Tranny causing vibrations?

[12Pack]

Thinking about picking up this 91 gt only thing wrong with it "so the seller says" the tranny will need to be replaced as it causes vibrations at high speeds, but drives and shifts fine. I asked if it was a mount and he said he replaced the motor mounts and tranny mounts. What would cause a tranny to vibrate?

 

[2000xp8]

More than likely it's the driveshaft. You will need a Ford racing aluminum shaft.
Don't tell the seller that though.

 

[Mustang5L5]

Could be bad output bushings on the trans. $20 part...a little bit of work to change.

Could be driveshaft too

 

[jka]

It may not even be the drivetrain.... but the harmonic balancer... i had the same vibration and i replaced u-joints and mounts but it turn out to be the balancer.

 

[2000xp8]

It may not even be the drivetrain.... but the harmonic balancer... i had the same vibration and i replaced u-joints and mounts but it turn out to be the balancer.

A bad balancer vibrates regardless if you are driving or not, it's rpm based, not speed based.