I have a 4x6 probably 25/30 years old. It has always had a problem of
throwing the blade[the blade comes off while cutting]. The problem as
become progressively worse. If you remove the blade and spin the idler
wheel you can feel a roughness in the ball bearings. When taken apart
and the bearings rotated against a moving belt they seem fine. My
conclusion is that the bearing seats are not co-axial.

Now the questions:

Does this seem like a reasonable conclusion? If not what might be the
problem?

If so what can be done about it? I thought about turning down the shaft
so the bearings don't bind and seating them to the shaft with Locktite.

Any and all solutions will be appreciated.

Thanks in advance.

Chuck P.