> I have a very basic question -- what does hypoid mean? Also, I have
> been told not to use gear oils with high sulfur as this will degrade
> the coatings on the tranny components. Is this an effect which
The problem with using gear oils that contain sulfur in your
transmission is that it reacts with the copper in the brass synchros.
It's like putting the rings in a weak sulfuric acid solution.
> usually takes place only at operating temps or did the 3 months of
> room temperature contact with Sta-Lube 90wt already do its damage? One
This reaction is relatively slow so I suspect after only 3 months
you're okay.
> last question, how do you know if a gear oil contains sulfur -- is
> this related to "hypoid"?
The designation Hypoid does indicate that the oil contains sulfides,
but you can confirm this by using your nose. Hypoid gear oil has a
distinctively pungent odor. Actually, hypoid refers to the gear type
that the sulfides additives are formulated to help lubricate.
> Now, here is my contribution to the debate -- it was suggested that a
> 20W-50 synthetic motor oil (syntec or mobil 1) could be used in a
> tranny. Then it was suggested that this wouldn't provide enough
> friction for the synchros. I'm on the digest version, so excuse me if
> this has been suggested, but how about Motul or a similar synthetic
> motorcycle oil. These oils are made with an enhanced additive package
> -- most important to this discussion is additives for shear viscosity.
> Since in a motorcycle (usually) the oil lubricates both engine and
> tranny, something like Motul might translate well to an auto gearbox.
Why not use an oil (synthetic or otherwise) formulated specifically for
use in a synchromesh transmission?
Roland
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