Transmission Question.

Alright, so I've had my 63 amb***ador wagon sitting for a good 2 or 3 weeks now. I moved it today to get weldings done at a local hot rod shop. Guess what I found? The ****** is leaking, again, but when I crawled under it, it wasn't the pan, it's new anyway. Instead it was coming for a part that I have no idea what it is. Which is what I'm trying to figure out, what is it? It's a metal cylinder, a couple of inches long. it's right behind the ****** pan, but up, out of the way.

I looked in my technical book, and I didn't see anything like it, or at least not yet. I'm not very mechanical. Anyone know what it is?

Car is an automatic.

 

Not being familiar with a 63 Ambasador auto gearbox, I'll say this. If the round thing is held on with a clip and one bolt, it has an O ring on it to seal and will be an easy fix. It will be the vacuum modulator

 

found it, called a vacuum and solenoid control.

 

That was only used on the cast iron ramblers, hopefully it's just the small gasket where it screws into the case.