Mercury Inline 6 115HP - Strange Noise, Please Help

[DACKS]

Hello bright minds and good people of Scream and Fly.&nbsp; This is my first post so please take it easy on me if I ask a stupid question.<br>I got a 1984 Mercury Tower of Power Inline 115hp.&nbsp; &nbsp;<br>It just started making a strange noise that I nor a local experienced Mercury mechanic could pin point the cause of.&nbsp; In all gears F-N-R and responsive to increased throttle (increasing in pitch) it makes a "squeaking and almost whining/choking noise".&nbsp;&nbsp;<br>The noise just appeared out on the lake one day and hasn't gone away.&nbsp; The engine has lost no power or performance and both the mechanic and I agree its not the dreadful "knocking" noise. I asked about the top or low end bearings and he said, "no doesn't sound like any bearing issue i've ever encountered".&nbsp; <br>It appears to come from the top end, but we both agree anything along the drive shaft can make it tricky to find exactly.&nbsp; I pulled the flywheel changed the shaft seal and top end cap o-ring, no change in sound.&nbsp;<br>Any advice or thoughts would be appreciated.&nbsp;

[Dave S]

Rear bearing on the R gear in the lower uint......had one drive me Crazzy..... yepp.

[DACKS]

Well it would have been a long way down the check list before I got to that, I appreciate the advice. To clarify the bearing in question is circled in red?

[bullet123]

if you cant or don't want to fix it, I have a l lower off of a 1981 that I will never need. You can have for $50. You just have to come pick it up

[rhardwick]

The inlines went through a lot of pistons, rarely a crank bearing failure.