I hear its a good idea to put a cooler for e40d.

I am considering it since i tow with it. But do people mean the factory rad cooler or an independent auxillary cooler? and in series or replace?

Recommendations of brand/any pre-made bracket/hose assemblies?

 

AuroraGirl,
All auto transmissions will benefit from adding an auxiliary cooler, especially if you tow with it. In the south, Run the biggest stacked plate cooler that will fit in the space in front of your radiator. Stacked plates are more efficient than tube & fin coolers.

In the South, I would run this stand alone cooler by itself and completely bypass the radiator cooler. It was 101* here in Dallas, TX today and it rarely gets cold for very long here. In your area where it gets & stays cold in the winter I would plumb the auxiliary cooler first and then run it into the radiator cooler.This will keep your transmission fluid at a steady temp in the winter.

Adding a trans cooler is an easy, cheap mod. You'll be glad that you did it.

 

any brands? any that have premade brackets?

 

Pick a brand that's been around and has good standing in the industry for decent quality. Read the reviews. They may include some type of bracket but you will probably have to modify or completely make your own.

The JY is a good source for a cheap cooler. Lots of factory or aftermarket towing package equipped trucks out there. More choices in the newer trucks. If you go this route thoroughly clean the inside before installing in your truck.