97 Formula auto 4:10 gears solid.tranny mount. Vibe started this summer after a long trip. Took driveshaft off cant tell if its out of balance. Its getting worse every time in drive.it. Really bad at tranny. If you put it in neutral going down highway its still felt but not.as bad. I'm thinking loose or.cracked.flywheel. Any other sujestions?

 

If you have the transmission in neutral the driveshaft will keep spinning ...
however the drive shaft could still be the problem I've seen on here that other members
have had to replace there drive shaft due to bad vibrations
I would think that the vibration from the drive shaft should stay the same in gear or not ???
maybe the motor mount's ?????
my car does the same thing its not that bad. ...but it is noticeable

 

Figured it out. Busted output shaft. Can move it all over the place and can hear a grinding inside tailshaft when I do.

 

Can you replace just the output shaft ?

 

Turned out to be a ripped poly tranny mount.

 

I thought you said you had a "solid.tranny mount" ???

 

Some call.it.poly. Some call it solid. Sorry. It was a poly mount. Was compleatly ripped one side.