i have a 98 f150 SC 4X4... i have had a slight vibration for quite some time but seems to becoming more noticeable... in the floorboard/pedals/steering wheel... basically everywhere... at certain speeds it is worse than others... mostly felt while keeping a steady speed around 50Km and also at about 110Km... it is also amplified when i press the brakes which leads me to believe it is a warped rotor... i have heard that a bad enough rotor will "bump" the pads causing a small constant vibration that is worse when brakes are applied... can this be possible?... if a rotor was that bad wouldn't it cause my truck to pull to one side?... it goes perfectly straight down the highway for a long ways.

also, perhaps unrelated... O/D light began flashing after 80Km/hr... had it checked and code states that it is the VSS... my speedometer does not seem to be correct because of this.

 

You may have a belt seperating in one of your front tires or a cupped tire causing it to vibrate. Run your hands over your tire tread to search for cupping. Good luck.

 

Get the tires balanced, check your u-joints too. Rotors? not likely.

 

u-joints have been replaced... one was bad but didn't change vibrations... what is meant by cupping? like "bubbles" or "blisters"?