Contrary to Item B previously listed: My MB manual states that on air bag equipped models DO NOT use any lubricating grease on the slip rings.
It is OK to grease non-air bag slip rings, but not the air bag ones. I imagine there is concern of either to bag not going off when it is supposed to or deploy going off unintentionally.
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72
'02 CLK320 Cabriolet - wifey's mid-life crisis
2012 VW Jetta Sportwagon TDI...at least its a diesel
Non illegitemae carborundum.