Outboard lower unit oil color question

I have a two year old 60 HP Mercury outboard. The oil color in the lower
unit is a mystery to me. After the first three months, I drained the oil.
It had a nice, honey brown color, with some metal flaking. I refilled it
with Mercury gear oil. Nine months later, I drained it again. It has a
nice honey brown color with less metal flaking. This time I filled it with
Red Line Synthetic 75W90 gear oil. Nine months later, I drained it. This
time, it was inky black. So I filled again and 8 weeks later (being today),
I drained it and it was inky black again. I probably had the boat out maybe
10 times at most over the past eight weeks.

My understanding is that inky black oil means that it is probably old and
has not been changed for a while. That is not my situation. I do use this
outboard for duck hunting and it has seen some single digit temperatures on
the water. I have been careful to leave the motor submerged and upon
getting out of the lake, to tilt the motor to make sure the water has
drained.

I talked to both Tracker and Red Line and neither has come up with an
explanation for the color. They said if there was a problem, I would know
it. The motor seems fine though.

Here are some theories:
- The cold weather has blown a seal or cracked something where perhaps the
exhaust is getting into the lower unit. One problem with this theory is
that there is no moisture in the oil. It also seems that the lower unit
when I went to open the top two screws would have gushed out because of
extra stuff being added to the oil. That was not the case either. Is it
possible for exhaust to leak into the lower unit? What about two-cycle oil
some how getting into the lower unit?

- The Red Line oil is reacting with the aluminum housing and produced
aluminum oxide. Red Line's chemist says this would not happen. Tracker
says that they have seen different types of oil produce different
colorations including black.

- The Red Line oil reacted with residual Mercury Gear Oil when I first did
the change. That's possible, but seems like the second change with Red Line
would have eliminated that problem because the old oil should have been
completely flushed.

Anyone else have experience with this?

Jeff

I think I would contact Redline again. I know that redline gear lube in a
Harley transmission stays redish looking for a long time.

My next concern would be the metal flakes you are/were getting. If there is
something worng in your lower unit it may be getting very hot in there. I
know that is a stretch. After all it is submerged in water.

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"Jeff Durham" wrote in message
...
I have a two year old 60 HP Mercury outboard. The oil color in the lower
unit is a mystery to me. After the first three months, I drained the oil.
It had a nice, honey brown color, with some metal flaking. I refilled it
with Mercury gear oil. Nine months later, I drained it again. It has a
nice honey brown color with less metal flaking. This time I filled it
with
Red Line Synthetic 75W90 gear oil. Nine months later, I drained it. This
time, it was inky black. So I filled again and 8 weeks later (being
today),
I drained it and it was inky black again. I probably had the boat out
maybe
10 times at most over the past eight weeks.

My understanding is that inky black oil means that it is probably old and
has not been changed for a while. That is not my situation. I do use
this
outboard for duck hunting and it has seen some single digit temperatures
on
the water. I have been careful to leave the motor submerged and upon
getting out of the lake, to tilt the motor to make sure the water has
drained.

I talked to both Tracker and Red Line and neither has come up with an
explanation for the color. They said if there was a problem, I would know
it. The motor seems fine though.

Here are some theories:
- The cold weather has blown a seal or cracked something where perhaps the
exhaust is getting into the lower unit. One problem with this theory is
that there is no moisture in the oil. It also seems that the lower unit
when I went to open the top two screws would have gushed out because of
extra stuff being added to the oil. That was not the case either. Is it
possible for exhaust to leak into the lower unit? What about two-cycle
oil
some how getting into the lower unit?

- The Red Line oil is reacting with the aluminum housing and produced
aluminum oxide. Red Line's chemist says this would not happen. Tracker
says that they have seen different types of oil produce different
colorations including black.

- The Red Line oil reacted with residual Mercury Gear Oil when I first did
the change. That's possible, but seems like the second change with Red
Line
would have eliminated that problem because the old oil should have been
completely flushed.

Anyone else have experience with this?

Jeff

The metal flakes were a small amount of silver streaks. Everything I read
said this was normal during the break-in period. It was minute and it was
not in the second oil change. I have talked to Red Line. They are confused
by this also. The oil that goes in is orangish-yellow.

Is it possible for exhaust gas to leak into the lower unit? Or can, two
cycle oil some how get in there? I wondering is something may have cracked
from use in the winter, or if a gasket or seal is defective.

Jeff

"Bob La Londe" wrote in message
...
I think I would contact Redline again. I know that redline gear lube in a
Harley transmission stays redish looking for a long time.

My next concern would be the metal flakes you are/were getting. If there
is
something worng in your lower unit it may be getting very hot in there. I
know that is a stretch. After all it is submerged in water.

--
Public Fishing Forums
Fishing Link Index
www.YumaBassMan.com


"Jeff Durham" wrote in message
...
I have a two year old 60 HP Mercury outboard. The oil color in the
lower
unit is a mystery to me. After the first three months, I drained the
oil.
It had a nice, honey brown color, with some metal flaking. I refilled
it
with Mercury gear oil. Nine months later, I drained it again. It has a
nice honey brown color with less metal flaking. This time I filled it
with
Red Line Synthetic 75W90 gear oil. Nine months later, I drained it.
This
time, it was inky black. So I filled again and 8 weeks later (being
today),
I drained it and it was inky black again. I probably had the boat out
maybe
10 times at most over the past eight weeks.

My understanding is that inky black oil means that it is probably old
and
has not been changed for a while. That is not my situation. I do use
this
outboard for duck hunting and it has seen some single digit temperatures
on
the water. I have been careful to leave the motor submerged and upon
getting out of the lake, to tilt the motor to make sure the water has
drained.

I talked to both Tracker and Red Line and neither has come up with an
explanation for the color. They said if there was a problem, I would
know
it. The motor seems fine though.

Here are some theories:
- The cold weather has blown a seal or cracked something where perhaps
the
exhaust is getting into the lower unit. One problem with this theory is
that there is no moisture in the oil. It also seems that the lower unit
when I went to open the top two screws would have gushed out because of
extra stuff being added to the oil. That was not the case either. Is
it
possible for exhaust to leak into the lower unit? What about two-cycle
oil
some how getting into the lower unit?

- The Red Line oil is reacting with the aluminum housing and produced
aluminum oxide. Red Line's chemist says this would not happen. Tracker
says that they have seen different types of oil produce different
colorations including black.

- The Red Line oil reacted with residual Mercury Gear Oil when I first
did
the change. That's possible, but seems like the second change with Red
Line
would have eliminated that problem because the old oil should have been
completely flushed.

Anyone else have experience with this?

Jeff

This is just a guess as I am not a boat mechanic, so here goes. I would
have to agree with Bob L. as for the heat factor to turn the gear lub
dark or black in such a short time. Grab the prop shaft and see if you
can move it back and forth and wiggle it up and down. Maybe the bearing
carrier or the bearings are bad and the shaft is not lining up with the
forward or reverse gear and this is causing heat to darken the oil. I
don't think the oil from the power head could leak into the lower unit,
also the exhaust gasses would cause alot of blow by into the lower unit
as they are under pressure, so I don't think this is the problem either.
Next time you have the boat in the water, run it for a few miles and
when you get back to the dock go from forward to reverse a few times.
Shut the motor off and bring the motor up in the power trim and you got
to be fast as the water will cool it off and see if you can feel any
heat transmitting from the gear case. You can always go back to the
orginal gear lub and see if the problem still there. Let us know how you
do on this situation as I would like to know. Thanks and good luck.....

sket