2006 Ford F-350 front locking hubs

My front locking hubs came out when I went to lock in, it was just the plastic part that you turn do I still have four wheel drive if I turn the selector knob on the dash seeing how I have auto or free or do I have to have the knob basically in the hub to have four wheel drive, they want over $300 to replace the lock out hubs and I do not have the money at this time