leaking transmission fluid from throttle on side of transmission.

Where the throttle bar connects to the transmission there is fluid leaking out. I am assuming its a bad gasket but can anyone tell me the name of the gasket and tell me how I would change it? I cant figure it out. I tried looking in the chilton guide but couldnt find anything. It's leaking from where the red arrow is pointing. Heres a picture of what im talking about:

 

The rubber "O" ring on shaft is leaking... Will require removal of pan, valve body and linkage from inside the transmission...

 

there is a seal just above the arrow...it's called the...shifter shaft seal...

 

Thank you!

 

I have replaced both the seal and the o-ring and it made no difference, still leaks.

Found this common issue in our C4 transmissions. One day I may pull mine apart and see if this is what is wrong with mine.

http://www.allfordmustangs.com/foru...shaft-throttle-valve-shaft-leak-solution.html

 

if it is...I wonder why it took 40 years to grow...too long...

 

It didn't take 40 years. Mine has always had a puddle of fluid under it.

I just figured all C4s leaked like that.

After swapping the seals a couple of times, and still leaking, I looked around on the internet and came across this fix a couple of times.