f250 tran shifting problem

my 1990 f250HD 7.3L diesel will not shift properly. the speedo drops off and the tranny goes in between gears.i have replaced all speed sensors, tps, and all temp sensors.it all starts to pour smoke out the back when speedo is not working.

If you have the digital speedometer/odometer, there is a control module for that. The PSOM (programmable speedometer odometer module), gets info from several sensors, and sends info to the PCM. Together, they control the shift points. If the PSOM is faulty, or losing power, it will cause erattic , harsh shifts. Check your fuses, if its an intermittent problem, could be a bad ground/connection for the module, or defective module. Dont quite understand the comment on the smoke, can you give more details? Good luck.
Later
Ed

Hi, RE, Your F250 trans shifting problems, Being a retired ford trans tech, and not a real wizard with diesels, I can give ONE basic point to start from, NO automatic trans, I don't care what kind it is, will operate normally without engine horsepower at it's norm. I know enough about diesels to know that with your black smoke emission, you have a rich intermittent fuel problem, thereby your loss of horsepower and eratic shifts, All I can say is start with the engine and I believe you will solve the trans problem. ....GOOD LUCK..Clay..