new bearing started failing after 3 weeks

I replaced the passenger side bearing/hub assembly 3 weeks ago and I have noticed that it is starting to fail already. I'm wondering if the part was defective or if I had put it on wrong? I don't really know how I put it on wrong as it's only a couple of bolts. Could someone please let me know if I could have installed this wrong, or if there may be another problem with this car? Also, how hard is it to change out the cv joint in this car?

First thing I would suspect that would kill a bearing so quickly is possibly the axle nut being torqued incorrectly. If it was over tightened that could cause premature bearing failure. Did you replace the nut and torque it to the proper value?

Thanks, that sounds like it might be the answer. Would loosening the nut help, or do I need to replace the bearing?

I agree. I'd say alot of the premature failures we get on hub/bearings is either due to improper torque, installation or brand. Also, hub makers may specify their own torque value which will preempt the FSM specs.

Typically for '99-'04 Aleros to include Grand Am there are two different axle nut torque values depending on which axle nut you have. There are two designs. 1st and 2nd. The first design axle nut is a PAC type nut so the torque value is 284 ft-lbs. The second design axle nut which is a gray color is torqued to 173 ft-lbs. You are not supposed to reuse a PAC nut if you have that installed.