Oil shelf life?

[Rynglieder]

Sorry if this is a stupid question, but it is by asking stupid questions that I learn stuff...

How viable are oils that have been on the shelf for a long time?

I want to replace the shaft oil in my GTR (Hypoid 80-90) and I have some in the garage that has probably been there (without exaggeration) for decades.

Do you think it would be safe to use or should I go out with the last of this week's pocket money and get some new stuff?

The bottle that I have has always been resealed and should be uncontaminated.

Thanks,

Pete.

[GSXKING]

Do you own or know anyone with a spectrometer Stan ?
That would identify its viscosity and give a fair indication of its usefulness 👍
If it were me I'd buy new 🙀

[Chrisl]

No question, it's a new bottle for me !

[Pommeroy]

I'm with ChrisL and would use new oil.

Many oil manufacturers suggest using oil within a year after the container is opened, and in around five years if unopened. "Decades" and repeatedly opened...I'd biff it out.

[KiwiCol]

You don't need much oil for that, 220ml, so a 1L bottle would do 4 final drive changes.  Yeah, you could probably use the stuff you've got on the shelf there, it may be ok, it may not, but, my take on it is, you use this machine to do your European trips, it has to be reliable. 

If you used the old oil in the final drive, you may (I would) be forever wondering if you were slowly destroying your diff and bearings in there. For peace of mind you've done right by the final drive, spend the few quid on a new 1L bottle of 80w/90 and your mind can rest easy, your wallet isn't going to complain much either for a 1L bottle, prob cost less than a couple of pints.

Happy travels Pete.

[gsxbarmy]

Yep new oil it is - oil only lasts 2-5 years before it can degrade

[Eric GSX1400K3]

Oil ages, it reacts with the atmosphere and oxidides, regardless of whether the cap is on or off, once the original seal is broken, air gets to it. Oil technology is evolving too, the additive packages get better, e.g anti foaming, anti coagulanrs and friction modifiers etc.  Go with a new bottle, your final drive will thank you for it.  As said a 1l 80W90 will do.

[FlyWheel]

New bottle for sure.
I've a few almost empty bottles of gear oil sitting on the shelf too. When I next do a change on the wing, it'll be new bottle. As was mentioned, more for peace of mind. If you love your bike, give it the best you can, within reason 

[grog]

Get some new stuff use old stuff as chain lube👍

[Rynglieder]

Thanks gents, after doing a bit of searching most manufacturers seem to quote between 2-5 years unopened, so I've already pressed the button and there is a bottle arriving from Amazon today along with the new 10-40 for the engine.

Before that arrives I have to undo about 50 bolts and screws on the fairing to get at the coolant reservoir.

It used to be easier when I paid someone to do all this stuff...

[Chrisl]

I may get shot down for suggesting this, but
Would it be ok to use the old oil for lubing the chain ?

[KiwiCol]

I may get shot down for suggesting this, but
Would it be ok to use the old oil for lubing the chain ?

Yep, absolutely.
Quality modern chains have "O" rings or "X" rings to seal the factory lube in and to keep dirt & water out, so when you clean & lube one of these chains you're just doing the outside bits.  The oil you use isn't (or shouldn't) be getting past the sealing rings. Aggressive solvent type cleaners can get past the sealing rings and 'wash' out the factory lube, that's when you get tight links. The solvent cleaners can also swell or harden the sealing rings and they fail that way too. 
I recall I had an RK chain I put on, didn't last long, all (lots anyway) the O rings were breaking and ending up on the floor under the bike, & it was a fairly new chain, not abused in any way, they were just no good, even with being oiled.  Think RK had a bad batch of chains at one stage, but I never went back to them, stuck with DID VMX530 or whatever it was.

[grog]

my chain that seized a link was RK, mustve been part of that bad batch.

[Barbastro K6]

For peace of mind I suggest  Redline 80W gearbox and cardan full of ester and overflowing additive package.