I have an nv5600 that is grinding in one of the gears, do the replacement pieces have better lining material than the originals? I am not sure of the exact term for the part with the lining, I think maybe it's the blocker ring?

 

All the blocker rings have the same part#, what I want to know is have they improved the lining material or is the replacement gonna wear out in a couple of years or is there an after market source for high quality rings?