The trend is that the notch or slot in the shift rod doesn't get properly lined up before the installer tries to start the cap screw. The threads get damaged, usually on the cap screw as it hits the shift rod slot edges. Best to get a new stainless cap screw before the threads get messed up in the coupler. I cut a slot in the screw to use a flat blade screwdriver, not for tightening, but for ease of starting and later removal in the future. I get so many motors here where the cap screws are damaged, I have extra ones on hand. Another note, when removing the cap screw, if it seems to be binding, try moving the coupling on the shift rod to help alignment. Many screws are damaged when they are removed forcefully.