Recommendation For Transmission Cooling on 1999 Ford F-250 Super Duty With 6.8 Engine

Question:

I have a 1999 SDF250 with 6.8 engine and all trailer tow options. I have a transmission temp guage, the fluid temp raises when in stop and go traffic or driving slow in traffic. I have wondered about adding a cooling fan to the existing cooler for slow traffic. I have not looked at the pickup as of yet to see what type of trans cooler it has, what ever it is was factory. Can you suggest my options? Will adding a fan to factory work, or should I add an after market cooler and or both.

asked by: Gary G

Expert Reply:

I would recommend to add an aftermarket transmission cooler to your 1999 Ford F-250 Super Duty to prevent any damage to your transmission. The ideal operating temperature range of your transmission fluid should be 160 to 200 degrees. Adding the cooler will not bypass the existing factory cooler which is located inside the radiator. Adding a cooler provides supplemental cooling to the your factory cooler.

Transmission coolers are universal fit items. What you will need to do is find out how much room you have to work with in front of your radiator and find a transmission cooler that will fit your application. Choosing the largest available cooler like Derale Series 8000 Transmission Cooler Kit, part # D13504 is a good choice, because you cannot over-cool a transmission.

This particular cooler measures 12 inches tall, by 11 inches wide and is 7/8 of an inch thick. Check your truck and make sure you have enough space in front of your radiator and if you do then this cooler would work for you.

When installing a transmission cooler like Derale Transmission Cooler, # D13504, to your factory cooler, the path of the fluid needs to be from the transmission to factory cooler, then to Derale cooler, then back to the transmission. See attached photo that will show how the aftermarket cooler is installed on your vehicle.

When you run the aftermarket transmission cooler in-line after the original transmission cooler you will need a Derale Radiator Adapter Fitting, part # D13025. This adapter will allow you to connect the aftermarket cooler to the factory coolers output fitting to allow you to run the coolant line from it without having to cut or flare the original fitting on the factory cooler.

I am including links to a couple of FAQ pages on transmission coolers.