Mercruiser 5.7L competition ski squealing noise when driving under load randomly

[Jake13492]

When driving or starting to pull someone out of the water it will make this sound only sometimes not all the time wondering if anyone would have any idea what it might be where I could start looking to find the issue it has a FNR gearbox

 

[Scott Danforth]

Check the alternator belt and power steering level

 

[bbook83]

I have run a 5.7 liter Competition Ski with a Borg Warner velvet drive (fnr) behind a Walter V-Drive for the last 26 years and have fought belt squeal a lot, going through several serpentine belts, but your recording does not sound like belt squeal, although recordings are tough to analyze. Check the gearbox fluid level (Dexron IIl ATF?) dip stick while hot and try to get close to the engine and gearbox to isolate the source of the sound. How many hours on the whole set up? Any reason to suspect shaft alignment?

 

[bbook83]

I have run a 5.7 liter Competition Ski with a Borg Warner velvet drive (fnr) behind a Walter V-Drive for the last 26 years and have fought belt squeal a lot, going through several serpentine belts, but your recording does not sound like belt squeal, although recordings are tough to analyze. Check the gearbox fluid level (Dexron IIl ATF?) dip stick while hot and try to get close to the engine and gearbox to isolate the source of the sound. How many hours on the whole set up? Any reason to suspect shaft alignment?

I have also heard rattling noises when idling too slow in gear that people smarter than me have said are coming from the damper plate, which is attached to the engine flywheel.

 

[Scott06]

I have also heard rattling noises when idling too slow in gear that people smarter than me have said are coming from the damper plate, which is attached to the engine flywheel.

That would be my thought based of the very limited video. Would try and listen with a mechanics stethoscope on flywheel cover to see if that can be confirmed. Would also make sense it is dampner plate if noise occurs under heavy load.

 

[kenny nunez]

The rattling noise is the flex plate which is no real problem.
The squeal could be the outer ring of the harmonic balancer. Or if there a buildup of black belt dust on the engine? If the outer ring is not slipping try dis connecting the alternator wire to see if the noise goes away. If squeal goes away then maybe a slightly larger pulley on the alternator is worth a try.