jaminb
Active member
I would like to change my Yanmar gearbox oil. Should I run the engine in gear first?
Thanks
Thanks
Changing gear box oil
- Thread starter jaminb
- Start date
westernman
Well-known member
I doubt it will make any noticeable difference. It will take ages for it to get warm enough to make any difference.
Refueler
Well-known member
The advantage of running in gear for a short period - is to stir up the oil and any sediments etc that may be in bottom of box.
I do not do this every year - in fact I don't do it !! But this year I am considering giving my engines / gearboxes a birthday ..... suck out oil with the Pela - throw in light machine oil as a flush - give a short run just to flush round - suck out and refill with new correct oil.
I do not do this every year - in fact I don't do it !! But this year I am considering giving my engines / gearboxes a birthday ..... suck out oil with the Pela - throw in light machine oil as a flush - give a short run just to flush round - suck out and refill with new correct oil.
PaulRainbow
Well-known member
That might be OK with your transmissions, but it would cause some problems with others.
Refueler
Well-known member
Boater Sam
Well-known member
Leave any sludge where it is, stuck to the bottom of the casing. Stirring it up is the last thing to do.
Running a box with the incorrect thin oil or solvents is a bad idea and will damage some boxes severely.
It is easier to pump oil out with a vacuum pump if it is warm but if dropping it from a drain plug it is not necessary.
It is better to drop than suck, because any loose sediment will come out with the oil and you can clean the drain plug which is often a magnet to pick up swarf.
Running a box with the incorrect thin oil or solvents is a bad idea and will damage some boxes severely.
It is easier to pump oil out with a vacuum pump if it is warm but if dropping it from a drain plug it is not necessary.
It is better to drop than suck, because any loose sediment will come out with the oil and you can clean the drain plug which is often a magnet to pick up swarf.
westernman
Well-known member
I don't think Yanmars have a plug on the bottom.
Boater Sam
Well-known member
I thought it was a gearbox not an engine?
Daydream believer
Well-known member
Oiy
Don't start winding each other up. You know what happens.
By the way- what is wrong with Castrol solvent flushing oil? or is that not to be used in gear boxes
jaminb
Active member
Conclusive! Yanmar gearbox don't think there is a sump plug so was going to use my Pela pump.
Dellquay13
Well-known member
Maybe it flushes well but doesn’t lube enough to protect the gears if you try giving the boat a bit of a run to flush the old oil? Maybe just a quick tickover burst of fwd then reverse to stir the flush round rather than a bit of a run?By the way- what is wrong with Castrol solvent flushing oil? or is that not to be used in gear boxes
Refueler knows about oils so I may be wrong…
Daydream believer
Well-known member
Having googled it--Seems Flushing oil is made for gearboxes as well as engines & is recommended for a number of reasons
westernman
Well-known member
OK I will spell it out.
I don't think the gearboxes which are normally attached to Yanmars have a drain plug at the bottom.
PaulRainbow
Well-known member
PaulRainbow
Well-known member
Marine gearboxes use a variety of lubricants. Using any old flushing oil, or flushing with an incorrect oil will cause damage, especially if you engine is run in gear whilst flushing.
If your gearbox needs flushing you should change the lubricant more often.
If your gearbox needs flushing you should change the lubricant more often.
PaulRainbow
Well-known member
Just pointing out the potential for causing expensive damage by using the wrong oils in a transmission.
Refueler
Well-known member
Are you old enough to remember the days of Flushing Oils used in Cars ... Motorcycles .... static engines ... etc. ??
The Flushing oil was only in for a very short run - just enough to pass it round the system to flush ... drained and then correct oil put in.
Are you aware of a few car models changed from Gear Oil to Hydraulic Oil in SAME gearboxes ... due to lack of oil feeds to one or more layshaft ?
I certainly would not suggest running the engine or G/box for any length of time .. its a FLUSH .. you know stick it in .. start - run - stop - drain.
Daydream believer
Well-known member
I recently found an article that said that the Caterpillar D2 manual says to drain transmission and final drives, fill with kerosene, drive around for 10 minutes without any load, drain and fill with the correct oil.
I would not suggest that but I do recall using flushing oil in our dumpers, 60 years ago. But not exactly precision gearboxs & engines
PaulRainbow
Well-known member
What people did with cars and motorcycles 50 years ago has no relevance to todays modern engines, transmissions or lubricants. It most assuredly has no relevance to some of todays modern marine transmissions.
Putting light machine oil in some marine transmissions will cause problems, no matter how short a time it's in there.
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PaulRainbow
Well-known member
The manual for the engine on my RIB says to fill the fuel tank with pre-mixed 2-stroke, does that mean i should do the same with the main diesel engines ?
