Thread: Disco diff oils, change or not?

Hi all
Running a disco 2 with 194k on the clock. It comes with service history, but have decided to replace all oils for peace of mind.

I came to change the diff oils today, but on undoing the drain plug, nice clean golden oil poured out! This a good sign or should I change it anyway?.

Also, Guy in Autobarn recommended Castrol Syntrax for 75/90 for the diffs, but this is red in colour, so is it ok to use?.

Cheers

Dave

Originally Posted by Slunnie

I would look for an oil that is also marked as suitable for use in hypoid differentials and extreme use or whatever it is. I think the oil code is GL4. These oils have better lubricity/sheer strength.

GL-5.

GL4 is an obsolete spec that has 1/3 less anti-wear (AW) and extreme pressure (EP) additive levels than GL5 lubes, although GL4 is often cited as a spec in relation to manual gearbox oils.
GL5's are formulated for hypoid diff use.

.....and Syntrax is a GL5 that has a copper corrosion rating of 1b with additives to ensure reliable synchro use for transaxles, eg t/cases with synchros and manual gearbox use requiring a 75W-90 lubricant.
It's very good for a reasonably priced and very available full synthetic lube.

BTW, the colour of the oil is just a dye, most are near colourless when blended.