and thought it was ONLY an alignment issue, the local Firestone dealer (which is the only place with a rack large enough for Super Duty's) said I need to increase the tire pressures to 80psi...so they did. It did seem to help.

I did think about lowering the tire pressures 5-10psi since I have now replaced the steering components.

 

He talks forever -- although the theory/practice lesson can be worthwhile-- then around 6:00 he actually gets under the truck to show some cool stuff. Also I believe this was an '05-07 and I'm not certain if '08-16 changed anything with FCA's or front suspension?

 

I rarely run over 60-65 in my front tires unless towing heavy, and even then I'm not sure I've ever exceeded 70. But, I've got the 6.2 which has gotta be lighter than a 6.7

 

I have seen that video. Speaking at least for the '15 trucks, the caster bushings are in the lower spindle mount. It's a fairly simple job.

 

They're ball joint bushings, no? With a unit bearing you don't really have a spindle per se. Ball joints mount your knuckle.

They used to make spindle shims to adjust camber on old school live axles.

Regardless, it seems you have all the info you need. So, go forth and do. Or don't.

 

I may have used the incorrect terminology...these guys:

 

Replaced the track bar and track bar ball joint yesterday. They were the only two items I didn’t replace a few months back. Hoping to decide on tires this week. And hoping those changes finally resolve my truck’s excessive DW. I will say the ball joint and the track bar bushing were worn slap out at 205K miles.