Colour of Oil

[Lobo]

Changing gear box oil today (car) and using last of year old bottle, followed by new bottle - both same manufacturer / type / spec. The new bottle however, almost clear in colour versus the older bottle @ amber. Notably both labellings identical, and state the colour as ‘Amber’
Both feel ‘slippery’ to the touch for sure.
Anything of concern here pls? Ta.

[Rozabikes Tim]

Drink more water if sample on the left!

[McCabe-Thiele (Ted)]

Oils tend to darken over time due to oxidation the rate depends on storage condition such as temperature & how much air remains in the container plus the amount of moisture in that air.

I would expect synthetic oils to be more stable over time.

It would be interesting to know if agitation by shaking changes the colour of the sample taken as I would expect some layering to take place whist it's on the shelf.

PS Should still be okay to use.


https://en.oelcheck.com/wiki/change-in-colour/

[Athame57]

Drink more water if sample on the left!

[Lobo]

Never considered shaking it Ted, but tbh drained both bottles and those colours constant in each, and no residues remaining. I’ve used this oil for 5 years now, and up until now it’s been the amber colour irrespective of length on my shelf. Interesting…

[McCabe-Thiele (Ted)]

It could just be a batch difference during manufacturing or even a slight change in specification - might be worth contacting their technical department if it's worrying you.

When I changed the rear diff  oil in my W124 300TE 4-matic Estate the old oil came out looking like back treacle - I remember vividly it as the smell was just awful.

[Bryanj]

The oil drained from Leyland coach torque convertes always smelt like rancid gnats piss

[K2-K6]

I'm with Ted on the cause likely being just a little oxidation as difference between the two sample.

Doubt if it has any real effect as the service life of GL5 spec could easily be 100,000 miles in a plain differential, there's no other outside influences to contaminants.

Think that GL5 spec increased the sulphur content as it gives friction/longevity benefits to gear sets in service. Probably enough sulphur to preserve a horse  and why EP oils have that predominant pong even when new.

[Johnny4428]

The oil drained from Leyland coach torque convertes always smelt like rancid gnats piss

😂😂😂
Going to take a lot of gnats to make any quantity!