I hope someone can help me here. My car vibrates heavily at 150-160 km. Faster or slower than that it is smooth. Engine mounts, transmission mount and flex discs(both front and rear) are replaced with original parts from the dealer. Checked the tire balances(tires were also replaced in middle september with michelin primacy 3). When I changed the flex discs I took the drive shaft off the car to check the middle bearing;but as a single piece, did not seperate the back and the front side; however I did not mark the original connection points on the shaft and transmission/differential. I just replaced the flex disc and fastened the bolts. Will that be the cause of vibration?