dershark3

I found the problem!!!
I took one apart and found that the final output shaft had a nick in it just about where the final output gear rides.
This is why it was so stiff to move the post up and down throughout it's vertical play.
I will try to sand down the nick with some 400 sandpaper.
It looks like a manufacturing defect.
By the way - with a 10x magnification jewlers loupe, the shaft surface looks ridged. Not smooth.
I'll let u know how the nick removal worlks out.