automatic 4x4?

i have 2000 f250 7.3L super duty powerstroke. it has the 4x4 lever on the floor and it had manuel hubs. but it was converted to automatic 4x4 still using the lever on the floor. so my question is does it matter which was i have the knob on the hubs turned?? i have tried it both ways and 4x4 works either way. i am wondering which way they need to be turned so im not wearing out the hubs?