I've never gotten all the way to the axle, my trucks always end up breaking or fucking up somehow before I could even get close to grinding em down to the axle, so I replace em.
And I think i might be the only person here who actually doesn't mind breaking in new trucks. It's really not all that bad. I will admit though I hate it when I break a set of trucks just as I get them feeling right and turning the way I like em to.