This is strange... I have had a vibration since I replaced the tranny, balanced tires etc. Finally had my son Tom at Pauls Auto drive the car and he said driveshaft, when we pulled it we found this... Wierd I know it wasn't that way when I installed it??
http://popsfun.com/images/extra_stuff/dsriveshaft1.jpg
http://popsfun.com/images/extra_stuff/dsriveshaft2.jpg
http://popsfun.com/images/extra_stuff/dsriveshaft1.jpg
http://popsfun.com/images/extra_stuff/dsriveshaft2.jpg