I just bought a 1972 Mustang Coupe (V8, 302, front & rear drum brakes). I was able to remove the front drums. I cannot get the rear wheel brake drum off. I have backed off the shoe adjuster and the wheel spins freely ( I don't hear the shoes touching the drum at all). It feels very tight and solid. I cannot move it or wiggle it at all. What the hell is keeping it on the car?