[Sentoa] Transmission Fluid

[Mark & Susan Perlick]

After having spent over 30 years in GM automatic transmission engineering, I
have some background in the ATF question.

Dexron (not DexTron, which is a common mispronunciation) is a specification
driven mainly by GM through the SAE (Society of Automotive Engineers) Fuels
and Lubricants committee.  There have been several versions of this spec
beginning with the original Dexron, to Dexron II, and Dexron III.  Besides
anti-wear additives, anti-foaming additives, etc, a primary additive package
affects friction characteristics.  This is important both for torque
capacity and shifting characteristics.  Transmission seals and O-rings are
also sensitive to improper additives.  Oil companies produce the base stock
and then mix in purchased additives.

Our boat transmissions are probably not too sensitive to variations in these
factors, but there is no reason to risk using non-Dexron spec ATF.  Dexron
fluids are legally licensed to comply with specifications but there is a
black market for non-complying fluids.

My recommendation is to use name brand (big oil companies) ATF certified on
the label to meet Dexron II specifications.  Buy it at an auto parts store.

Mark Perlick
Steadfast NT37-050