Date:         Sat, 24 Apr 2010 16:09:07 -0700
Reply-To:     John Bange <jbange@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         John Bange <jbange@GMAIL.COM>
Subject:      Re: Question about the fluid cooler on the auto tranny
In-Reply-To:  <00bb01cae33d$a39917f0$eacb47d0$@com>
Content-Type: text/plain; charset=ISO-8859-1

On Fri, Apr 23, 2010 at 4:35 PM, Robert Fisher <garciasghostvw@gmail.com>wrote:

> I thought perhaps it isn't there to 'cool' the fluid so much as it's
> there to bring the fluid up to operating temps and keep it there (and maybe
> cool it if it starts running hotter).
>

I'd heard the same thing before, that the transmission heat exchanger is
like the oil heat exchanger, meant to keep everything at a uniform
temperature and get it there as soon as possible.... but then I looked at
how the transmission cooler plumbing is arranged. The return line off the
cooler is a branch off the return line from the radiator. That line only
flows when the thermostat is open. That being the case, your transmission
heat exchanger only starts to exchange heat when the thermostat hits 87degC.
When I put in my rebuilt, I plumber the transmission cooler with the lines
that used to run to the rear heater (which I removed) because the manual
radiator return hose (now NLA?) was much cheaper than the automatic
wye-shaped franken-hose. I notice no ill effects. If I were to do it now,
I'd probably install a SmallCar transmission cooler, just to decouple it
from the cooling system.

--
John Bange