I have a 2011 F550, 6.7. runs great, looks good, just turned 61k, tires need to be replaced, (working on that) The OEM suspension seems intact, had to replace the OEM steering damper, may have an alignment issue, maybe the tires since they are worn out abit, the balance may need attn, will wait for the new tires for that. THE PROBLEM RIGHT NOW: I have the worse death wobble on the planet. Oh no, it not only shakes, it is left and right, up and down shaking, the whole front end shutters like Im going over close knit speed bumps.. It oscillates so bad, I have to hit the brakes to disable the shuttering. it occurs on the interstates mostly at speed, 55-65mph, most of the time, truck tracks straight, no pulling, no out of balance vibration or shake when just driving the truck. it is scary to say the least, the shakes occur when the road has certain types of bumps, or expansion joints in the road. Now, Im thinking bad track bar-OEM, alignment out for sure, wheels out of balance. Let me say this, the steering wheel is not positioned straight up and down, it was positioned at the 4 o'clock position, after this past Sunday morning shake, its now 2 o'clock. Im so fed up with this Not so Ford tough truck, Im now looking to get another Not ford product. any suggestions?? BTW all, I have new tires rdy to go on, alignment scheduled, dual steering stabilizers from Rancho,-hopefully they will fit, looks close, they may fit, new sway bar bushings that are even fitted with zerk grease nipples.