My 2004 f150 fx4 rear axle seals started leaking. I replaced both of them and the driver side still leaks. Are there any fixes besides a new axle ? I didnt think it looked badly worn

 

If there were no scratches or wear where the axle seal sits, its possible the seal was damaged during install.
its good practice to pack grease in the back side of the seal when driving it in to prevent the spring from falling off.

I would take it apart again and look closely.

 

You may need to replace the bearing also.