Chrysler Repair: transmission problem with D-150 van, chrysler drb, drb ii

Question
I have a 1992 dodge ram (d-150} with a 318 and a 3 speed with overdrive auto transmission when it is cold it is very hard shifting. after it warms up it seems to be fine  I don't know if there is a sensor problem or what but sometimes the speedometor does not seem to read when i'm having the shifting trouble. any help would be most welcome. thank you
                        vince

Answer
Hi Vince,
As stated in my claim to be an "expert", I know very little about the truck/full size van models. If you have the electronic transaxle, which the 'overdrive' description implies, and because you relate this to the speedometer not working when the problem occurs, it is my suggestion that you check to see if the output speed sensor of the trans has gotten flakey. That is the source for the speedo signal and it also is key to the electronic controller's shifting behavior. The sensor is located to the rear of the vertical shift control rod on the right side of the unit, about midline in height. There is a fault code for its failure which can be readout with a diagnotic readout box for OBD-I systems like the Chrysler DRB II. Simple readers however will not properly access the transmission controller so you will want to find a dealer or shop with the DRB II reader and have them readout the trans controller memory via the blue plug that is probably located under the dash (the one in the engine compartment only reads the engine controller) as it is set up in the autos of the early '90's. The code for a flakey output speed sensor is 57. On the otherhand, the cost of the sensor may not be too much greater than the labor charge for doing a readout, so consider the option of just replacing it. Let me know, please, if you learn something interesting to share or have further questions.
Roland