i5 coolant pump friction ring

["frank j. bauer" <frankbauer@thevine.net>]

while checking the family album for water pump part numbers, i noticed that
there should be a friction ring installed with the pump.
(051 121 017, mg 1, sg 21, ill 10-00, pos 15A)
my 86 tqw has no such thing and i don't recall any leftovers when i
replaced the previous pump.
there's no mention of it in the bentley or haynes for the type 44.
i asked an audi expert (1000+ pumps installed) and he was baffled.
rod@thepartsconnection has never heard of it.
i don't remember any discussion of this part, but i did find one reference
to it in the archives by doug quebbeman on may 19, 1998 but he got no
response to his question.
am i missing something here?

frank