What's the function of the weight mounted on the tailshaft?

[oldcarnut]

I've seen 727's with and without them.  It's a C shaped heavy piece attached to the tailshaft.  What's it for--vibration maybe?    The tranny I pulled from the C-Body had it on it but I wasn't able to find a reference to it already posted.  Was going to post a pic but the camera batterys were dead.

[cdr]

you would be correct ,harmonics,vibration

[oldcarnut]

Thanks,  was just wondering if I should put it back on since it's now in an E Body

[Nacho-RT74]

I'm trying to get one to my Charger

[MrSnicks]

Rotational balancing purposes. On these 40+ year old cars if you pull the driveshaft to replace the u-joints I'd take it somewhere and have the driveshaft checked for balance.

Patrick

[ACUDANUT]

They are not necessary if you have the driveshaft balanced.