Kinda know what's happened... just wear and tear (can't really be any other obvious explaination), but thought I'd throw it out there in case there's something I'm missing. Both front bearing carriers on my '83 MK1 GTI appear to be the originals, they're certainly genuine VW even they were added later. While back had the local garage press out the old bearing in readiness for giving them a bit of a refurb / new bearings etc. And they definitely did need to be pressed out, which is relevant to what I'm going to write next. Bought Meyle replacements, 64mm outer diameter. Time came to fit them and they just slide through. Inside face of the carriers both come in at 64.2mm which would explain that. Second set of bearings (SKF 64mm) were got just to be sure that the Meyles weren't somehow dodgy and not surprisingly they too slide through with little resistance. I'm aware there are later 66mm and 72mm carriers / bearings though I'm 99.9% certain mine are (or were at some point) the correct MK1 ones. Besides 64.2mm and the next size up at 66mm is a leap. The inner faces aren't showing tell tale signs of wear, they're both perfectly circular and still have a machined finish look to them, not shiney, smooth like you'd perhaps expect if the bearing were rotating in the housings, but I'm just speculating. Like I say, can't really be anything other than wear (cars 165K on it / 40 years old) but what's puzzling me the most is the previous bearings were well seated. And before you ask, they went into the bin long ago, so unable to check them again. Mechanic commented that he'd seen cases of new bearings being cut with grooves / scored around their circumference so that they would take up small amounts of slack caused by wear on the carriers, but again this wasn't the case here. Odd one... unless you know otherwise!
I don't see how the outer casing of the bearing could wear the actual inner facing of the hub. Surely the bearings would just fail first?.? I bought some Meyle for the mk2 and they were junk. Were the SKF the the OE manufacturer, as I think I fitted those to mine and were a perfect fit. What size is the actual hub measuring at?