When I first pulled drums to rebuild, I found no wear that would cause a lip.....so just went on with things. Unfortunately, I did not really clean up the rust and crud on the lip. So, I just pulled the rear drums for Ebrake work, and they would not come off. I had to loosen the adjuster about 3/4 to 1 turn. So, I have now taken a sanding disc and removed the rust and crud in the hope that next time they may come off. Yes, the adjusters tighten things up pretty good, but since they turn, they should slide.....so here is hope. Just something to consider for future work.