Outer Limits 4x4 Board

i was wondering if Extreme pressure oils are bad for sierra's? I dont actually know what the difference between the oils is but i found a brand new 4 litres of Castrol 80W/90 EXP gearbox and diff oil in my old boys shed that he said he didn't need anymore and wanted to know if its useable? good? bad?

Tosh

if you read the back of the bottle it says "suitable for vehicles where sae grade 5 oils is recomended" so it should be ok for a sierra.

yeah i read that but had no idea if those oils were suitable for sierra's. Thanks

Tosh