If waxing & oiling didn’t help, I would be reluctant to mar the fine finish on the shaft, using any sandpaper, and possibly expose even its hardened stainless steel surface to premature rusting, or just eventually picking up “unsightly” dirt in the scratches left behind.

 

    Are all of your counterweights equally tight on the shaft, or is it maybe just one?

Or perhaps the cwt knob lock pin is not fully retracting from the shaft?

As a test, remove the locking knob and its brass pin from one of the cwts, and see if the tightness and noise diminishes – if so, maybe the locking pin hole needs a drop of oil to full retract from shaft.

 

    Hard to say if the shaft or the counterweight bushings are (unusually) very slightly out of diameter spec – but stuff happens.

    Instead of the cwt bar, I  would prefer to sand the inside of the cwt’s  brass bushing. You can choose  a suitably  fine grade of grit,  wrap a turn or even just a half turn to the” near”  (but not right at),  the lower end of the shaft.  Scotch tape it to the shaft using double sided tape  to keep the sandpaper in place for this task. Then work each counterweight onto the end, and spin it on the sandpaper, using the shaft as a “snug fit mandrel”. That saves a lot of work doing this with a finger, and the enlarged hole would be more precise.

 

    You should be able to sand down the brass as you twist and work the cwt gradually UP the shaft over the sandpaper strip. After a few turns, work it back down to the clear spot,  to test fit it to the exposed lower end of the shaft below the sandpaper. Repeat if necessary.

 

    The downside to this solution might be that the brass bushing will not spin on the sandpaper, but will instead grab onto the sandpaper and rotate inside the stainless steel cwt hole. The brass bushings are just “press-fitted” and not glued inside the hole – which BTW,  would have been a good idea.

 

    Just a thought,

Joe