Road block on the way to rebuilding the smog pump! The bearing in the pulley on this particular smog pump is in there permanently. There is no way to replace this bearing as there are 6 crimps to the metal housing that hold this bearing in. This appears to be the variety of pulley that others have complained about costing $500+ only from Mercedes. I may try peeling off the seals and repacking the bearings, but I still have to get inside the pump and change/repack that bearing which is the one making all the noise. The pulley bearing feels notchy from lack of grease and you can hear the bearings rattle if you just shake the pulley.
The rebuilt for $200 is looking better and better.

glenmore
1991 300CE
2000 C280
1990 LS400