*shrugs*

Ran some off the shelf Castrol 80/90W.. after about 50km's the diff started to make some REALLY bad *tonk tonk* noises. It was fairly violent and people up and down Southport St in Leederville started looking at my car as if it were some bat out of hell.

I continued with it for another few days until i figured that a Cusco Diff should really use Cusco oil.

Diff was fine ever since, quiet operation, binds up nicely.

I'm all for finding cheaper alternatives , but that's just my exp with oils with this Cusco 2 Way RS unit.