MikeinMissouri

I have a worsening vibration coming from front of car. Starts being noticeable at about 30 mph, especially negotiating a curve. Dealer says they can't find anything wrong. They changed the front brakes, and have rotated tires, but the noise is still there. Sounds like a whump-whump-whump that speeds up as the car accelerates. Any help would be extremely appreciated. The car had 152,500 miles on it, and had only been maintained by Toyota dealer. Thanks in advance. Mike