Hi xsvtoys
I write - but it is not a "real help". I like this document: http://rwatts.cdyn.com/download/intro%20to%20bally%20flipper%20games.pdf They say a couple of things about Lubrication - they say a couple of things about "Score-Motor".
I have looked in http://www.pinrepair.com/em/index.htm -> http://www.pinrepair.com/em/index1.htm#lube and -> http://www.pinrepair.com/em/index3.htm#motor - scroll down 6 to 10 pictures and text -> "Lubricating a Score-Motor" -> some words on lubing-GOTTLIEBs (not on Williams / Bally). Scroll down further -> Starting with "Fixing a burnt Motor" -> good information.
Sorry for "not really helping" - but the document (first link) is good.
Also (Williams) -> http://rwatts.cdyn.com/Machines/download_area.html -> Scroll down (below the middle, text "Be sure to check the Links page for additional ressources" -> the fifth link: http://rwatts.cdyn.com/download/wmseman.pdf , good information.
Greetings Rolf