Pancolar 50/1.8 - aperture not working

[VitGryfny]

Hi. Aperture of my Pancolar stopped working. It's just not clicking anymore and I am unable to set it. Aperture ring is moving loosely. The only way to set it is to use A/M switch and set it half-way or other position. I disassembled the lens by removing 3 screws and a part on a photo was not attached anyhow:

https://picasaweb.google.com/lh/photo/LmYUT-KphVwn7oHup8XMa9MTjNZETYmyPJy0liipFm0?feat=directlink

Does anyone have a clue if the spring is long enough as it seems to me like it is not pressing the teeth against which it is clicking firmly enough. Maybe I have lost some tiny part of the lens while disassembling and just did not notice it.

This is how should it look like - the part at 10 o'clock on the right hand ring.

www.kolumbus.fi/uusilehto/img/lenses/zeiss/disass/slides/step2.html (repaste manually)

Thanks in advance,
Witek