[VAC] Re: Synthetic transmission oil

["Carol and Oliver Filippi" <ofilippi@xxxxxxxxxxxxx>]

Jack,

I think Harvey makes a good point.  Good synthetic lubricants are
characterized primarily by their stable viscosity (over a wide range of
temperature), lubricity, and resistance to breakdown from high heat.

Other than the lower friction (lubricity) characteristics [which are
significant where moving parts rub aginst one another (as in bearings and
piston rings sliding in cylinders, etc.) but probably not that important in
an automatic transmission]  fresh conventional transmission fluid should not
be at a big disadvantage  IF 1) you change the fluid and filter frequently,
and 2) MOST IMPORTANT don't cook the fluid  (which translates into having or
installing a good transmission oil cooler).  A transmission fluid
temperature gauge would also be a good idea.

Assuming your automatic is adequate for the job, following 1 and 2 above
should provide long transmission life.

I am sure that eventually the transmission makers will agree on  (and design
for) a synthetic fluid.  However, I don't see the pressure for such a
development as great as that on engines or differentials.

Incidently, synthetic lubricants are often used in heavy duty piston air
compressors.  However, the synthetics lubricate so well that the air pump
manufactures advise against the use of the synthetic oil for the first 25 to
50 hours or so, because the synthetic will not allow the rings to "wear in".

Oliver Filippi