Vibration problem

[1996GT]

Ive had a vibration issue for a month now and I cant figure it out. At first I thought it was the tires/balancing. So I replaced the tires and balanced them, not the problem.
I changed the rear spacers also and still nothing. I also checked the driveshaft to make sure it wasnt rubbing or any obstruction, and that checked out fine. It starts around 25 mph and its mainly under acceleration. If I release the throttle it will still vibrate (slightly) but not as bad.
So now im stuck and dont know what to do next. Any suggestions?

 

[TACTICALGLOCK]

MAYBE A BENT AXLE OR A WHEEL BEARING.

 

[1996GT]

Well, today I was crusing at around 75 mph and the vibration got worst. Extremely loud noise coming from underneath the car and then.... snap one of my mufflers breaks off!! The only thing i can think of is the driveshaft some how was rubbing on it and snapped it. But i didnt see any marks or scrathes on the muffler or driveshaft so im gonna take it in to a shop.
This is the first time it sees a shop since ive had this 96. Oh well........

 

[bredman]

sounds like a good time to put some performance exhaust on

 

[1996GT]

Just to update on the vibration issue, it ended up being a few things. First, the u joints were shot. The trans mounts were toast. So this caused damage to the transmission tail shaft. I also need a new yoke and on top of all that the differential is going out. Not to mention the fluid it leaks cause of the tail shaft problems.
Talk about pouring when it rains huh.....

 

[Zwolaver21]

Damn, I am having the exact same problems. Same speeds and everything. I was thinking it was my front tires because I need some new ones. The tail of my trans has a slight leak but the mount is only a year old. I will have to give it a good look over. Thanks for your post.