It sounds like it is coming from the driver or passenger door or window area. It only happens at wind speeds greater that 70 MPH, ie 55 MPH vehicle speed with a 20 MPH head wind. It goes away when we get behind a semi. It was intermittent at 20K mile but appears to be constant at high speeds now (29K miles).
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2009 Ford F-350 Super Duty Question: I have a loud cabin buzzing at high speeds what could this be?
POSS DOOR WINDOW SEAL IS TWISTED OR CRACKED.INSP FOR DEFECTS