You will have to get under the car to look at several things: 1: Something rubbing the driveshaft, E-brake cables, exhaust etc. 2: bad center driveshaft bearing or u-joint. 3: Bad engine/transmission mounts allowing enough movement for the driveshaft to come into contact with something. Good hunting, Mike 83 UrQ 84 4Kq 87 5Ktq 77 Ferrari 308 GT4