I need a little help, High Pitch Whine in forward idle and when coming off plane

[ryguy1188]

I have a 2011 Axis A20, and I am trying to figure out what is causing these noises. I think they might be related.

1st sound) I noticed last weekend that I am getting a high pitched squeal-like whine when I am idling out through the no-wake zone. As soon as I put it into neutral it goes away. If I take off, the sound goes away or is either drowned out by engine sound.

2nd sound) A few weeks prior to that I have also noticed a similar sound to the 1st, but much louder and for a shorter amount of time. This happens whenever I am slowing down and coming off plane to pick up a fallen rider. It usually happens with full ballast and slowing from around 19 to 5 mph. As soon as the boat is slower than 5mph, the squeal goes away and back to the 1st sound at forward idle. To describe the sound, it sounds almost like removing a metal nut on a bolt that has rust on the bolt threads.

Things inspected) I've check the transmission fluid level after warming up and checking right after engine is turned off. The engine belt is tight and not slipping. The prop shaft spins relatively easy.

I have no idea what else to inspect. Any help will be appreciated! 

[ct77]

I'd look at the prop shaft as the source. Can you remove any cushions and have someone with their ear down there listening while you drive?  What style packing nut do you have? OJ, PSS, old style Brass nut?  If it's the PSS, I've read that it can make noise when seal/bearing is bad or out of adjustment.  If it's the old style brass nut stuffing box it can make noise too if there's not enough drip. 

[tvano]

prop could be singing. search this site for more info.

i suspect you have a serpentine belt but if it's old style make sure it's tight.

in fact, if it is serpentine, if the belt tension assy. isn't functioning you could get some noise there, too.

[ryguy1188]

2 hours ago, ct77 said:

I'd look at the prop shaft as the source. Can you remove any cushions and have someone with their ear down there listening while you drive?  What style packing nut do you have? OJ, PSS, old style Brass nut?  If it's the PSS, I've read that it can make noise when seal/bearing is bad or out of adjustment.  If it's the old style brass nut stuffing box it can make noise too if there's not enough drip. 

yeah, I can remove the transmission cover which should help determine where the sound is coming from. 

I'm not sure which style I have, but this is a picture of it. If I suspect the sound is coming from the seal/bearing, is there another way to verify it, like play in the shaft etc.?   

1 hour ago, tvano said:

prop could be singing. search this site for more info.

i suspect you have a serpentine belt but if it's old style make sure it's tight.

in fact, if it is serpentine, if the belt tension assy. isn't functioning you could get some noise there, too.

 

I have the old style V shape belt and it is very tight.

 

 

[formulaben]

1 minute ago, ryguy1188 said:

If I suspect the sound is coming from the seal/bearing, is there another way to verify it, like play in the shaft etc.?

Next time out I'd just try to get a pair of ears down there to locate it...if it were me, I'd disconnect that hose and spray some WD-40 in there and see if it temporarily quells it.  If so, you found your problem.  Also, maybe disconnect that line at idle and make sure you have good water pressure to the seal.