Oil

[les]

I’ve done 1200 miles since a gearbox oil change, that was 5 years ago. Should I change it again ?

[philthehill]

No ................
The gearbox oil does not get contaminated with engine crud so in theory it could go on for ever.

[les]

I suppose it was a slightly sarcastic suggestion Phil, re my recent discovery of apparent lubricant lifespan !

[svenedin]

Lubricants do have a lifespan but 5 years is nothing to worry about in a gearbox. If you have ever smelled the vile stench of ancient Armstrong damper oil you would not doubt that lubricants go off eventually!

Stephen

[myoldjalopy]

Does it not get slightly thicker in the gearbox over time?

[SEROWMANMICHAEL]

WHY?

[myoldjalopy]

I dunno, that's why I asked the question. Just something an old-time mechanic mentioned to me years ago..........others here may know the answer.

[olonas]

Morris Motors, in their lubrication chart, recommend a gearbox oil change every 6000 miles. That was using Castrol XL,straight S.A.E. 30, though.

[philthehill]

Considering that the oil is several million years old a few extra millennia is not going to hurt.
Only when contaminates are added to the oil does the need to consider changing the oil occur.

[olonas]

Feel free to leave the oil in there forever Phil.
I will continue to change it. I only quoted Morris Motors own recommendation. What did they know?
It may well be millions of years old but I suspect adding some crude, without refining, to the gearbox might not end well.

[philthehill]

My quote should be taken as a 'tongue in cheek' comment and not taken too seriously.
Even after refining it is still several million years old - so could be classed as S/H.
When I worked in the BMC garage one of the mechanics had a Morris traveller, he used to drain Morris Minor gearboxes, let the oil settle and then use it in the engine of his Minor. He never had any problems with using S/H gearbox oil in the engine and he was very particular as regards the servicing of his Minor.