1. There is no fixed replacement time for the wheel hub bearing of an automobile. As long as it is not damaged, it does not need to be replaced. Normally, the wheel hub bearing is replaced every 100000 km or so. However, this depends on the road conditions and environment of the vehicle. If it is well maintained, it does not need to be replaced until the vehicle is scrapped.

2. Generally speaking, the hub bearing should be inspected after 50000-80000 km. If it is found to be damaged, it should be replaced. If it is not damaged, it can still be used normally.