i got this truck last friday so a week ago and i drove it a hundred miles to home and it didnt make the noise im hearing now. i did go play in the mud and im pretty sure that is the culpret but the noise is a constant humming coming from underneath the bronco i can feel it in my gas petal. but it only happens when i am exelerating over about 35 mph. if nyone has any ideas on what it would be let me know asap. Thanks