Anyone rebuilt front/back differential on 3.0 pre facelift?

[Bmwe5320023.0]

Slowly chipping away at putting my X5 back together, piece by piece.
I had taken everything apart to change all the bearings, balljoints, bushings, suspension etc.

While I had rear diff out, I thought I'd repaint it.
Blocked the sides where halfshafts go in and tried stripping the paint, no luck.

Eventually decided to try sandblasting with aluminum oxide. Worked pretty well, but I guess it was a bad idea, now when I turn the flange at the front, I can hear the noise of the sand...somehow it got inside.
Maybe it's a stupid mistake, it's my first time sandblasting...

I'm thinking of opening the differential to clean aluminum oxide from inside. But I know the differential has to be pre-loaded or it won't last long.

So if anyone has rebuild a differential, any clue where to buy the crush sleeve? I can't seem to find them anywhere...

The other option is to finish sandblasting, paint it and then use some old oil to refill and drain it a few times, hoping all the aluminum oxide will wash out.

What a stupid predicament I've gotten myself into lol!