Back in the olden days (maybe 20 years ago), lubrication getting old could be a problem, but I haven't see that in years now.

I can remember customers who had big full height 5 1/4 drives that wouldn't spin up after being shut down over night. The motors didn't have enough torque to overcome the hardened lube. Manually rotating the drive around the disk axis would break the disk loose and then they would spin up and work. Of course, the recommendation at that point was to not shut down the drive until everything important was backed up, and preferably the drive replaced.