C4 stator support/forward clutch sealing rings ????
Those sealing rings are the reason everyone says to keep endplay to a minimum. minimum endplay means the rings do not move back and forth on the grooves.
Teflon is better because they can form to the drum and the sides of the groove. When the high line pressure is applied to the drums the teflon will also slide better on the groove.
I think the teflon is only available for the narrow grooves, I would have to loook but I beleive my pump has wide grooves and I have to use metal rings. Or it could be the other way around. LOL