timing chain cover nuts and seals

[chancecasey]

1990 964 3.6L

When going back together with the 18 nuts, flanges, and rubber seals (o rings), to put the covers on the timing chain housings, I noticed a funny thing.

On only 6 of the nut/flange/o-ring assemblies, there was a plain flat washer stuck between the old seal and the flange.

So, that's - stud, cover, o-ring, WASHER, flange, nut.

I don't know if there are 6 "special" ones from the factory or perhaps someone did this to squish the o-ring down more to stop a leak.

Any ideas?

-Chance