Quoting James <nyb@xxxxxxx>:
>
>
>
> >Dick, I think the main advantage of the whale oil along with many animal
> oils is
> >the organic acids that react with the metal surface and form an oxice layer
> >that is far more resistant to adhesive wear.
> >
> >
> You sure about this one D^2? What are the internal components of a
> transmission made of? Not all metals and alloys will form stable oxide
> films. In many cases, (iron comes to mind) you would have metal
> dissolution long before a barrier oxide.
James, I take you are a chemist. May be the "oxide" is not the proper
terminology, but yes, I there is a chemical reaction of the additive with the
surface metal that forms a layer of some compound (may be not an oxide) that is
more resistive to adhessive wear. Yes, the additive type is sensitive to the
type of metal. Extreme pressure additives for example are generally designed
for ferus merals. The old animal fats were as said, weak organic accids. The
modern additives are lead and zinc based, but there are large variations for
different applications. Again, these are rellevant when there is a lot of
metal-to-metal contact. The engine bearings for example that operate w/out
contact once started, are not affected by the additives.
Al will form a barrier film,
> and it would not surprise me if many transmission components are made of
> Al, but I'm skeptical that the conditions you suggest would cause Al's
> natural oxide film to thicken and/or increase in hardness. I have seen
The friction materials of the transmission are weird. One end is certainly
steel, but the other end is a specified friction material that is probably a
mixture of stuff, just like brake pads and shoes. My guess is that the ATF
additives are tuned to what type of friction materials each type of
transmission uses. Sometimes, in an auto transmission, you want high friction
to ensure a proper shift, while you still want to protect the thrust washers
and bearings from start up wear. So, the additives will have to work with the
friction materials one way, and with the bearings another way.
D^2
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