S2 hub surface machined. Why?

[M2ki]

Bought a pair of S2 sedan rear hubs and discovered after cleaning that someone has machined that area which meets with brake disc.
Why would anyone do something like this, is this somekind of a mod for different discs?
There is 0.4mm slop between the disc and hubs. Original has 0.05mm slop.

[_ShurikeN]

Someone might have just roughly resurfaced hub if it was way too rusty. It could be some sort of adaptation for a non-original brake disk. And at last: aren't they machined UFO hubs pretending to be S2 ones?

[rxl]

s2 sedan? dont look like oem parts

[M2ki]

Someone might have just roughly resurfaced hub if it was way too rusty. It could be some sort of adaptation for a non-original brake disk. And at last: aren't they machined UFO hubs pretending to be S2 ones?

Part numbers are OEM S2 sedan/avant rear. 82mm bearings.
8A0501653A
They are not machined any other way. And the surface was not that rusty, factory maching marks were still visible.

[rxl]

look for for a audi logo and casting number on the hub itself and not the carier.

[_ShurikeN]

It's a hub partnumber indeed, not hubcarrier number.

[M2ki]

Number 8A0505435CD on the hub carrier seems to be casting number not part number, as all the B4 & B5 quattros have the same number on the carrier, doesn't matter if it is 75 or 82mm.
82mm hub carrier part numbers are 8A0505427D & 8A0505428D

[spink]

Someone might have just roughly resurfaced hub if it was way too rusty. It could be some sort of adaptation for a non-original brake disk. And at last: aren't they machined UFO hubs pretending to be S2 ones?

ufo hubs look nothing like s2 hubs

[_ShurikeN]

ufo hubs look nothing like s2 hubs

Only when not touched by a machinist proper way. You will be able to distinguish my UFO hubs installed in place from genuine S2 hubs only by tapered hole for brake disc fixation.

[M2ki]

You will be able to distinguish my UFO hubs installed in place from genuine S2 hubs only by tapered hole for brake disc fixation.

You are using UFOs in the front or rear?

[_ShurikeN]

Used to have them on the front. Now they are on another audi 80.
They can be applied at rear with big bearing, but the track becomes wider.

[varia]

in the states, V8 UFO rear hub is the same as the urs4/6 front. they work but wider, however C4 100/A6 quattro rear hub has the same offset as the S2/CQ (its still needs to machined like 5mm) and works well on the CQ

[90/90qs]

Maybe the PO was running calipers that needed a rotor offset adjustment. If they added a spacer and removed some hub, that would save having to go the alternative route: custom brackets.
-doesnt seem like the best engineering idea, but the only rationale that comes to mind