I've seen that weight of which you speak and always dismissed them as a balancing weight. I can't imagine what would cause the kind of damage you're describing. To tear the backing plate is way more than the typical rotating wheel cylinder. The only other suggestion I have is to be sure the parking brake cable isn't sticking and holding the shoes away from that big anchor pin on top. You should be able to push the parking brake strut bar a good 1/8" against the pressure of the anti-rattle spring. If a sticking cable is causing the shoes to be held away from the anchor pin, the shock from when they grab the drum might be what's pounding the backing plate apart. Even that would be unexpected as it happens to a lot of cars without tearing it up. Gee whiz, tires lock up and skid all the time without causing that kind of trouble.
Shoes will grab real hard too if they're contaminated with gear lube from a leaking axle seal. Same thing though; that too shouldn't cause the kind of damage you're getting.
Saturday, August 28th, 2010 AT 11:11 AM