Vwdiesel Digest, Vol 20, Issue 5Hi Hagar, Look here: http://oil-store.com/OilStore/API%20Gear%20Oil%20Info.htm http://www.lubrizol.com/ReadyReference/DrivelineLubricants/15-gears/lzgearclass.asp but, just because a spec is obsolete doesn't mean nobody makes a product that meets those specs. Ron Hagar asks ? what does it mean that GL-6 is obsolete ?.