I have a 2000 F350 Super Duty Crew Cab with 90,000 miles on it and it has developed a front-end vibration SOMETIMES! I can drive this truck at 70-75 miles per hour and it will be as smooth as smooth can be and then all of a sudden it will start vibrating and then it will quit. I had the front-end checked a couple of months ago and was told by my trusted mechanic that the front-end was fine. Has anyone else experienced this particular problem and if so, did you find out what was the cause?

Ron