Re: F350 Dually Vibration Issue
The dealership is stumped. My 2014 F-350 Dually two wheel drive has developed a body vibration as the truck hits 60 mph and increases as the speed goes up, but if speed is held even the vibration will come and go. It's not the death wobble. The dealership has ruled out front end, wheels, tires, rotors, and drive shaft/line They are asking Ford engineering for help. No accidents, bumps, hard breaking, etc. Has anyone experienced anything like this. I have 17K miles on the truck. I don't know if the vibration occurs while towing It developed on a trip to MO and has gotten slightly worse. I wonder what happens if Ford cannot find the problem? I have full faith in the dealership--I've been buying cars from them for 17 years and the service manager was my next door neighbor for many of them--one of the few people I would trust with anything I own.
Question for both you and Malcom, do you feel the vibration in the steering wheel or in the floor/body? If in the steering, then look to the front end. If in the floor, then you'll have to search further. You said it occurred suddenly during a trip. Do you remember anything happening prior to the vibration, hitting a pothole, curb, etc. Did it come on suddenly or grow over time? Did you put a lift kit on or change anything before or after your trip?
Drive line angle can cause vibration, as can incorrect drive line timing, and bad universal joints, but you said they changed out the drive line so I'm assuming they checked that.
You said they changed out rims and tires, did they check the rotors? An out of balance rotor will cause vibration especially as it wears. Wheel/axle bearings could also be a culprit. Especially the rear, since you indicated it was worse when loaded.
Is it possible the vibration you are experiencing is caused by the engine? Torsional vibrations tend to peak at certain speeds. I've seen/heard of bad harmonic dampers. Bad motor mounts can also cause it.
Since you indicate that the vibration is worse during towing, there's a possibility it's differential related. If the newer Fords are like mine, they use a collapsing spacer to set the preload on the pinion bearing. An incorrect preload will cause vibration. Also bad bearings, incorrect preload, improper adjustment, or bad gears in the differential can and do cause vibrations. There is also a possibility of something wrong in the tailshaft off the transmission.
Unfortunately it is something that even an experienced mechanic will have to track down step by step. Sounds like they've already checked the most obvious.