Alpha One Gen 2 strange noise

[Last Dollar]

While running the engine on the trailer with the ear muffs and water hose, if I put it in gear and advance the throttle I hear a strange screeching noise if I pull the throttle back quickly. If I pull the throttle back slowly I don't hear it so much. It's only when I rev it up some. My son's Alpha One Gen2 does not do this. The noise is obviously from the lower gear case. You can hear it inside or outside the boat. Any ideas??

 

[Bt Doctur]

With the drive all the way down and limiting the rpm to 1500 you should not hear any noise.
Have you cheked the drive oil for level and condition. When was the drive removed for service?

 

[Last Dollar]

Drive oil at proper level and the drive has a bent prop shaft that is noticeable while running in gear at idle...while on trailer

 

[Bt Doctur]

you have hit something and need a new lower unit

 

[Rick Stephens]

the drive has a bent prop shaft that is noticeable while running in gear at idle

Why would you write the first post without including this little gem?

 

[harringtondav]

I'd guess the propshaft's rear needle bearing is in a bind. If you are lucky you could get by with a new propshaft and a new needle bearing. Disassembly will tell the story. Since you'll be into full disassembly, push out and replace the forward needle bearing while you're at it. B1916 rear, B1616 front. Torrington, Timken, Koyo...Parts alone will cost $450-$550, if you have the necessary special tools.

Once you look at your repair shop's estimate, you may want to consider a complete SEI lower hsg. $895. per BT Doktur
https://www.sterndrive.cc/Mercruiser-Alpha-One-Gen-II-Lower-Only.html