The o-ring came in and everything is in place again. I took it for another neighborhood drive and it feels great ... but I am getting an awful scraping sound from back there now, accompanied by a very high-pitched squeak, both at wheel speed. It sounds to me like it's the dust shield or the parking brake causing it, although it's extremely hard to tell because I can really only hear it when I'm passing parking cars or buildings fairly closely (I guess it resonates). I couldn't hear any scraping from the wheels when I turned them by hand, but I'll play around with it later. Anything else I should be worried about that would cause a scraping in time with wheel speed?

__________________
1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)