That part number is for the pinion seal in the differential.

It's called a centering cone, sleeve, or bushing. The FSM calls it the centering sleeve. It can be removed and replaced.
You drill a hole through it then put a metal rod through the hole and drive a wedge between the flange and the rod.

Here are two pics of the one in my 240D when I bought it in 05.
First pic is the way I got it after the PO blew out the flex disc.
The second is the replaced part.

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