Shifter slop

Make sure the stick is the correct width where it slides into the shifter.

I'd bet over the years I have had to weld close to 50 handles. Just did the one I own because it was never done before. For some reason, the stick is not wide enough and some one expected the bolts to hold the stick secure. Eventually, the stick wears and it feels loose. I weld them up and then grind them down so they are a tight fit into the shifter.

I know exactly what you are describing. That's the only fix I know of, other than a stick that is the correct width.