Same thing happened to me over the holiday with my '86 300E. I did not know these could fail so suddenly. Made a huge racket. The car was towed 205 miles to Salt Lake. The bearing(with bracket) and fan pulley were replaced. Fan clutch was ok. Total cost was $350. It was an independent shop, I am sure they used aftermarket parts.
I guess I can't be too upset. The first thing that went through my mind when the bearing failed was "My timing chain just broke!".
All fixed and running smooth.
Blake
'86 300E
246,000 miles