Yamaha lower unit gear oil. Question..

[Fishstix]

I have a 2000 115 Yamaha outboard. I have awalys used Yamaha gear lube in the lower unit.. I did not have enough so I went to the parts store to get some they did not have any marine gear oil...14 mile round trip. I looked in the spec book and all it says is SAE90 Hypoid gear oil.. I have 3qts of Valvoline Full synthetic 75w-90.gear oil left over from another project. Should i use it? Not being cheap but I have so many odds and ends oils. 

[tech2526]

it will be fine, i had the exact same engine, used synthetic automotive gear oil in mine for ten years, no seal leak, no metal on the magnet, marine oil has the ability to incorporate water better, that is the only difference, and single weight is because outboards run in a narrower temp range than automotive rear ends do. everyone gets so worked up, keep the ”gl” rating the same or better you will be fine, and remember, an automotive oil is engineered to work under for greater stresses ”load and temp” than our outboards can exert on those gears. sorry for the long winded reply,

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[Fishstix]

Thanks for long winded reply... I went to walmart,autozone central tractor and advantage auto parts.. No one had lower unit lube.. I will run the 75/90.

Hughes Marina.... Had a camp there for about 15yrs... Might be looking to come back now that fishing is better.My camper was next to Mackerel...

[stinger]

Amazon has all the lower unit gear oils you would want and you'll have it in a couple days. Rather than spending all the time and money running around central New York you could be fishing 

[rolmops]

Just remember. 

In an emergency.
Any oil is better than no oil.

[sherman brown]

yes, you can use it because in my older motors I just used auto gear oil for years. but I wouldn't use it now except in an emergency. outboard oil has cleaners and anti-foam additive in it auto oils don't have. which means better contact with moving parts. but you can use it in a pinch but i would plan on changing it back to lower unit oil by the end of the season.