Auto transmission temperature is definitely effected by outside temperature
and load. It also is effected by the engine thermostat. Those temps are not
cause for alarm but they are showing a loss of thermal control. The setup is
kind of a questionable design. The cooler coolant supply is basically in
parallel with the radiator. The goal is to increase cooling capacity with
engine load. The down side is the coolant going to the cooler is at its
hottest temperature coming out of the engine. So if the engine the is
running at 190 the cooler does nothing until the ATF is over that.  The bulk
of the ATF cooling really comes from those fins on the torque converter. To
really get the ATF under control an external cooler can be a good idea. Same
for engine oil cooling.

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Robert Clemmer
Sent: Sunday, June 26, 2016 11:06 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Auto transmission cooler??

Does anyone know if auto transmission coolers have known go get plugged?
Maybe coincidence, but it seems that after I changed my front heater core
that the transmission runs hotter than it did before.  At highway speed it
had run at 200 or less unless stuck in traffic in hot weather after a
highway run.  Now it easily will move up to 220 -230.  This is a 91 wbx with
312,000 miles.  Transmission was rebuilt around 210,000 miles.

Thanks for your thought and comments.

BobC