Product review (5 stars): What a difference!
We were on vacation in a rental house when I one of the dishwasher wheels broke off.  I noticed then that another wheel was also missing.  I was so afraid of the other wheels breaking off so we just stopped using it.  When I got home, I checked my own dishwasher, a Bosch.  One of the wheels was missing!  No wonder it often fell off the track.  I ordered this wheel from Amazon for only $5 or $6 (vs. the $16 it would have cost on the Bosch website with s&h).  The wheel arrived quickly and fit right on.  I have the Bosch dishwasher that was not one of the ones listed, but the wheel still worked.  Bosch only makes one replacement wheel and it's this model.  Now, my rack rolls perfectly every time!