I don't remember ever working on a bike that needed the axle to be installed in one direction or the other . . . . having been to a couple of motorcycle assmbly lines, the direction of installaion seems to be based on ease of installtion on the line (which includes the side the assembler is standing on) . . . .
Put it in either way (I generally try to put the securing nuts on the same side -- makes it easier to check for the presence of the angle clips I tend to use).
Searching for the immaculate contraption