Mac 400k floppy drive alignment?

[Josh Dersch]

Got myself an ancient external 400k mac floppy drive on the cheap that 
I'd like to use on my 128k mac -- after cleaning out the old dried 
lubricant and getting the drive mechanism running again, the drive works 
but will only read/write disks that it has formatted, which leads me to 
believe that the drive is out of alignment.  How is alignment corrected 
on these drives?

Thanks!
Josh