I don't believe I was making any waters muddy.... This NG encomapsses folks
from all walks of life... including thse that are driving old technology....
not because they want to but because that's what they can afford.
Additionally, I see no debate.... early overdrive transmissions had concerns
with the overdrive function. Since torque is reduced through the use of
overdrive, these components were often constructed of lighter material or
less substantial amounts of materials. Hunting between direct and overdrive
has killed many A4LDs and AOTs.
Your advice would lead those with these older units to believe that OD is OK
in urban use, quite possibly causing them financial burdens they can ill
Are automatics designed to shift up and down??? Of course..... Does a
certain amount of wear occur with each shift? Yes.... Will a "hunting"
condition increase this wear? Yes... The transmission is chock full of
sacrificial parts... if there is an action that someone can take to increase
the life span of these parts, it should be made known.
I have no idea where you are going with the "overdrive on the A4LD and AOD
are an integral part of the trans".... Of course this function is part and
parcel of the transmission assembly..... How could it be otherwise? Even
though this function is "integral" to the transmission, it does not follow
that the function should either be used or allowed to operate at all
times... especially when we deal with older technology.
Rather than offer a blanket "fugedaboudit" statement, these people deserve
to know that there have been historical concerns with OD function in urban
use. They are intelligent enough to form their own opinions as to whether
they want to allow OD function or not. If they decide to cancel OD, it is
their choice and, as I had stated. if we are to make an "error", our error
should save us money... not cost us money.
Now... getting back to your statement about the calibration of the engine
controls..... On both the A4LD and the AOT the only "engine control" I can
think of involved torque coverter lock. Overdrive function depended largely
on either a vacuum modulator (for engine load sense) or a throttle valve
cable (again for engine load sense). Where, in Gods name, does PCM
calibration enter the picture?
Remember, in this venue, the past is not so distant and decent advice for
one reader is terrible advice for another.