If I remover correctly, it’s more a grease than an oil.
Somewhere there’s a document by a forum
member by the handle of ishipaco.
The gist of this document is that the
gearbox oil/grease should never really need to be changed.
I had a
rebuild kit with the unit I had. There were two tubes of grease, a small one of silicone for the o-rings, and a larger one of a normal axle looking variety for the
gear case.