<VV> Towing Powerglide

[Smitty]

From: Joel McGregor <joel at joelsplace.com>
While it's true that the majority of the cooling comes from the converter 
spinning, the converter is also where the vast majority of the heat comes 
from so without the heat from the converter the transmission shouldn't even 
get warm.  I would be curious to see if it even gets noticeably warmer than 
ambient temperature.  Maybe someone that is towing will check?
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Smitty Says;  Joel I promise you that a PG will get hotter than a pistol 
while towing with the wheels on the ground.  How hot depends on duration and 
speed.  In my ignorance or willingness to gamble I have fried a couple of 
PGs.  I don't care if the heat comes from the converter or the pumps.  It is 
still there and can turn the fluid brown in a hundred miles.  While I am 
saying this I might add that leaving the car idle is not a foolproof way to 
protect the fluid.  The converter, which turns with the engine may be able 
to cool the fluid a little as it cycles the fluid from the tranny and back 
again, but to be truly effective it has to be spinning fast enough to create 
a centrifugal air pump, drawing in air and expelling it through the holes 
provided in the bellhousing.
Jet aircraft hydraulic fluid (which is very closely related to Dexron 3) 
have no converters, and do have large oil coolers and miles of tubing which 
gives off heat, to keep the temperature down.  Still the fluid gets very 
hot.  There are little pop up telltails throughout the aircraft which warn 
the mechanic that the fluid has reached 275 degrees and the fluid must be 
changed.