Iron Horse said:Sorry , not correct . The outer shaft bearing will run dry if the oil level gets that low especialy when it is elevated whilst mowing slopes . As for the breather , i have made them before for other aplications . If it still throws oil out it is a simple matter to scrunch up some bird wire and place it in the pipe which stops the oil but still allows it to breath . I drill an 1/8" hole crossways through the bottom of the pipe and Braze a cross bar into the hole to stop the mesh from dropping (a piece of Brazing rod works well for the cross bar ) When you need to refill the box you just need to unscrew the pipe .
I would have expected a half decent design to include some sort of oil slingers to get the oil out to the ends of the shafts.
Mayhap we're just talking early 20th century ag-tek here, so maybe not.
OK, so it has to be at least up to the bottom of the uphill seal, worst case that probably means FULL !
I was referring to the Caroni gear box atop the mower, not a lot of height difference in that little box when its tipped side to side.