Anything I should do when getting new rear disks put in?
They have a gooey stuff on one side, is suppose I should clean that off. Should they be just cleaned and installed? Or is it better if they machine them once?

 

you need to clean that stuff off before installing. i used alcohol then used some real fine grit sandpaper, just enough to scuff them a bit. remember to take it easy the frst time you drive it. no hard stops. the stockers will glaze faster than a krispy kreme.