Miele Bearings
We had a 2001 W961 until 2012 or 2013 (I don't recall) which still had ok bearings when it passed away (2nd PCB after 2 UI boards, probably all due to a now - few weeks ago - discovered fault in our houses electric system). It showed signs of bearing aging, but that happens.
Things you hear as a bearing ages can differ, but this generation tends to devolpe that typical vibrating noise. You hear this especially during an empty full speed spin. It is a noise like metal on metal knocking really fast. This happens as the balls in the bearing get smaller and don't sit 100% in place anymore. Ours developed that sound 3 years before it died and still worked perfectly fine till its last day.
Basicly, you can run these beasts till a) you can't stand the sound anymore or b) you can physicly lift the tub by hand. Sounds of aging and broken bearings are completly diffrent. If the tone of the noise gets lower and actually sounds more like a rumble, you should think of replacing the bearings. If it just gets louder, that is normal aging and generally is not a problem.
Mieles usually run around 20 years till bearings actually get bad. But it depends on use. A good factor for a normal household washing mixed loads is that if you run towards the end of your 2nd pair of dampers (which generally need replacement every 10-15 years), bearing failures get more likely.
Replacing bearings can be lot of work on these machines. You do not have to open the tub up like with the old style Electrolux machines (so, AEG, Zanussi, etc.), but you still have to take the whole tub unit out and put it in again. The bearings are located in removable suspension spider on the back of the drum. So you have to take the tub out (means removing weights, pipes, belt, motor, dampers, springs and most likely drawer and housing plus valves), than remove the drive wheel from the tub, than unscrew the suspension spider, knock out the old bearings (there are actually 2), put in the new ones and remove the old shaft seal. At this point, you should decide wheather to open the drum and clean up the whole drum unit plus checking heater and drum spider. If you plan on using it for another 10+ years, I recomend to do so. After you finished that, you place the shaft seal on the shaft, put the suspension spider back on, and than put everything back together. (As you tore into it already, it is a good idea to replace the carbon brushes on the motor as well!)
The bearings plus seals are somewhat like 100 bugs, carbon brushes maybe 30 and work maybe one or 2 days, but it is rather likely that you can use the machine another 10 or 15 years after that.
