While trying to find where the heck I could get a 90W GL-5 gear oil for my 2003 F-350 I ran across this site.

http://www.fcsdchemicalsandlubricants.com/supplier/

For some reason Ford spec'ed out a 90W gear for the front diff on my truck. Seems this stuff is only available from Ford and in synthetic form from Royal Purple (if your willing to buy a 5 gallon drum of the stuff that is).

Also found this handy axle lube chart

http://www.fcsdchemicalsandlubricant...f/axlelube.pdf As well as this little tid bit of info:

http://www.fcsdchemicalsandlubricant...and%20Steering

Approved by Ford Engineering for use in all passenger cars and light duty trucks which originally specified SAE 90

Lots of other good stuff on this site as well such as MSDS info and part numbers.

Oh yeah, and for you folks that are stuck using 5W-20 stuff, seems Ford also makes a fully synthetic version as well.

http://www.fcsdchemicalsandlubricant...ry=Motor%20Oil

 

Very interesting site, Motorcraft also supplies a 0W-30 syn blend motor oil.

 

I'll agree that the site is interesting. Seems that per MSDS the "full" synthetic is only >60% Gp III, > 5% Gp II, and >5% napthalene. They don't bother to state the rest of the material used in the formulation. While it is a great oil per analysis, this certainly didn't show much. I believe that you will find that the synthetic blend and the oils bottled as a "full" synthetic are the same. This pretty much mirrors the composition of the Blend. Either way, it is a great oil.

For you Flashpoint junkies: COC method- 440F