sinar F stiff shift

Hi there,

I just got an old Sinar F and the shift movement is very stiff, almost impossible to move unless the swing is first excercised for a while. After that, it is possible to shift the standards relatively easy. If the shift/swing lever is locked again, the shift cannot be done again unless the standards are first swinged...

I thought this might be due to dried up lubricant-I dissolved/cleaned it all, re-lubricated, to no avail. For some reason, once the locking lever is engaged, the stainless steel plate that holds the standard and does not go up again when the locking lever is disengaged - I guess, it is easier to swing the standard than shift it because of much larger leverage.

Talking about that, does anybody know the mechanism of locking? The lever seems to be attached to a bolt that screws into a nut that holds that steel plate. All that the locking lever seems to be doing is fastenning that bolt into the nut, I cannot see anything else moving. Figuring out how this works might help me fix the problem.

Thanks in advance,

Joseph