Wheel bub bearing assembly.
Wheel hub bearing assembly keeps your wheels rolling with very little friction.
The engine transmits power from the engine to the transmission transfer case. Axles then transfer the rotary motion from the transmission to the wheels. The hub assembly is mounted in the knuckle which also has wheel studs which secure the wheel.
Wheel bearings can be made up of round balls of steel or rollers. Wheel bearings can last upto 80,000 miles. Wheel bearings are subject to great heat . Wheel bearings are sealed with a seal to retain grease which lubricates the bearings.
Over a period of time the grease will loose its properties or leak out of the seal. Wheel bearings can also wear out due to friction and heat and will need replacement.
A bad wheel bearing will cause a rumble and the noise will be constant while driving on a straight road. A noisy wheel bearing will stop making noise when you make a slight right or left turn depending on which bearing is bad.