when i hit 40 mph my truck starts making like a humming grinding noise. i have a little bit of shaking in my floorboard and when i start to slow down my steering wheel shakes a little i don't know if those 2 things have anything to do with the noise but they might to me it sounds like maybe something with an engine component but my friend who know some about cars said it sounds like something is rubbing. if anyone has any ideas i would appreciate it.