75w90 name brand gear oil. some come with the clutch additive already in it, if not the dealer ship has it. As for synthetic Eaton says not to use it, to slick for the clutches to work properly
PS I can't remember how much it holds, but I think it about 2qts. I just put the additive in then fill it till it starts oozing out.
Last edited by richard stewart 3rd; 06-24-2011 at 02:51 PM.