Thank you from northern maine but here's the thing never had that vibration with the old shaft but i didnt replace the coupler on the engine side? The front one looked fine?the rear didnt look bad u could see were he old shaft wore a ring in it?You need to give alot more information than that if you want help or answers.
When does it vibrate, at idle or while moving?
Is it consistent all the time?
Does it change in pitch/severity?
Do you only feel it in your feet, or other places?
Any more information you can provide.