115 Lower Unit Rattle

[SydneyDog]

I have a 93 115 HP, great motor. I had the lower unit welded with a small plate last fall when a hairline crack about 4 in. long developed parallel to the prop shaft. Since then I have noted a rattling sound when in gear at low RPMs. Had not noticed this before but wasn't looking (listening) for it either. Any thoughts.

[boats.net]

Sometimes a heavy or large diameter prop will cause a rattling noise at idle, you can try a aluminum prop on it to see if noise goes away.