just got a complete break job done on my 2012 silverado and noticed a weird almost jerking noise from rear drums. So i looked at them and noticed one has like a half circle cut out on the outer edge of drum and the other has like five inches like it was routed out . Is that a normal thing that a mechanic would do? thanks

 

pan out...can't tell what i'm looking at.

if your getting noises after work was done...bring it bake and test drive with the tech. If its related to their work; they will correct it.