Just purchased an 89'

[Mokerz]

Just purchased an 89' not too long ago. The transmission will not shift on it's own. You must manually put it in each gear up and down. The previous owner had the transmission rebuilt 2 years ago. Had the problem when I bought the truck and I have not driven it more than 10 miles yet. I have a overdrive transmission out of a 93 to put in it if I keep it, however somebody just offered me $3500 for the truck as is so long as the transmission shifts correctly. So, does anyone have a clue what could cause this. Previous owner said he tried adjusting the linkage, I am not sure what his mechanical ability is. I am shop foreman for a medium sized trucking company and have a lot of mechanical experience, but have very limited experience with the 727 torqueflite transmission. Any help would be appreciated. Thanks

 

[mysteryman]

It sounds like they took the valve body apart and got some of the valves and springs put back incorrectly... I can't explain the correct

way to assemble it. But I could put it back right if it were on the bench in front of me