Gear Oil Change!

[Mac_Attack]

Hey everyone I have been draining the leg oil out of my motor all night to ensure none left in it and i woke up this morning to see that it had a fine milky layer on top with some shades of green :o I have always used Quicksilver Premium gear lube and never had this problem. It recently put it in for a service and they changed the gear oil with some crap stuff by the looks of things my question is what oil to use and what to not? I Use Quicksilver
Cheers Nick 8-)

[peterbo3]

That fine milky layer could be emulsified oil & water which is never good. I suggest you find a new mechanic & have the gearbox pressure & vacuum tested. Take the old oil with you. The problem may be as simple as an incorrectly tightened filler or drain plug from the last "dodgy" oil change.
Which reminds me, was there a gasket on both the filler & drain plug when you removed them? They are a 50 cent item & should be replaced every time you pull a plug but some cheap mechanics reuse them or do not replace them at all & the plug may not seal correctly allowing water entry.

[FNQCairns]

Hi Mate close your eyes and stab at a brand, it's all simply automotive hypoid diff oils anyway, except in our imagination, some say that it has extra emusifiers in there, those that know say if it has something extra like that then they would be taking away some of the lubricant properties, their is only so much space to place additives in the first place.

Anyway if you choose to find a good synthetic diff oil in the 90wt range you will not do better than that no matter which Marine sticker oil you buy.

cheers fnq

[PWCDad]

The one guaranteed way to to get the bungs done up right ...

Use new gaskets as stated above.

Grab a 3/8th drive blade screwdriver that fits the slot properly ... attached it to an "inch pound torque wrench" ... look up torque setting in manual (service man as owners may not have it) .... tighten to "click" .... done !

Recheck torque after first run ...

Oh to find a marine tech that does it as the factory specifies ..... Sigh !

PWCDad

[Spaniard_King]

Anyway if you choose to find a good synthetic diff oil in the 90wt range you will not do better than that no matter which Marine sticker oil you buy.

cheers fnq


Be carefull, some engine brands do not recommend synthetic gear oils for their gearboxes.

[BaitThrower]

All the service manuals I have read suggest that there is water contamination if the gear oil appears milky :(

[PWCDad]

The synth in some cases may cause the seals to leak. Older seal composition may not be suitable for synth base oils and soften losing lip tension.

As a matter of service ... when the seals are replaced with modern composition seal formulas it should be fine with synth... but ...

No one knows their motors more than the manufacturers ...I'd always follow their recommendation. IMHO.

PWCDad

[FNQCairns]

Be carefull, some engine brands do not recommend synthetic gear oils for their gearboxes.

Gary why is that is there some soft metal (yellow) in Honda or other box's?

Often manufacturers preclude doing the best for engines, sort of like dumb it all down to keep control of the variables and help funnel consumable product dollars their way but it also has the ability to lessen total service life.

Cheers fnq

[Spaniard_King]

Fnq,

Honda is one who does not recommend sythetic oils for the engines or gearboxes. I personally have had to repair some boxes that have had faiulures due to synthetic oils.. I find that the box has burnt the oil and it eventually breaks down the case hardening on the gears when this happens. In some cases I have been lucky enough to catch them before they were damaged, changed them back to 90wt hypoid gear oil and they have been fine. These boxes work in the harshest enviroment.. the water taxi.

[4x4frog]

My suggestion is from years of car service/restoration experience. If the manufacturer says a particular type of oil, stick to it. Don't use synthetic where it specifies mineral because most times the bow/engine was manufactured with the oil type in mind. Synthetics are not suitable for older style castings/metal compositions and like mentioned cause breakdown of the metal structure which is obvious in what it will lead to.:(

[PADDLES]

garry, i have been led to believe that using an oil specifically designed for outboard gearbox applications and not for automotive applications was the go because of the fact that the gearbox rapidly cools because it is immersed in cold water. is this correct in your opinion?

[FNQCairns]

Thanks Gary interesting info to chase up why, considering lot's of claimed synthetics are mineral oils anyway and a legal loophole is the major difference.

Do you have any idea what component of the oil was burning -could they have also added some snake oil additive but kept it quiet, as people do when things go wrong, esp under warrenty?

Yeah 4x4 one of the risks is soft metal like I outlined above although we are not delaing with syncromesh gearbox's on outboards so even GL5 diff oil is OK.

cheers fnq

[Spaniard_King]

Paddles.

I don't think there is any additive in "outboard spec" gear oil that will aid the gearbox if it has water ingression.. if the seals cant keep the moisture out the oil isnt going to make a difference.

FNQ, you are right GL5 is what I use and if you read on the products supplied by Honda they are made by caltex... EP80W90 is what they use.

[PADDLES]

yeah i know that water is the enemy, but was more interested in comparing marine gear oil to automotive gear oil.

[FNQCairns]

yeah i know that water is the enemy, but was more interested in comparing marine gear oil to automotive gear oil.

Paddles I know it makes sense to believe other wise but there is no advantage adding anything above what a good automotive diff oil already has in it's additive pack, adding anything else or changing the additive pack/parameters would/could make for a bad oil that shouldn't even be used in vehicle gearbox.

So the difference is 2 things the packaging and the colour tint used to 'make' the oil for use in a marine application.

cheers fnq

[PADDLES]

thanks for the info guys, we've done a bit of work here over the years for an australian based oil manufacturing business and so have seen how the oil comes out of the one bulk drum into a number of different packages with different labels on them. was just interested if there was a fundamental difference but it appears there isn't.

[FNQCairns]

Hey Paddles not expecting anything, although if possible could you fill me in on a couple details via PM will keep all but the basics mum. Again no problem if it is a problem.

cheers fnq

[Spaniard_King]

Paddles,

Caltex EP80W90 is an automotive gear oil which is in the recommended range for use in Honda outboards. I fail to see how the use of synthetic oils in outboard gearboxes will give extended life after all they are a basic differential construction

[Mac_Attack]

Thanks so much for your help guys took the washers off and had a look the mechanic i took it to changed the gear oil and used the washers again (part of the 100 hours service thing) I went down got some new ones 50 cents each. Now i know why i was getting water in there!
Cheers Nick 8-)

[4x4frog]

Thanks so much for your help guys took the washers off and had a look the mechanic i took it to changed the gear oil and used the washers again (part of the 100 hours service thing) I went down got some new ones 50 cents each. Now i know why i was getting water in there!
Cheers Nick 8-)
I fail to see why for the sake of $1 that mechanic didn't change the washers. The big question is, did he include a charge for miscellaneous parts on your invoice?

[FNQCairns]

Yes it is expected that every time those screws are loosened a new washer is needed.

cheers fnq

[Mac_Attack]

I fail to see why for the sake of $1 that mechanic didn't change the washers. The big question is, did he include a charge for miscellaneous parts on your invoice?
He did not put down anything like that but he did write (your gonna like this) $30 for filling down the leg were i have put a few little bumps on it! WTF!!!!
Then he put shit oil in it it was like water?
Cheers Nick 8-)