What makes wheel bearings/hubs wear out? 1998 Chevrolet Malibu hubs going bad...

[Alexander T]

...after eight months!? About eight months ago, my girlfriend's front wheel bearings/hubs on her 1998 Chevrolet Malibu started making grinding noises. The mechanic said that it was the front hubs, so I had them replaced with aftermarket (read: cheap) ones and the noise was gone. A dealer OEM replacement and repair would have run me $650, but the aftermarket pieces only ran me $80/each, and labor was about $150 (iI think). Eight months later, or about last week, the hubs are grinding again.

I am in Minnesota, so I was thinking that maybe it's partly due to the weather and the road conditions, but eight months, even for an aftermarket hub, just seems a bit ridiculous. If it were up to me, I'd sell the car and get another one, but it's my girlfriend's car, so it stays (and I'll wait for the repairs to keep piling up).

The hubs took about 9,000 miles before going bad.
I bought the hubs on my own from a nearby O'Reilly Auto Parts store.

 

[Ivan B]

some aftermarket bearings are junk. i've seen this numerous times. if your not going with OEM GM parts then replace them with ones from reputable parts places like napa auto. and ask what kind of warranty they have. also be sure they are installed by a trained professional with the right tools, because they can be damaged if not pressed in properly.also be sure the wheels are balanced, because vibration will significantly shorten the bearings life expectancy.