[Gazwould]

I would use Fuchs TITAN Sintofluid FE SAE 75W.

 

[Gazwould]

You use 5W30 engine oil in place of a 85W90 gearbox oil ?

 

[Gazwould]

That's all down to the sulphur levels hense why gearbox oil stinks .

GL4 isn't going to do anything to brass / yellow metals , GL5 have more EP additives and some are aimed at manual transmissions and some GL5 have more and are aimed at purely at diffs etc .

 

[Gazwould]

I would .

To my recommendation , very few here will understand , centiStokes , additive package , grade , W , tungsten disulfide , oil basestock groups , sulphur , EP, severely hydrocracked mineral , pure lab produced synthetics , esters etc like I do..