Hi all:

This sound comes and goes from use to use, but usually starts after a sustained run at full throttle. I am not so much talking about the "chirping" sound but more the squealing. I'd say it is definitely the lower unit and I have had a new impeller and drive shaft bushing put in within the last 2 years - not to say one of those parts failed or were improperly put in...
I have been told it is either a bushing, water pump impeller, and even a lower unit bearing. The sound occurs in forward, neutral and reverse once it starts.
The biggest problem is that it never makes this sound in the shop tank.
Any thoughts?