camshaft seal mysteries

[Dave Eaton]

replacing the cam seal on the 'rr', looking for part # 026 103 085f.  i get
specified part number 068 103 085a.  on investigation this turns out to be
the cam seal on the 'aby', 'aan', and '3b', while the 'rr', and
(interestingly) the 'adu' specify the 026 part.

what's the difference?

the cam is the same for all but the 'adu', while the head is common for
all - so there must be no difference in the physical measurements of both
cam seal part numbers.  and why do the 'rr' and 'adu' share the same seal,
while the '3b' and 'aby' (ie. S2) don't?  apart from some esoteric
difference in materials, i can only assume that the 068 part superseded the
026 part.  but then why specify the 026 for the 'adu'?

any ideas?

dave
'95 rs2
'90 ur-q