Hello, my 02 trailblazer LT has recently started to shake when I reach speeds of 60 mph and higher. I never felt this before until about a week ago, after I had the brake pads changed. From 0-60mph, it is a smooth ride, but when it reaches 60mph, you can clearly feel the shake from beneath...it feels like it is coming from the front of the vehicle. When I turn the wheel (like changing lanes or going around a curve) at speed, the shake gets little worse. Any ideas? Thank you.