What is the flow of transmission fluid?

Pan to torque converter to tranny to transmission cooler (if equipped) to pan?

I ask because if you were draining fluid from the cooler return line and adding cooler to the pan would it keep everything lubricated?

 

Sounds like you want to do a transmission flush of some sort. You can do it kinda this way if your transmission doesn't have a thermostatic valve.

The safe way is to drain the pan..refill the pan...have the return line go to a container so you know exactly how much fluid comes out and stop engine...refill pan with that exact amount of fluid...start engine and repeat procedure.

Can't do that with the 10R80 in my 18 truck since it has a thermostatic valve...yours may be the same in a 16.

 

The 6 speed does seem to have thermostatic valve, but based on the videos I've watched it seems to be in the return line at the transmission. That means the pump pressurizes the cooler and the lines even with the valve closed. Seems like people pull the lines apart in front of the engine to drain the ATF with the pump pushing the fluid out. No idea if this is good practice or if dirty fluid is being recirculated from the torque converter to pan during the "flush". They either seem to run out 4 qts, stop the engine and refill the pan or pump new into the pan at the same rate as it pumping out.

 

Personally, that method seems like a bad idea. You are only saving a few minutes instead of stopping the engine and refilling the pan.

Or you can do what I do now...just change the fluid in the pan more often. I change mine every 30K.

 

^^This. Dorman makes a replacement pan with drain plug for like $50. Don't overthink it.

15-17 doesn't have the thermostatic valve that 11-14 had and 11-17 mustangs have. They use the valvebody full flow plug instead and move the valve to the front of the truck with the heat exchanger and use engine coolant temp to heat the trans fluid.

 

sounds like the start stop method is the best way to make sure you replace the right amount of fluid.

but is the transmission cooler the last stop before it goes back into the pan??

And how much does the pan hold?

 

Do a drain and then fill it up...you will find out then. That's what I did and wrote it down so I have it for the future. Mine is a 10R80 and will be different than your transmission

 

Ok, so get the doorman pan with plug and the fluid needed get the engine and trans warmed up.. Is there a safe place to puncture the factory pan? Stab it, replace filter and install doorman pan. Crazy? Yeah, probably.

 

If you're going to poke a hole in the original i'd pick the lowest point, the dip in the middle, to do it. Worst case the filter is right above it and will keep you from sending a point into the valvebody