Cautionary wheel bearing info
 

When I bought my 05 3.0 about 15K miles ago I thought I heard a bit of bearing noise from the L/F. The tech thought it was tire noise and we spun it in the air and felt nothing.

The noise got just a hair worse over the miles, and yesterday the dealer tech did in fact diagnose it as a bad bearing and it was replaced under CPO. The noise went away.

Evidently, the X bearing made noise because it was defective, rather than failing catastrophically because of lack of grease or actual broken or rough parts. My guess is that it may have been built a touch loose, enough to make noise, but not actually broken or worn out enough to just grind to a halt in any dramatic way.

So, these are sometimes hard to diagnose on the X. Spinning the wheel is tough because of all the drive shafts, differentials, etc that keep it from really spinning "free". Still, I could not feel any roughness or play at all.

So, if your X has that subtle sound, one that changes in corners but doesn't change on different road surfaces, then think bearings. Don't expect that the symptoms will be dramatic, at least for a long time. It is hard to diagnose and would be even more difficult on Xs with big low profile aggressive tires.

BTW, they replace the hub and bearing, as well as the usual seals, etc. The parts are listed separately, so it is not an assembly.

Mine failed at 31K and were replaced under warranty. The giveaway was a "clunk" when turning the steering wheel while backing up.

when would be a "good" time to replace the wheel bearings? on my american cars, I'd have it done at 50k. on my X5, I'm at 105k and have just thought about it just recently. But then, it all depends if BMW uses aircraft quality bearings vs automobile bearings typically used in american cars

Interesting. Did the "clunk" happen all the time or just some of the time? My "clunk" while backing up happens intermittenly, but usually with the wheels turned at a pretty good angle.

Control arm/thrust arm bushings are new so that's not the source of the clunk. I believe that the sway bar links are newish too, but I have to check them.

I have an Inspection II coming up in a couple of months so I am curious what to state to get the wheel bearings looked at (if it isn't the sway bar links).