It cost me around $200
Wheel bearing?
If you do not change a bad wheel bearing the bearing will cut a groov in the axle.If it goes on long enough the axle will have to be replaced.It could also ruin the axle housing.Then you would have to replace the rearend.
locked-up wheel bearing or one that is about to lock-up.
Check the wheel bearing.
If the wheel bearing was bad enough, the hub could possibly come off. The wheel bearing would have to have been failed for a long time.
There are so many different bearings you would have to state year and name of vehicle to get a good answer.
The wheel bearing should have a inner and outer seal to keep debris out. Do you have these installed everytime you replace the bearing? They are highly overlooked but are the difference in having to replace bearings periodicly.
the same way you would replace any hub assembly, take the wheel off, take off any bolts that connect the hub to the driveshaft and then replace it
to answer this question with would be too difficult to explane, its better to spend the 20 bucks and get the maintenace manual it will show you exactly how to do it
Not knowing what vehicle you have I would suspect the replacement bearings are of poor quality or they are installed incorrectly.
Failed wheel bearing, or the suspension is severely bent.
caliper froze, brake line collapse, or wheel bearing out.