Does oil, specifically gear oil have a shelf life? I have 3l of unopened Motul 300 75W90 and 1l opened, all dated 2017. In addition, I have 1l unopened and 200ml opened of Motul 300 75W90 dated 2014.

Any reason not to use any of it? Presumably it's not hydroscopic like brake fluid.

 

Has to be kept in specific temperature controlled cabinet and you aren't allowed to store any other grades of oil with it. (joke)

You should be fine, think about it this way how often is gearbox oil changed, it normally stays there quite close to the weather conditions going through multiple heat cycles.

 

It's been cellared with the Chateau Lafitte, so guess it's good to go.

 

 

As mad as this sounds....we do get mouldy oil if it's left exposed to the atmosphere.

At work we have drip trays, and they get proper fluffy globs of mould growing in like a petrie dish. Even the synthetic stuff.

Point to note engine oil is hygroscopic to a point as it has to handle water that comes from combustion blow-by until the engine is hot enough to boil it and purge out the crankcase breather.

Water is a main combustion by-product (hydrocarbons + air ( HC + O2 = H2O and some other stuff)), of course Greta would like you to think it's nothing but Nox and CO2 that comes out the exhaust, but that's simply not the whole truth. And as they say about Mars; Where there's water there's life. Jim. But not as we know it.


Also another point, sometimes the additives can separate out....so give it a good shake.