Does anyone know of a good web based cross reference for lubricants? I deal with equipment from European and domestic suppliers. So cross referencing from one lubricant manufacturer to another is a frequent task.

You could start by lubricant manufacturers websites like:
http://www.amsoil.com/lit/g1378.pdf#search='Lubricant%3B%20cross%20reference'

http://www.ultracheminc.com/cross.asp

http://www.ccoilco.com/webpage/crossreference.html

http://www.selectlubricants.com/

http://www.ecompressedair.com/lubricant/lubricant_cross.shtml

Our lube supplier is Chevron/Texaco and the rep provided a list that not only cross referenced other manufacturers lubes, but also compatibility. One thing that must be verified is the compatibility of the different lubricants. If they are not compatible, it can cause serious problems.

Gary B