2007 DF90 Prop Shaft Noise

[Canto21]

Hello, i didn't find a topic to introduce myself properly. I apologize if there is one.
My name is Chris and i am having a minor noise when i turn the prop shaft by hand.

Small video i took, please turn up the volume because the noise is really minor:

https://youtu.be/qTXg2HpZxow

This noise occurs in neutral or whenever the prop shaft is turning (i put slightly forward gear in and turned the prop shaft by hand. of course there was the clicking sound because it was in gear but also i could hear the mentioned slight noise).
When the motor runs on muffs or on sea you cannot hear anything wrong at all.

I did the following things to narrow down the source of the noise:

Gear oil was like new, no metal shavings etc when i changed it out.
Prop shaft is straight and true, i checked it with a dial indicator.
I even removed the LU and removed the impeller and the gear shaft housing to troubleshoot but the noise is still there.
Also when i emptied the gear oil and turned the prop shaft the noise is just the same..like pressing sand between two fingers.

I am probably leaning towards one of the bearings of the prop shaft carrier.

Would you go into all the trouble/cost to open the LU for this really slight noise or should i monitor it and check when/if it gets louder?

I appreciate your help, thank you very much.

Chris

[tsturm]

How about seal rubbing on the shaft as it should? You are turning against 2 preloaded bearings & a double lipped (or 2) seals. Squirt some oil on the shaft at the seal see if it changes. Remember to grease the splines when you put the prop back on.

[Canto21]

How about seal rubbing on the shaft as it should? You are turning against 2 preloaded bearings & a double lipped (or 2) seals. Squirt some oil on the shaft at the seal see if it changes. Remember to grease the splines when you put the prop back on.

Good tip, thank you very much.
I added some oil on the shaft at the seal and the noise went totally away.. check here:
https://youtu.be/PZPcYqHk6QQ

That was positive because it eliminates any problem inside the gearbox which was something that i wanted to avoid as you can understand.
So the culprit must be the outer prop shaft seal for this slight noise.

When i wiped the oil though, the noise still remains, maybe just a tad lower.
I put again a bit of gear oil on and will leave it for a few hours to check.

I am beginning to think that this is really something minor and i should monitor it a bit but keep running the boat without changing the seal due to this minor noise. What do you guys think?
Chris

[Murray]

Watch for water intrusion. Run it and periodically drain LU oil to check for water, use a clean container to catch the oil and reuse the same oil if free of water. Cost nothing but your time. That’s what I did with an old Mercury and I was getting water intrusion, got me to the end of fishing season but that old motor had lots of other issues so I really didn’t care. Sold it to a kid for next to nothing he dropped $500 in parts and it’s still running.

[tsturm]

Good tip, thank you very much.
I added some oil on the shaft at the seal and the noise went totally away.. check here:
https://youtu.be/PZPcYqHk6QQ

That was positive because it eliminates any problem inside the gearbox which was something that i wanted to avoid as you can understand.
So the culprit must be the outer prop shaft seal for this slight noise.

When i wiped the oil though, the noise still remains, maybe just a tad lower.
I put again a bit of gear oil on and will leave it for a few hours to check.

I am beginning to think that this is really something minor and i should monitor it a bit but keep running the boat without changing the seal due to this minor noise. What do you guys think?
Chris

Every one sounds like this, 2 preloaded bngs. 2 spring loaded seal lips & a big aluminum echo chamber

[Canto21]

Solved!!

After leaving a bit of gear oil on the shaft at the seal overnight, today i wiped it all and... not even the slightest noise whatsoever when turning the prop shaft by hand.
This is from today:
https://youtu.be/laDfanfnLvA

Propably the outer seal was maybe a little dry from winter. So , if anybody is having a similar minor noise from the prop shaft try this first.

Thank you all for your help, tsturm you were spot on!!Cheers

[tsturm]

Solved!!

After leaving a bit of gear oil on the shaft at the seal overnight, today i wiped it all and... not even the slightest noise whatsoever when turning the prop shaft by hand.
This is from today:
https://youtu.be/laDfanfnLvA

Propably the outer seal was maybe a little dry from winter. So , if anybody is having a similar minor noise from the prop shaft try this first.

Thank you all for your help, tsturm you were spot on!!Cheers

Or when its in the water, the water lubricates it? Glad it all worked out for ya. Any time!!