bad lower unit oil?

[jjjewett]

Hi.

I replaced my lower unit oil and it came out looking like coffee with cream. I ran the motor for around 10 hours with the new oil and then changed it again. It came out basically looking the same. I put it in a mason jar and let it sit for about a week.

For the first few days it seemed like there were white particles mixed into the oil. After 4 or 5 days the white particles have settled to the bottom and now the oil looks like this:

It hasnt changed color, just the white particles have settled.

Is my oil bad? Do I have a water leak?

My local yamaha deal said that it was fine, but he didnt see it.
I use the boat in high mountain lakes mostly over 6000'
I also usually park the boat with the motor tilted because my driveway isnt flat.

thanks,
john

 

[akmoosehauler]

Re: bad lower unit oil?

How often do you change your oil? That color means a leak in lower unit. What brand of oil? I change mine twice a year. Once in begning of the year and at the end of season. Have it checked out good. Check your seals on the fill and drain plugs to see if the are cracked. Good luck.

 

[jjjewett]

Re: bad lower unit oil?

well the motor is a 2004.

i got it about 3 months ago and have changed it twice since getting it, but the oil that was in there sat for 2 years...

 

[Major Woods]

Re: bad lower unit oil?

Water in the oil, you have a seal leak, get it fixed.

 

[Captain Paul]

Re: bad lower unit oil?

The Major is correct.

 

[jjjewett]

Re: bad lower unit oil?

thanks for the replies.

why dont i see water in the bottom after letting the oil settle for over a week? Is that white stuff water?

I have a service manual and think I will just buy a pressure tester and check/replace the seals myslef. Is this a very challenging repair?

thanks again

this is the pressure tester i was thinking of:

http://cgi.ebay.com/ebaymotors/Vacu...-Tool-Kit_W0QQitemZ370055042753QQcmdZViewItem

 

[Major Woods]

Re: bad lower unit oil?

thanks for the replies.

why dont i see water in the bottom after letting the oil settle for over a week? Is that white stuff water?

I have a service manual and think I will just buy a pressure tester and check/replace the seals myslef. Is this a very challenging repair?

thanks again

this is the pressure tester i was thinking of:

http://cgi.ebay.com/ebaymotors/Vacu...-Tool-Kit_W0QQitemZ370055042753QQcmdZViewItem

Marine lower unit gear oil has special additives designed for extreme pressure/anti-wear performance and resistance to foaming, even when subjected to 10% water contamination.
The oil will hold (will not seperate out) up to 10% water (by volume) and still protect the gears.
The white stuff is the oil holding in the water that leaked into your lower unit. The oil is doing what is suppost to do.

 

[jjjewett]

Re: bad lower unit oil?

maybe a dumb question but,

Should I do the pressure test with the oil removed from the lower unit?

-John
Reply With Quote

 

[Captain Paul]

Re: bad lower unit oil?

If the case is not cracked, you have a bad seal. I dont think a pressure test is what's needed. You need a seal.

 

[jjjewett]

Re: bad lower unit oil?

wont a pressure test diagnose a bad seal?

 

[bowhuntrrl]

Re: bad lower unit oil?

wont a pressure test diagnose a bad seal?

Absolutely !!! That's the way to test for a leak, just don't put too much pressure in, not over 10 lbs or so. Then you wait to see if it holds pressure. If it leaks or bleeds down, you can try to listen for the source of the leak.

 

[jjjewett]

Re: bad lower unit oil?

when i pressure tested today it leaked at 14psi (manual said to go to 14.2) assuming my gauge was accurate.

I heard air leaking and the sound was coming from the water intake screens.
Where would this indicate a leak from??

The prop feels like its stuck and I am having trouble getting it off. I am having trouble getting the outside spacer off.

Does it pull off, or screw off?

thanks!

 

[Yamajoe]

Re: bad lower unit oil?

we need to know model etc numbers of your motor. there will be two seals one at that prop shaft the other under your water pump, drop your oil and remove the lower unit, and someone may find a diagram for your LU. for testers you need vaccum and pressure tests; check this out http://www.mobymarine.com.au/content/popup.htm?http://stevensinstrument.com

 

[jjjewett]

Re: bad lower unit oil?

thanks.

motor is a 2004 Yamaha f25

 

[Yamajoe]

Re: bad lower unit oil?

You have a draftshaft housing oil seal and a propella shaft seal which maybe the obvious problem causing leak. replacing these are straight forward if you have the correct tools and a manual; the latter is the starting point for you.

http://www.selocmarine.com/seloc_online/repairs