Superduty transmission fluid cooler

[A Fritz]

I have what is referred to as a "superduty transmission cooler" in line with the two standard factory fluid cooler/warmer's on my 92 w250 4x4 ctd. I remember discussion on our site regarding this thermostatically controlled fan/coil in the past. Does anybody have any info on what temperature the thermostatic switch operates? This fan/coil is located under the trucks box inside the frame rail behind the drivers seat. If somebody has this aux cooler on their rig, and had this switch fail on it, would appreciate any info on where to get a replacement.





A Fritz

 

[PToombs]

Not sure where the original switch is located, but I know Summit has some inline ones for different diameter lines. I think "on" is about 180*. New link is in post below.

 

[A Fritz]

The switch is made of brass/1/2'npt threads that screws directly into the radiator coil/cooler of which it is part of and directly is immersed in the automatic transmission fluid that passes through the radiator coil/cooler. Two wires exit the switch, and directly turn on a fan that is bolted to one side of the radiator coil/cooler. Electrical wiring is provided (b+ and ground) in a wiring harness coming from the front of the truck (this wiring appears to be factory)and has a watertight plug connection on it to plug into the thermostatic switches plug to match.



A Fritz

 

[dodgenstein]

I knew I had posted this sometime back. Took a little while to dig it up:



https://www.turbodieselregister.com...93/74473-aux-trans-cooler-thermal-switch.html



Hope this helps!

 

[A Fritz]

Thanks Dodgenstein for your help. I will use the info provided from the archive that you dug up. First I am going to check around at some of our local parts suppliers, as I think I might be able to hopefully do a little better than the $120 price. Still if someone has a temperature value that this temp. control switch operates at I am looking for some input. I will need temp. values for the search. I believe that the switch contact should close to operate the fan@ 180F, and transition open around 170F to turn the fan off.



A Fritz

 

[PToombs]

I didn't realize the link didn't work. Derale Cooling Products 15721 - Derale Cooling Products In-Line Fan Thermostats - Overview - SummitRacing.com

If you get this 1/2" one from Summit it fits those specs. You can adapt from the JIC flare to NPT easy also. $25 is way better than $120!

 

[Flexiheep]

Been using one for a year.

I didn't realize the link didn't work. Derale Cooling Products 15721 - Derale Cooling Products In-Line Fan Thermostats - Overview - SummitRacing.com

If you get this 1/2" one from Summit it fits those specs. You can adapt from the JIC flare to NPT easy also. $25 is way better than $120!

I am using this piece to run the relay that turns the fans for my 2 Derale coolers on and off for my transmission coolers. No problems yet, no leaks or anything and it turns on and off when needed. For simplicity you can run it inline without a relay, it is rated for 15 or 20 amps.