Need help, let me go through this nightmare. Started with intermittently shifting 3-4. It wod work in the morning and get worse as day went on. Codes for low voltage 3-4 shift solenoid p0700 and p0976. Checked fuses all were fine. Decided to replace shift solenoids same problem. Upon further research decided to have harness to transmission checked by auto electric shop. Everything appeared fine. They did suggest replacing internal harness due to poor connection. I am fed up transmission shop feels 3-4 clutch pack is bad. I am done and have the transmission rebuilt. Works for a day then the problem returns. Take it back to the shop they open it back up but find nothing wrong and tell me they think the TCM may be bad. Dealer needed here so I take it to the dealer have TCM replaced. They call to let me know it did not fix the problem. There suggestion Valve body issue. I pay to have the valve body inspected and cleaned. They find residue and possible sticking valve but upon reassembly the problem persists. I must mention in doing research I also replaced ignition switch, lock key and key as I was having trouble with them anyway. I also replaced throttle position sensor for a cheap hail marry. All for nothing. I am taking suggestions, at this point I could have placed new tranny in the truck.