Not the usual Shift issue

[deanmcneill]

I have an '84 7.5hp Mercury outboard and the shift lever won't allow me to move out of Neutral. There is some play, but it won't go into either Forward or Reverse. I've dropped the lower unit (and it's still off) to replace the impeller and the lower unit gears work fine. It's like there's a lock that's on.

I discover the issue when I tried to put it in Forward to replace the impeller.

I looked at the original owner's manual but no info. I have the Mercury service manual but it doesn't seem to address this issue anywhere.