The car shakes when it goes above 50 MPH
Car shaking on 2005 Chevrolet Equinox
It sounds to me either a weight came off of a wheel or bent rim it could possibly be a bearing on one of the hubs jack the car up and try to (wiggle) each wheel to check for play! But more than likely you just need to get your wheels balanced! I have had a weight come off before it happens from time to time! Good luck hopefully it's just a wheel weight!
Sounds like you may have a wheel balance problem. Have your tires checked and wheels checked for proper balancing.