Diff oil

[smunro90]

Does any one know what grade oil ill need for my 4.10 small case open diff for my m42? Thanks Stuart

[Mikey_Boy]

Anything that's 75W or above should do you, max viscosity 90W. For the love of God don't put ATF into it!!

[smunro90]

Okay thanks any preferred make?

[Mikey_Boy]

Castrol is the official stuff I believe but anything from Opie or Miller will also do just fine. Capacity is around a litre (basically until you can't fill it any higher using the level plug, not the drain plug obviously!!)