Went to replace my pinion seal back in oct as some finial wrenching on the car for the year and after I got the drive shaft off I went to check the preload reading on the rear end with an inch lb torque wrench but I had 0 preload on the rear end. I did this with the brakes off b/c they were dragging on the calipers. When I did take the pinion nut off the flange just fell off when I thought and was told that I would have to hammer it off. So my question is what do I do from here? Is there substantial damage to the rear end as far as having to rebuild it with new bearings? And what would cause a no preload reading on the rear end?