mustang vibration

Does anybody have a mustang with a vibration? Mine(2004 v/6 anniversary eddition) has a vibration(roar) at 25 thru 30 mph and dissapears after that. Road speed is smooth as silk. I replaced the driveshaft with u joints and motor supports but no change. I can't take it in because of no warranty ( wrecked and fixed). It has 800 miles on it now. It holds the road perfectly and drives great but the vibration is bugging me.

Wrecked and fixed? humm, let me guess, front end got hit?

Yes, it was hit in front of the right front wheel sideways. The vibration lessons when the throttle lets up and stops when put in neutral at 25mph

Could be a few different things. A bent motor mount or tranny mount among others. Something got tweeked in the crash and is not straight. If you had a shop do the repair, I would bring it back.

Hmm alot of possibilities. Did you have the frame straightened? If it goes away when you take it out of gear that means there is no force going to the rearend. Are we sure its the front end giving the vibration? But I would check motor mounts and tranny mounts like HiFlow said.

I had the core support and aprons replaced. I found the left motor mount bent and I replaced it. I took all mounts out again and examined them but they look new. I have tryed sighting to see if the motor is straight and it seems to be. It may be my imagination but it doesn't vibrate near as bad now. I wish I knew what made the difference. Thanks for all the help.

If your thrust is way off your trans-diff may be in a bind or too steep of an angle. But that would take a hard hit and alot of warping.