Originally Posted by x5sportman

My X only has 65K on it, so my sense is that by listening to all four bearings with a stethoscope and finding only one bad one, I'm comfortable replacing only the one. With significantly more mileage on the vehicle, I might opt for doing them in pairs. (I've had other cars go over 150K miles with no bearing problems.)

Having said that, since the bearings are only about $95 each, if you got a break on the labor because you were already in there doing other stuff, it might make sense to go on and get them done. BTW, it cost me almost $400US to get the one bearing done.