blackish blue lower unit oil

[amandag]

I have twin Counter Rotating 2003 150HP Yamaha HPDI's. Last week changing the Lower unit oil, I changed the starboard lower unit oil and it looked like it did the day I put it in. Nice and amber. I changed the port lower unit oil and it was blackish/blue. It did not appear to have water in it. I have read different threads that say:<br /> 1) It is water<br /> 2) It is your counter Rotating engine and less gear oil goes in and it takes a little more of a beating<br /> 3) A bearing is going<br /> 4) This is normal.<br />I am looking for peoples thoughts on this. I put on about 80hrs this season and don't run the engines very hard. Cruise at 3,800-4,000 rpm and try to WOT for a minute at some point on the ride home to clear out the engines???<br /><br />Any help would be appreciated

 

[bigbrownbuku]

Re: blackish blue lower unit oil

its very normal for a counter rotating gbox to have darker gear oil when changing. i tell people if they are concerned to change it more often. switching to a good synthetic gear oil will also help. mercury hi performance is good oil and easy to come by.

 

[imported_Curmudgeon]

Re: blackish blue lower unit oil

I'm not understanding this. A CR is the same lower unit with a different set of gears (same number, different orientation). Why should the oil appear any different?

 

[bigbrownbuku]

Re: blackish blue lower unit oil

the gear orientation is switched in a CR box. fwd gear is now aft of the pinion and vice versa. the carrier is slightly different to accomodate the extra loads etc and for reasons unbeknownst to me the oil seems to blacken far quicker.

 

[rodbolt]

Re: blackish blue lower unit oil

part of it is the assylube that is used during assy of the CR boxes. rather than going by color go by smell.but like BenC I like the merc HP gearlube.<br /> but the moly assy lube tends to discolor the oil for a long time. in fact there is a tech bulliten on it.

 

[amandag]

Re: blackish blue lower unit oil

Thanks for all these inputs. I even called Yamaha on this and they said it is wear. I did not like that answer especially because wear is not covered under warranty. I will take the advise to use a higher quality gear lube (Maybe synthetic) and maybe change it 2 times per year. It still does not make sense that the oil would discolor that much more, or there is that much more wear on the CR side?????? rodbolt, I would be interested to see that tech bulletin on that. The only thing that does concern me is that I am an anal engineer and I would have noticed this difference over the past 2 lower unit oil changes that I have done. It seems new to me but then again it is usually cold, windy and rainy when I winterize our boat and I may have been distracted.

 

[rodbolt]

Re: blackish blue lower unit oil

go by the smell rather than color. looking through the tech bullitens is an arduous process. its there I have read it I just dont remember in which year. search through your dealers marine tech guides from 2000 to 2003 as an anal angeneer why would rotation create more or less wear> think about it.dont believe every thing your dealer says as I have found many are clueless and will say something.<br /> there are almost as many CR gearcases in wanchese as standard and the failure rate is about the same. the key is to use an engine synchronizer so one gear case is not pulling against the other. but the CR units use a molybedenum assy lube that will taint the oil color for years. kinda like prussian blue.

 

[amandag]

Re: blackish blue lower unit oil

thanks for the help rodbolt. I have heard many people talking about this assy lube that will taint the oil, I just don't remember it last year or the year before???????