The causes of wheel bearings to go bad quickly include improper or not enough lubrication, contaminated or broken down grease, harsh driving conditions, water getting into the bearings, low tire pressure driving on uneven terrain, unbalanced tires and overloading of the wheel bearings.
Potholes, tall curbs or curb bumping can also lead to premature wheel bearing failure.
Wheel bearing grease can break down and even become contaminated overtime if the bearing is not a sealed bearing and especially if the proper grease is not used.
So if your wheel bearings require grease or oil the oil should be changed out after so many miles which is often 10,000 miles or more depending on the bearing.
Grease should also be refreshed in the wheel bearings if the wheel bearings use grease which is often best done every 10,000 miles or sooner if you prefer to do so.
Wheel bearings should last between 75,000 miles to 150,000 miles especially for the sealed wheel bearings.
Wheel bearings that are not sealed and require lubrication by greasing once in awhile can last 150,000 miles or even more.
Although if the wheel bearings are not sealed then they require removal from the rotor or hub either way so I would replace the wheel bearings regardless if they are still good or not.
The quality of the wheel bearings and driving conditions and vehicle modifications also factor into the wheel bearing lifespan.
Wheel bearings that are going bad will start to make noise which could be a grinding noise or even squealing noise is some cases.
The wheel bearing will also start to make the hub lose and when you jack of the vehicle or trailer and you try to rock the wheel back and forth it will move some or a lot depend on how bad the wheel bearing and hub is.
Higher quality wheel bearings and wheel bearing hubs will last longer than lower quality ones.
And proper installation is crucial for preventing premature wheel bearing failure.
If the wheel bearing requires grease the wheel bearing should be greased properly or if the wheel bearing uses oil the hub should have enough oil but not too much oil.
Modifications to your vehicle such as lifting the vehicle, using aftermarket rims, or installing of wheel spacers on your vehicle can also increase stress on the wheel bearings and cause the wheel bearings to wear out faster.
And larger and wider tires can also increase the stress that is put on the wheel bearings and lead to early failure of the wheel bearings and driving on bad roads such as over potholes, speed bumps and other road imperfections can also lead to premature wheel bearing failure.
If your vehicle has wheel speed sensors a bad wheel bearing can also trigger the wheel's speed sensor to send signals to the car's or vehicles warning light dashboard from the ABS sensor or traction control sensor.
Wheel bearings will give warning signs before failing.
Common warning signs of a wheel bearing failure are unusual noises such as rumbling, squeaking and grinding sounds as well as excessive heat and vibration.