I got the FD off, shaft removed, and am ready to put the new parts back on. The question I have is that when I removed the FD, the upper left (inside - near wheel) bolt had a crush washer between the swing arm and FD. The swing arm has a machined indent for it, indicating that it is intended to be there. The tech manual makes no reference to this, nor is it shown in any of the pictures. I have also looked at the OEM diagrams and do not see it mentioned or shown there either.

Each nut has its own plain washer behind it, but this one fits between the swing arm and FD. Is this needed? What is it's purpose? There was one in place when I took the FD off, but this was the second FD, installed by a guy who also put on the wrong shaft (from a pre-'06 bike

I will put it back when I re-assemble, but I just don't know why it's there and not referenced anywhere.
Thanx for your help!