Umm, say what? There were only 2 response posts at the time, mine & Gary M’s - barely enough for a “Hi Opal” list.
In addition, when I read Gary M’s post, I figured he was going further than my initial statement (that the car body is simply held on the truck bolster by gravity and aligned with the bolster pin), and was adding the fact that the truck sideframes are, in turn, supported by the wheelset axle roller bearings via gravity; they are not bolted or welded to the sideframe (again, this is modern N.A. freight truck practice).
Here is an stock image of some stored wheelsets; Note the roller bearings already installed. Those bearings fit into the sideframe pedestals (in those ‘notches’ in the sideframe), and a wheel bearing adaptor goes between the pedestal top and the roller bearing, such that the sideframe rests on the bearing adaptor, and in turn the bearing adapter rests on the roller bearing (OK, it’s a bit more complex than that). Yes, everything seats and items are keyed, but gravity does the real work. Here’s a page concerning inspection of roller bearings with some images that may help.
So that machine elf can feel relieved, there are some bolts involved in keeping things together beyond the roller bearing end cap screws: there are metal pieces at the bottom of the sideframe pedestal called bearing retainer (frame keys), which are designed to keep the sideframe with the axles if the sideframe skews up due to…a derailment. Otherwise, they should play no roll in normal operation.
So, sorry TriPolar, old chap, your facetious post was a very bad show indeed.