So, you’ve got your Turbo-Hydramatic 400 transmission installed, and the shifter adjusted spot-on perfectly.

Now, ever wonder what’s actually going on in your transmission when you shift?

Well, the transmission aces over at ATI Performance Products will show you.

(Image/The ATI Performance Products YouTube Channel)

The ATI team grabbed a TH400, flipped it over, tossed it on a workbench, took off the pan, and installed a shifter cable.

Then, they work through the gear shifting mechanism, so you can see firsthand how the detents and lever work together to get your vehicle into gear (and keep it there).

It’s one of those “ahhh, neat” sort of videos that’ll give you some fun insight into what’s actually going on in your transmission when you grab your shifter—and who knows, it might even help you diagnose some hard-shifting or gear crunching issues too.