So I have a vibration problem and I was wondering if anyone had any ideas of what it might be. When driving on the highway and I reach a speed of 100Km or 60mph to 120Km to 70 mph in that range I get a vibration, once I get over 120km then the truck drives smooth, but once I come down to the 100Km range it is vibrating, I notice it especially when I take my foot off the gas pedal. I have just replaced my rotors and pads to see if that would help and it has not. Anybody have any ideas?

Thanks

 

Could be exhaust.