It is a dampener. The remanufactured axles from the autoparts stores can cause strange vibrations.

TexasHonda wrote this thread about his experience with aftermarket CV joints.

https://www.hondaaccordforum.com/for...eration-46409/

Thanks! I was thinking that's what it might be. I wonder if it can be swapped over to the new axle. Probably be a PITA at this point now that the new axle is installed - unless it can be cut off and still be able to be reused?

IMO, at this point it is too late. Best to get a new shaft with the ring/damp on it and go from there.