update to papers


Staff member
Jun 5, 2002
Iowegia - USA
I don't think I would make sweeping generalizations such as this one:
Synchromesh transmission oils General Motors, Honda and others have developed oils that combine the best shift characteristics with their transmission components for reduced wear. These products in general could classify as GL-4 oils if they wanted to, but actually when we analyze their components they are very similar to 5W-30 diesel motor oils, with a few friction modifiers added. The viscosity is closer to an ATF. They are way too thin for a Corvair transmission or any other where a SAE 80W-90 or 75W-90 is recommended. I will explain the viscosity differences below. I have added the viscosity curve and characteristics to the graphs. Note: just about any diesel motor oil can pass the GL-4 gear oil ratings.
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