[lovehamr]

After Mike at Iconic parts and Brian at Vintage both returned my emails, the hub assembly went together with no more hitches. That piece above is a spacer that goes between the stub axle, which apparently is a V8 Audi piece, and the hub bearing which is a beemer part. That's why none of the BMW how to videos or write-ups mention it. But it bridges the gap so to speak between the broach cut beemer bearing and the radiused Audi axle.