[A/S] transmission temperatures

[jon fitz <fitzjo1@xxxxxxxxx>]

We just made our first trip with our "new" 68
Overlander.  This was quite an event for us.  I'm very
excited and thought I would blabber to a receptive
audience.  It seems that most folks at work don't
understand this obsession of ours.  

Having tent and car camped for many years (before
children) I am still marvelling at what would pass for
a european hotel suite.  I was also pleased by the
logic of the layout in actual use.  

The Airstream really did tow nicely.  I did the first
part of the trip without even putting on the anti-sway
device.  When I finally put it on, it did make things
feel more stable.  But, compared to the horror stories
of SOB owning friends, the Friday afternoon truck
traffic on I-26 was pretty anti-clamactic.

I noticed that in my van (E-250 with 5.8L V8) you can
tow at two speeds.  If you are in third, you pretty
well limit yourself to 60 (I don't like to rev the
engine too much).  If you tow in OD (as instructed by
the manual) you really must go fast so that you keep
the RPMs in the higher torque range (2000+).  I must
say I was pretty excited to discover that I really can
tow the trailer at normal highway speeds (normal at
least for a person who normally doesn't speed). 

But, this brings me to my question.  Lots of folks say
not to tow in OD. I think this is because it can
overheat the transmission.  But, strangely enough,
driving an average of 65 or 70 in OD doesn't seem to
make the transmission any hotter than driving 55 or 60
in 3rd!  In fact, the gage sometime dropped a little
when going downhill in OD.

What is a normal temperature for a transmission while
towing? My gage showed about 180-190 degrees F.  This
is much warmer than when not towing.  But, the
temperature isn't reduced at all when towing in third.
Is mine fine in either gear, or simply too hot all the
time?  

Answers appreciated.  

Jon in SC
68 Overlander