[TR] tranny harmonic balancer?

[Gary Nafziger]

Reading the posts concerning crank harmonic balancer reminded me of a question
I wanted to ask the group concerning my tr-3 tranny.  It had a collar that
went around the tail end of the tranny and to it was attached a round piece of
steel (like a small ball approx. 3 inches in diameter) with a hole in the
center which had a bolt going through the ball and attached to the collar. 
The collar is attached tight to the tail of the transmission (I assume) but
this still allows the ball to rotate.

My question is:  Am I right that the
collar is attached tight to the tranny, or should it be somewhat loose in
order to move?  Does this part act as a "balancer" of sort that keeps
tranny/driveline vibrations down?

just curious

gary n.