I have a 2005 5.4L with the factory super cooling transmission fluid cooler. The transmission line comes from the radiator to the cooler and then out the cooler back to the transmission.

I want to convert the lines in and out of the cooler to allow for the installation of a B&M cooler and need to know the thread information.

I cannot seem to find any information about the size, thread, pitch, etc. of what these fittings are and images are attached below. It takes about a 7/8" wrench to remove, so I'm thinking that these are some sort of 5/8" thread size ... though I suppose they could be a metric, as well. But, I cannot for the life of me find anything. All of my searches for the transmission line fittings just point me to the ones that go in and out of the radiator. Ugh.

They aren't tapered or flared. Just straight threads with an o-ring (as you can see in the attached).

I'm looking for something like this for the conversion:


Does anyone have any information about what these threads are?

Thanks.

 

I keep a set of good stainless steel nuts for measuring thread pitches and sizes.

Works great for finding the right size of fittings and bolts, etc.

 

Other than ManualF150's helpful "figure it out yourself" post, I assume nobody else can answer my actual question about the size of these fittings/threads?

Thanks.

 

It will be either 1/2"-20 threads or 5/8"-18 threads.

 

For those of you scoring along at home, those threads are 3/4"-16 threads. They are fine SAE or UNF threads (same thing, different sources will use different terms for the same thread)… no taper, no flare, not NPT or any other tapered pipe thread.

Now the trick is to figure out some way to get a 3/4"-16 male converted to a 3/8" ID hose … and a 3/4"-16 female to a 3/8" ID hose. Ugh.

I think this should work: 3/4"-16 UNF to 3/8" NPT and then 3/8" NPT to 3/8" ID hose barb:

 

Went with the fittings shown above, with the exception that I went with a 90-deg bend on the NPT fitting coming out of the factory cooler. So far, so good. Short 20 minute drive and no leaks ...

 

Do you have the part number for the fittings you used? I'm looking into doing this exact same mod on my 2007 f150 to keep temps down when hitting the trails. What cooler did you go with and do you happen to know how much your trans temp dropped with this mod? Thanks!

David

 

Look at post #5.