Why does my truck shake/rattle when I hit 50-55 MPH but when I hit 60 it goes away

Hi, this is Bo, an auto expert on RepairPal's Car Genius team! Is it shaking, rattling, and rolling?!? Maybe we should rename the Sierra The Comets? Great. Now, that song will be stuck in my head all day. The shaking or rattling you're experiencing could be due to tire balance issues or worn suspension components. At that speed range, small imbalances or wear can cause noticeable vibrations. Once you exceed 60 MPH, the centrifugal force may temporarily smooth out these vibrations. Have your tires balanced, and check your suspension components, like ball joints and tie rods or sway bar links, for wear? A mechanic can pinpoint the exact cause and ensure a smooth ride at all speeds. If you have any other questions, please call us at 877-913-1554! We'll gladly find you a certified RepairPal shop in your area!