LU oil greyish color

[notamechanic]

I have a 2015 F 300 UCA. I did my 25 hour service at about 30 hours then at 100 hours. When I went to change the LU oil for the winter the oil came out with a greyish tint to it. There was no water in the oil and no pieces of any metal on the magnetic screws.
I know that you are supposed to use Yamaha HD LU oil. I am thinking the mechanic used the wrong gear oil on the last service.
Is there a possible LU problem arising? Or is this part of the break in? The engine ran perfectly all season.

[zenoahphobic]

They would have warrantee services by authorised Yamaha dealers.
I'd go back and compare your oil with the color of the oil they use.
If you wiped the plug with a clean paper towel some smudge would be evident. Also no visible water doesn't necessarily mean no water has mixed with the oil.
Grey suggests excessive wear.
What prompted you to do the oil and did you see it prior to this occasion?
Question your servicer.

[notamechanic]

I did not see this color on the previous change. I am thinking they didn't use HD oil. I am going to be doing most of the work myself now because after 15 years using the same shop their prices are going thru the roof.
The grey color suggested to me like there might be a future bearing problem. I have approx. 280 hours

[robert graham]

Change oil with specified: "Marine Lower Unit Oil".... The Walmart brand is fine but other brands are O.K.also.....put new drain/fill screw washers....run the motor and re-check oil...my guess is you're in good shape.

[99yam40]

Take a sample back to those that changed it last time to see what they have to say.
Or better yet send off a sample to have it analyzed to find out what it was and what is contaminating it

[TownsendsFJR1300]

It shouldn't be grayish, its not normal..

Darker with wear and tear, but gray is indicative of water intrusion.

I'm not sure if your particular LU is pressure tested or vacuum tested for leakage but I'd be getting it tested for any leakage while the LU is empty of oil..

Please post back what you find and good luck.

[notamechanic]

I will not be able to do anything for a couple months as it is winter here now and the boat is shrink wrapped. I did save a small sample for a month and noticed no water, no smell. I wound up just tossing it out.
My plan is to crank her up in the spring, let her run for a few then change it again. I will splash boat run it for a month and check again.
This is a brand new engine with a 5 year warranty, if there is a problem I rather have a new one under warranty than a possible fix.

[notamechanic]

I just looked at the bill, it seems they listed Etec lower unit oil as what they used