Shifting between 2nd and 3rd engine revs like it in neutral. I have to put it in neutral then back in gear and it'll shift fine into gear. Also when it shifts into overdrive after 2 seconds of being in OD the RPM will rev way up like its not in gear. Once I put it in neutral then back into gear it'll shift fine and stay in OD. I just had a new computer put in it and this started a week after. I don't think that has any think to do with it. Is it pulling any codes for tranny? Please help.The fluid is full. I'm gonna change the filter and fluid and put some Lucas in it and see if that helps.someone told me that I should change my PSOM (gauge cluster). Which I need to anyway because oil press temp gauges and odometer doesn't work. I just didn't think that would have much to do with the tranny shifting.
To properly diagnosis a transmission problem you would need to go to a Ford dealer or certified transmission rebuilder. The mechanics have a scan tool to properly diagnosis the electrical part of the transmission. The scan tool can check for trouble codes and also check computer input data and output data related to shift solenoids voltages, resistance and shift sequence. The scan tool can check the computer that was installed to see if it is functioning properly.
They also have a pressure gauge to check transmission pressures during shift patterns and can use this information to determine if the problem is related to a mechanical issue inside the transmission.
There are a few related problems inside the transmission that are mentioned in service bulletins like replacement of accumulator pistons and steel rings which seal certain areas of the transmission to direct fluid to where it needs to be. If the seals are malfunctioning they can cause a pressure loss causing shifting problems.
Do not add Lucas oil to the transmission, additives are not recommended for shift improvement and could cause other issues.