Amazon: Fluids for my Amazon.

[Derek UK]

Hugh

As per my post above, use the same oil as the diff for the steering box. The way the metal to metal interfaces work is similar, a sort of "smudging" action, so need a tough oil with different additives than a normal gear oil.

[222s]

Depending on the age, make and model non-EP gear oils may be required for use in gearboxes and final drives. Certain designs contained a lot of phosphor-bronze (copper containing) components that are sensitive particularly to the sulphur extreme pressure (EP) additive. The sulphur attacks the copper and destroys the integrity of the meshing gear surfaces.

(From here)

Do Amazon diffs get upset by the additives in modern axle / diff oils or are they ok? I have seen different recommendations in various handbooks about the correct oil, i.e. one saying regular gear oil (but no warning against EP), another saying use EP.

[dgbalfour]

Uh oh, I use EP90...