The new owner of our 1971 MM combination car has posted on Facebook pages that the car has developed a vibration during acceleration. He has had brake work done, driveshaft balanced with new universal joints installed. They have located a broken motor mount which they are in the process of correcting. Others have suggested carrier bearing or torq converter as possible causes. We had no indication that there were issues when we sold the car and are trying to help the new owner make repairs so he can enjoy the car. Any help I'm sure would be appreciated. Thank you.