I've spent a week researching what gearbox oil to use in the gearbox. What a mine field this is. There are different specifications of lube that are suitable for certain applications. Ok, that makes sense. But if you use the wrong one you could ruin your gearbox. For instance, certain chemicals in gl-5 transmission fluid can oxidize yellow metals such as copper and brass...aren't some bushings made of that? So I have all the manuals ford created for the Fiesta: Shop, Haynes, owners. And the only specification I can find is Ford Spec ESP-M2C83-C. None of the auto parts stores that I talked to could cross reference that with their oils. I went to the local Ford dealer and they didn't have a cross reference in their computer either. Finally the parts guy dug up a note about "Motorcraft Full synthetic manual transmission fluid" is now the recommended oil for the IB5 gearbox and older manual transmissions requiring GL-3 and GL-4 grades. It costs $21.31 a quart. It requires 5 pints or 2.5 quarts.
Haynes manual say it requires SAE80 EP. Castrol product is Hypox Light... I don't see it in the US, but the UK has it at a classic car site.
http://www.holden.co.uk/displayproduct.asp?pCode=090.917
Here is what Castrol US has to say: Manual Transmission
NO MATCH
EP 80W - "WE`RE SORRY, NO OIL RECOMMENDATIONS ARE CURRENTLY AVAILABLE FOR THE VEHICLE YOU SELECTED. TO RECEIVE FURTHER INFORMATION AND POSSIBLE RECOMMENDATIONS, PLEASE CONTACT OUR HELP DESK AT (800) 462-0835"
I can't believe that, of all things on a 33 year old Fiesta that could prove difficult to find, it was transmission fluid.
