I bought the truck and after about 4 seconds from leaving it got stuck in second and nothing else worked, I repinned the Tcm, replaced it too, now I have all forward gears but when I put it in reverse it goes for about 5 seconds with a loud whining noise unsure of where from. I checked the fluid and it was perfect, I replaced every solenoid, internal wiring harness, the external speed sensor on the transfer case, checked all the wiring externally, replaced the neutral safety switch with the updated tan style, took it to a transmission shop and they said everything inside was perfect so I’m just absolutely lost at this point anyone have any ideas? Codes are p1720 and p0700

 

how many miles on it?
sounds like a failed pump