Aftermarket wheel bearings are shit. Otherwise something else might be wrong. Like warped Drum causing uneven wear. I'm going to replace my passanger side front for the 3rd time soon as I fix the flex pipe. It only makes a little noise but I've replaced the entire front at this point so I was QUITE so I can isolate any rear issues.I've got an '05 ZX4 with over 100,000 miles on the OEM brakes...but I have gone thru 3 rear wheel bearings.