Gear oil alternative in the middle of nowhere?

[a64pilot]

Different gearboxes need completly different kind and types of oil, way different viscosities too.
Huge farm tractor transmissions and now many automobiles manual transmissions use hydraulic fluid or automatic transmission fluid which is thin as water.
Helicopter transmissions that hold thousands of HP use 23699, an oil that is thin as cooking oil or thinner, but they are designed for that.
I have no idea why or what is different, but different gears apparently require way different viscosity of oil.
I am not abdicating using motor oil in an outboard gearcase, but if its was all I had, I'd use it until I could get the correct oil, just like if I was down a couple of quarts on my Yanmar, I'd use straight 30W car oil if it was all I could find, I wouldn't let it run low.

[Cheechako]

Where are you in the Bahamas? Ask on the VHF if anyone has some to spare. Check out the dive shops with boats, they likely have some. Hard to imagine not finding some in the Bahamas, you apparently have internet service so you must be near some populated area?
Are you sure you are low? How low? Those little OB's hold very little actually.

[Cadence]

Originally Posted by Cheechako

Where are you in the Bahamas? Ask on the VHF if anyone has some to spare. Check out the dive shops with boats, they likely have some. Hard to imagine not finding some in the Bahamas, you apparently have internet service so you must be near some populated area?
Are you sure you are low? How low? Those little OB's hold very little actually.

Best post!

[deblen]

lower unit oil - The Hull Truth - Boating and Fishing Forum

/ Len

[buzzstar]

The real bottom line is that you need the proper oil. If you are near anywhere where gears are used to transfer power produced by an internal combustion engine to wheels, a prop, or almost anything else, you should be able beg, borrow, or buy something close to what is called for if not the same stuff. Mix with what you have if not the same, and drain and replace properly at the first opportunity. Try to use your outboard both lightly (no more power than absolutely needed) and run it for as short of time as possible. Just as an example, I actually used olive oil once because it was all that was available. It worked for the short time that it was called upon.

[mholubec]

Ok
Two issues here
If the royal purple is motor oil I am assuming since its 10/30 it is then its I hi detergent oil not sure if I would do that great oil but not sure about HD oil in the application
Now that being said if the oe calls for a non detergent oil then as stated in previous post correct is best the closed match to the correct viscosity is better
Then any oil is better than no oil
But again as stated earlier I would go find the local i can see not finding some kind of synthetic but there should be some kinda standard simple oil within 10miles in the islands
Cheers

[etterridge]

Have you asked fellow boaters, say for example at sundowners? Most cruisers will have some aboard to spare.

Presumably its a small outboard, so you won't need too much.

On islands that lack a Napa store you will find boat needs such as this commonly at a general or grocery store.

Always stock-up beforehand.

Especially when you're going where people are'nt.

[rwidman]

Originally Posted by epiic

I am low on gear oil in my Mercury 9.9hp outboard in the middle of the Bahamas with no store anywhere nearby that sells gear lube.................

I'm sitting here wondering how you know you are low on outboard gear oil and if you are, where is it going? An outboard doesn't consume gear oil. And if you have a bad seal, usually water comes in, the oil doesn't go out.

Now if you really are low on outboard gear oil and can't find any, you would be better off emailing the manufacturer with your question than asking boaters who may not also be experts on your motor.

[Diesel Bill]

My Mercury owners manual states to use their Quick Silver lower unit gear oil as it has additives for water protection against corrosion. It also states if unavailable to use automotive gear oil and change out when available. The Quick Silver oil is gear oil with the corrosion additive, otherwise it's just gear oil.

[Sailorbob8599]

To start with, I don't understand why anyone would go cruising without being prepared. That means having spare containers of both motor oil and gear oil aboard; (unless you've used up your on-board stock while cruising). If so, you need to fix the cause of the power unit from using or losing oil, whether it be the lower unit or the engine itself. In either case, you failed to make sure your O/B was mechanically fit to go on a cruise. O/B's do not 'use' gear oil, and if the engine uses motor oil, you should have overhauled it prior to going on that trip.

It's many years since I've owned an O/B, but if I remember correctly, I believe you need to fill the gear section by inserting the tapered nozzle of a plastic tube of oil in the lower hole and squeeze the tube until oil exits the top hole. If that is still the approved method, you need to get the proper tube of oil surely????? Although . . . I suppose any method of getting the oil into the lower end is better than no oil at all.

The problem with O/B's is, anyone can buy one and operate it, but it takes experience and knowledge to know what to do in an emergency. Finally, it's my practice to carry an abundant supply of lubricants aboard whether I need them or not. Oil doesn't go "bad" in a sealed container and you never know when some other boater may be in need . . . such as the OP.

[MarkSF]

From Wikipedia :

"API viscosity ratings for gear oils are not directly comparable with those for motor oil, and they are thinnerthan the figures suggest. For example, many modern gearboxes use a 75W90 gear oil, which is actually of equivalent viscosity to a 10W40 motor oil."

Many British Leyland cars had the gearbox lubricated by the engine oil, but I believe that they couldn't use hypoid gears, as that requires an Extreme Pressure lubricant.