Where is Shift Solenoid located

On a 2005 Ford E350 6.0 Powerstroke Diesel, I am getting a code P0766 Shift Solenoid hello my name is Serge I just bought my 2005 Ford E350 Super Duty 6.0 Diesel Box Truck and was told that Transmission was rebuilt but was not given a receipt or know what was done to it and I started driving on a highway I started to have Shifting problems with in 40 miles of owning it, It was slipping in and out of gear with the RPM Gauge going up and down as it was going in and out of gear, there was no codes at that time, then I Drove for 650 miles and got a 3 codes all had to do with Transmission Range Sensor, I bought one and Installed it myself it was an internal Range Sensor, I had to pull off the Transmission Oil Pan to do it,

It was my first time, doing that but not first time of servicing my Cars, I am Not a mechanic but, I like to fix my own cars, So anyway after I removed the Oil Pan I did take pictures of inside, to my surprise it was very clean and shiny, I did notice right away the Transmission Range sensor and Solenoids 5 of them all Round, After Replacing the Transmission Range sensor the code cleared but the vehicle still slips in and put of gear, a new codes emerged P0336 Crankshaft Position sensor and PO766 for Shift Solenoid So I got one from a Parts store looks square and has electronic plug in with a mounting bracket that has 1 hole on each side on the part it self there is a number F8AZ-7G484AA on top and a number on bottom 2581, so I was hopping to get help finding where this part goes if I drop my oil pan where can I see it Please help me.

note while I am having shifting problems my speed gauge is going up and down, I know I am going 50 but the arrow goes ti 25 and then goes higher and lower, like it can't tell what speed I am going, I also replaced ABS sensor on deferential and fluid toped of I was missing 3 courts.

Note sometimes if I am not getting this problems it drives and shifts fine.

Note, I also noticed after pulling up to a stop sigh or a light and I have vehicle in Drive and foot son brake it feels like transmission is shifting and like it wants to go I even feel like it slightly makes my van go forward.

note Other then that The engine sounds good and and sometimes even drives good.

Question does e350 have a Transmission Module Like other cars if yes where can I find it and can It be reprogramed and if yes what is the best approach in any way.

Thanks so much for your help please