At about what speed would a drive shaft out of phase start to show up? I have a 31 model A that the car starts shaking at about 57 MPH and mostly goes away at 65 MPH. Could a drive shaft act like that or would it just get worse as speed goes up? The car has a 2.3, T5 and 9 inch ford rear. The shaft is a little less than 36 " in length. The shaft was balanced but it is offset 1 1/2 inch to the side. It not a new problem has been like this since I built it.