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I have this residue in old gear oil. I left it in the jar for a few weeks to check because when I changed the oil it didn't look as uniform as I expected.
It doesn't look like water but I'm not sure. I know there are some additives in marine gear oil but I don't expect they are supposed to be separated from the main oil.
Any thoughts?
Thank you!
Contaminated. It should have nothing but the honey coloured oil in the jar.
Thanks.
I guessed the same too, but what is that? It doesn’t look like water, is it?
How would I determine what is that and where to look for a problem?
Definitely contaminated. Check your seals. One of them is likely cracked and leaking. I have a Mercury 25 four stroke with a completely grenaded lower unit upper drive shaft bearing that's only 6 months out of warranty. The lower unit gear oil has been changed annually with the levels checked before launching last week for the first time since duck hunt last fall. It'll be interesting to see what happened with the bearing running dry.Quote:
Originally Posted by MarkD
Water in the gear oil. Bad seal around prop shaft or if you have a bad pair of washers on the drain and fill bolts. Could be a loose bolt as well. Take it to a mechanic. They will pressure test the lower unit.
Thanks Fenelon,but,that's already been done. Gear oil level is correct,winterizing was done properly (by me) with no evidence of leaks over the winter. Oil levels were re-checked before spring start run-up. Everything seemed in order before launch,but,10 minutes out,the main bearing seized locking everything up instantly. Sometimes,stuff just happens for no particular reason. I'm told that this happens very rarely with Merc's,but,it's quite common with Yamaha and Tohatsu. With the warranty expired,this one's gonna hurt.Quote:
Originally Posted by Fenelon
Marine oil has emulisifiers in it, when mixed with water this turns whitish and floats on water so it can be cleaned up from the environment in case of a leak into the lake.
When in doubt ... change it out. Ideally there should be nothing but gear oil in there and not some milky mixture that's why it is most important to change the oil at the end of the year in case water did find a way in so that the water doesn't freeze and burst seals/casing etc.. Gear oil has two main functions , one as a lubricate and the other to transfer heat. Water will do the same thing but not as effectively. You may also want to put a magnet in the old oil to see if any metal is in it ? As for bad bearings ? It happens ! Not like manufacturers are using Swedish or German made when there is cheaper ones to buy ?
Thanks a lot!
I took some time trying to figure it out..
I watched some youtube videos and was really surprised to see how one guy changed gear oil and found clear water, not emulsion, flushing from the hole.
The thing is that I didn’t change it at the end of the season (I know it’s wrong) and changed it recently prior to putting the boat into the water. Even if there is water, still no full separation occurred, as you can see. The sediment is still a sort of emulsion, not clear water.
My main concern is the slightly gray color, as I read that this is a bad thing, worse than just whitish milky color.
I then put the same oil in the jar, added some water and agitated it at high RPM for ½ hour.. Now, after four days it is still emulsion, no separation occurs.
The motor is relatively new, I bought it in 2018 (oh, well, not so new, the time passes really fast…), it is a Tohatsu 20 HP, made in Japan.
My plan now is to make several outings and drain the oil. If there is something wrong again I’ll probably need to do a pressure test.
I’m planning to deal with it myself, bringing the boat to the marine for service is not an option for me.
IMO -Quote:
Originally Posted by MarkD
- The slightly grey vs milky white doesn't make a big difference.
- You won't get the oil / contaminant to separate. It's not supposed to.
My 2001 mercury 25hp - bought new - always had milky looking (now grey) gear lube when I changed it.
It is important to change the gear lube when you put the boat away in the fall, not when you take it out in the spring.
I really appreciate your answer, this helps a lot!Quote:
My 2001 mercury 25hp - bought new - always had milky looking (now grey) gear lube when I changed it.
Me too, whenever I change the gear oil in my motors (I also have Honda 2 HP) I see some milky stuff in small quantities but I never investigated it before (leaving it in the jar for some time).
I’m still now planning to check/change the oil after several outings and yes, I’ll never leave the old oil in the unit for winter anymore.
^^^Bingo! Your better off too drain and leave the bottom end empty rather then leave the old in over the winter. But we always put fresh oil in the fall before storing.
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Right. I was thinking about it too.
I never felt well to leave oil for 6 months and then use it for another 6 months…
For some reason for the car engine it is recommended to change oil either after a certain mileage or after a period of time, whatever comes first, right?
Anyway, it was my pure stupidity to leave the old oil for winter. I'm happy that it seems OK so far, but I learned my lesson.
Thanks.
What about this video?
https://www.youtube.com/watch?v=xMv-JyLxkks
Watch it from 8:00 Pure water flashing out from the gearbox and then some oil/water mixture, but not emulsion.
Is it real or staged?
Also note that used oil is deep black in color. I first thought that he uses blue colored marine gear oil (available in Canadian Tire) but if you watch how he changed the oil on his first motor (he has two Yamaha 150 HP) you could see that he is pumping in normal honey colored oil.
What is that?
That's real,Mark. I've had it happen just like that where the seals were completely broken,the oil leaked out and the lower unit filled with water. There was no mistaking the clanky sound of metal on metal. Changing the seals are easy. Check for excessive metal debris on the magnet plugs,refill with gear lube and you're good to go. The repairs I didn't have the equipment to do on my motor mentioned in post #4 totalled $515.50 PLUS Trudeau taxes at a repair shop. Not as bad as I originally thought,but,still pricey. We have no idea what caused the main shaft bearing to fail. Gear lube level was spot on,seals were good,some things make one wonder.Quote:
Originally Posted by MarkD
Thanks!
For some strange reason, neither of my two motors, Tohatsu 20 HP and Honda 2 HP, have magnetic plugs but just regular bolts.
I checked the old oil in the jar and found two small visible metal (magnetic) pieces, probably not more than 0.5 mm diameter. Probably not a very good sign but hopefully not really bad.
The thing is that I have a quite small, 16’ aluminum utility boat, and I cannot carry additional means of propelling in it, but I usually go several miles of shore (in quiet weather only) in GB and LO for trolling. … So if the motor fails I don’t really know what to do…
I have a 24V Motor Guide 45lb thrust mounted at the bow of my old 16' Misty River that weighs a half ton. If it wasn't for that and the batteries charged up,I'd still be paddling. If you're going out on big water,you should really think about hooking one up. They can save a lot of aggravation in a pinch. Besides,they're worth gold navigating shallow marshes.Quote:
Originally Posted by MarkD
Yes, I was thinking about something like that for a while… Still thinking.
Thanks for the suggestion!
Chances are the lower end shouldn't pack it in as you have changed the gear oil before going out. Even if a bit of water gets in you should still be okay because many of us find milky oil come the end of the year but yet the motor ran fine until it was time to be put to bed for the winter.
I run approx. the same type of rig you have but for duck hunting and invested in a handheld waterproof VHF radio as a "just in case" . Cellphones are not always dependable but my Uniden Voyager always did plus it had the Marine Weather channel on it too. Ideally/legally you should get the Operators Licence to use it but it's not against the law to own and "listen in" to one. I would advise reading up on how to use it properly as there is special terminology ( Pan, Pan vs. Mayday, Mayday) and phonetics ( A=Alpha, B=Bravo) involved.
Thank you very much! That's a good idea too.
Exactly....that's why I'm sure it was just a bum bearing. The dealer wasn't about to admit that.Quote:
Originally Posted by longpointer