If you haven’t already, take the time to check the lower unit over for fit of the propshaft in the supporting bearing(s). These motors are prone to worn bushings in the foot, and if you run it for very long with a loose propshaft, two things can happen that aren’t very good…
1) grease gets out and water gets in
2) the wobbling shafts wreak havoc on the gears (and possibly water pump components)
Hope it helps. Good luck with your motor. I used to own a ton (literally) of those brass lower unit motors, so I got to know many of them intimately.
Best,
PM T2
He's livin' in his own private Idaho..... I hope to go out quietly in my sleep, like my grand-dad did..... and not screaming, like the passengers in his car...