OK, I was not able to read that very good last night. It was very blurry, but I was able to see it better today. You are right I was referring to the picture you put up that has the Ford header on it that just explains the part numbers and all The listing at big listing at the bottom of it only showed the 4r100’s. I am not a Transmission guy, but if I am understanding the diagrams correctly, they only show an extension housing for a 2 Wheel Drive. With mine being a lariat four-wheel-drive does the transfer case take the place of the extension housing? And basically to find where the hole is at this plug goes. I have to remove the extension housing or transfer case and I should find the hole just below the main shaft. Correct?
and to be totally honest, the only problem with the transmission that I was having before I found this was putting it in reverse and it automatically grabbing and wanting to takeoff or stall the truck unless I tap the gas. And since I did that fluid change, I no longer have that problem reverse works perfectly along with everything else.

 

These questions are best answered by reviewing both of the diagrams showing the parts.

Remember that if you click on the photos, the photos will enlarge in another window at full resolution, where they might be easier to read.

But they must be read and studied in order to be understood.

As the diagrams show, and as the part number boxes explain, both the 4x2 and the 4x4 transmissions have extension housings.

Each type of extension housing is drawn, in each diagram.

The part numbers for the 4x2 and the 4x4 extension housings and transmission cases are given at the very top of the TSB diagram.

The extension housing for the 4x4 transmission is fitted between the transmission case and the transfer case.

 

Curious if you ended up putting the plug back or ran it without and if you've had any negative results? I recently found the same plug in my pan and now I'm torn if I should leave it out and run it or deal with taking everything off to get to where its supposed to be.

 

no, I did not tear anything else down. An old verbiage if it’s not broke, don’t fix it. Lol I’ve had no kind of adverse reactions or anything from not doing it.