Re: Driveshaft Vibration Dampener

The disc serves two purposes that I know of. It damps vibration. But
it also takes care of any misalignment between the tranny output shaft
and the driveshaft just like a universal or CV joint would do. In
theory there would be no misalignment. But that would be assuming that
all motor mounts, transmission mounts, shaft carrier bu****ng
mounts(not the real name, but the thing that holds the driveshaft at
the center of the car whose name I can't remember.), etc. are not worn
or even slightly misaligned. Without this, once your motor mounts or
transmission mounts start to sag, the bearings sup****ting the output
shaft of the tranny won't be subjected to extra forces.

I'd find another shop with more knowledge. It's often a good indicator
of competence.