Re: Landry's Trans cooler

[jlandry@domain.elided (John A. Landry)]

In a brilliant stroke of genius, Mark A Pepe <mpepe@domain.elided> blurted
out:

>	I installed a similar size cooler in the exact same spot
>and have noticed the same temprature increase. I only have the stock guage
>but it used to read about 1/4 to 1/3 in normal conditions except for in
>traffic here in the summer when it's over 100. Now it reads about 1/2 when
>driven for more than 20 minutes unless it's below 80 outside and I'm
>moving along (creating more airflow) It seems as if the addition of the
>new thermastat (Robert Shaw) has made it average a higher temp too but the
>guage never goes above 3/4 and it used to in heavy traffic and  trail
>driving in the heat. I almost want to rig a removable electric fan that I
>can mount on the front of the grill and operate with a switch in the cab
>when I'm poking along on a trail and need more air flow. 

Yesterday and this morning I commuted in my Traveler with the flow to the
coolant filter shut off.  With the transmission oil cooler in place and a
180 degree "Robertshaw style" thermostat (it's actually an older Stant I
had on hand), the coolant stayed pretty much pegged at 180 degrees exactly
under freeway cruise conditions.  Before the transmission oil cooler was in
place, with the coolant filter also shut off, the coolant temperature would
stay closer to 175 degrees at freeway cruise.  So the having the
transmission cooler in front of the radiator does make a difference and
increase the coolant temperature somewhat.  I don't know if this is related
to the transmission cooler or not, but when I slow down on the freeway...
like when traffic becomes slightly congested, the engine temperature drops
down to about 175 degrees.

When I pulled my trailer up a steep hill on the freeway (not overly steep
on a freeway of course) this past weekend, The engine temperature reached a
maximum of 195 degrees and stopped there.  This is with the old style
thermostat (like the Robertshaw) in place, no transmission cooler yet, and
the flow to my coolant filter turned on.  In the past, with a typical newer
style thermostat, the coolant temperature had reached over 210 degrees.
But it's not really a fair comparison, as the last time I pulled the
trailer up that hill it was still Summer and warmer.  But on the surface of
this unscientific test, it appears that the older IH style thermostat works
better than the newer styles Stant makes.  This is presumed to be because
of the way the older style thermostat is designed to actually block and
shut off the bypass port when fully open.  I'm of the opinion that at lower
engine loads the difference between the older and newer style thermostats
doesn't amount to much, but at high heat loads, the older style performs
significantly better... so much so that it's worth the extra trouble and
expense to buy a Robertshaw thermostat via mailorder from Jegs or Summit.
I recall they cost about $8.50 each from Summit (www.summitracing.com).

When I arrived at work this morning, I felt the transmission oil cooler and
it was quite hot.  I also grabbed one of the lines leading from the oil
cooler and it was *very* hot... much like a warmed up radiator feels... too
hot to touch for long.  So it's obvious the transmission fluid gets pretty
darn hot and the oil cooler sends quite a bit of heat into the front of the
radiator.  I'm sure cooling the transmission fluid like this goes a long
way towards extending the life of the transmission.  Ideally though, it
would be nice to mount the transmission oil cooler in such a way as to have
air pass through it and not the radiator, but that would be difficult to
impossible depending how much body lift a truck has.  It was certainly
simple to just mount it to the front of the radiator.  I was able to
install it in about an hour.

Regards,

John L.
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