Gear Oil Shelf Life

[cogsman]

I have half a bottle of Motomaster Extreme Pressure Gear Oil 80W90. I last did my gear oil change 3 years ago (limited riding since), and want to change it as soon as the weather warms up. Does anyone know if this stuff goes bad after a while? Cap has been on the whole time. In the garage through 3 winters and 2 summers.

[Jess from VA]

It's probably fine.

I just used (fresh) 15yo 30wt in my lawnmower.

I used Amzoil synthetic gear oil multiple times over the years in my Valks (until it ran out).

It's stuff like brake fluid that once open to air goes bad quickly.

And gasoline with corn in it.  

[h13man]

I'd say the shelf life is infinite as like wheel bearing grease.

[98valk]

use your favorite adult search engine to search "Shelf Life of Motor Oil"

usually if it was at zero degrees or at 100 degrees for extended time, it should be shaken and can be used  some state even then it wouldn't be like new oil, but still safe to use and just shorten replacement mileage.

[Ricky-D]

The only reason for not using it would be that there have been good improvements in the oils that are now available.

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[cookiedough]

why not keep it inside in basement or on shelf vs. sitting in garage?   If in cold climates am sure moisture got into the bottle if below zero degrees if sitting in the garage.  still probably fine but I keep all my oil on the floor in the basement above say 55 degrees and no issues using it 10 years later even if opened, although that is extreme my oil usually does not sit for more than 2 years downstairs.

[Avanti]

I never second guess the use of a product that is way less expensive than the cost to repair what it may damage.