Yes it does lol. Don't use wd-40, get bones speed cream or something. Depends on whether you have oil or grease bearings though, in which case use the same kind of grease you use for your headset.
dude. set of 2 full on Si3N4 ceramics for 10 bucks? That's such a good deal that I picked up 2 of the 5 that they had hop on this if you think you need new bearings.
I know, I said "set of 2". 2 sets of 2 = 4, enough for a scooter, which is a damn good deal considering they're probably the same if not better quality than bones ceramics, which are 60-80 bucks a pack.
NO wd40, it will attract more dirt... happened to my friends skateboard, buy 3to1 lube at a hardware store, its the same as speed cream but wayyyyyyyy cheaper