I have some 7 speed downtube shifters that I'm having issues with. Basically, during index adjustment they shift perfectly from smaller cogs up through the larger cogs, but when going from the largest cog back down, there is a bit of extra movement in the shift lever on the plastic boss cover that screws up the index adjustment.
They're in friction mode now because of that.
They seem to be screwed on the boss pretty tight - is it just a case of worn out shifter? Or do I have the incorrect pieces that have "slop" in them? I think the plastic "mount" pieces that go on the boss first actually came with different shifters....but all were shimano and the shifters seem to fit on them ok otherwise.