I bought this car a year ago with 80,000 miles on it. I noticed right away a vibration when you approach 65 mph. It disappears around 73 mph. The dealer said it was probably due to two different size tires on the car and that they were a bit worn. I had them rotated faithfully until I bought new tires. There is still a vibration. I never expected a Cadillac to vibrate like that! Anyone have any idea what it might be??
Is it an ENGINE vibration? (Can you make it vibrate with the car standing still?) If you can’t, it’s in the driveline, usually a tire, sometimes a brake component, rarely a bent/deformed drive shaft. A shop that specializes in wheel, frame and axle service will sort it out quickly…