Merc 496 / Bravo III Knocking Noise

[ehilder]

I have a 2003 Cobalt 240 with a 496 MAG / Bravo III combo. I have been noticing some clicking coming from the stern of the boat at idle that became noticeably louder at all RPM ranges today. The noise does not change in forward, reverse, or neutral and does variate with engine power. It also does not change when turning lock to lock at idle. When under power it is hard to hear it but at WOT when listening for it at the stern, its noticeable.

It does seem to increase as the drive angle is increased from straight down at idle to full trim up.

I noticed that I can spin the props by hand but there is a slight clicking feel when turning. Drive lube is fine and has not changed.

At the bottom, a link to the noise. At the quarter half of the video you can hear it at slightly higher RPMs.

I am going to pull the drive off and see what is going on, but does this sound anything obvious?

Merc 496 / Bravo 3 clacking - YouTube

 

[Fun Times]

Re: Merc 496 / Bravo III Knocking Noise

Hi there, You may want to pull the drive off, then rig up a way to supply water to the engine at the bell housing so you can run the engine with the drive off the boat to see if the noise is inside the boat or out.

But before doing that, You may want to try running the engine while on the trailer and pump about 10 good pump of Mercruiser U joint & Gimbal bearing grease part # 92-802870A1 to see if then noise changes just for good measure.

Also remove the drive oil top vent plug to see if you have an excessive amount of metal shavings on the magnetic vent plug.

 

[cmcglothlen]

What needed being the issue with your bravo 3? I realize I’m a little late to the party here .

I’m hearing the exact same sound from my 2006 Bravo 3. Drive is now off and u-joints and gimble look just fine.

help!!!!

 

[GA_Boater]

More than late to the party. Start a thread.

Closed.