Looking for experienced advice on what to do next, 1992 Dakota LE V8 longbed. When I bought it in 2000 3rd gear was out, had tranny rebuilt then and all was great until recent problem when suddenly truck did not have higher gear for highway cruising speed. Light on OD button is functional, button feels fine as ever. Searched forums and began trying to repair it. First changed fluid and filter, installed improved 3-4 shift accumulator spring, and adjusted bands following Haynes manual. (Original 3-4 shift accumulator spring was not broken or damaged). No change. Then installed new TPS at throttle body rear. This sent the truck into limp mode, threw all sorts of codes. Removed and reinstalled old TPS and all was well again. Next installed new Transmission Speed Sensor at transmission rear. No change to highway RPM. Next, dropped valve body, installed shift kit (Superior transmission parts A500 kit), cleaned and lightly polished valves, all while dong the main thing: replaced solenoid set with new one. After this, NO AUTOMATIC SHIFT AT ALL. I assumed I committed some catastrophic error, so dropped valve body again, disassembled, checking everything, slowly reassembled using diagram, high confidence there are no obvious screw ups visible. Re installed, no change, no automatic shift! Re set and adjusted the TV cable at throttle body, no binding at tranny, looks good. Still no change. Pulled codes 37 and 45. Disconnected and cleaned many electrical contacts, and fixed one vacuum leak up top. Replaced neutral safety switch. No change. No automatic shift. Truck has park, neutral, reverse, low and second gear manual shift, but no automatic shifts at all. Driving in D truck appears to be in 2nd , because as I downshift from D to 2 no change, but from 2 to 1 truck shifts down, rpms up, with engine braking as expected. SO based on the codes would you at this point assume the new solenoid kit was DOA and reinstall the old solenoids? Everyone says this is super rare. At least this would help eliminate the issue since the old solenoid set shifted in automatic. Would you drop the pan or keep chasing code 37 & 45 electrical issues outside? These codes seem real general and the whole thing seems surreal.
band was maladjusted a little, corrected this, no change. Suspect servo now. Grrr. Still using process of 'limination.
Dropped it and swapped in new solenoid kit. No change. Using a Dodge Transmission diagnosis chart, I see front servo/kickdown band could be the problem, and I did adjust this! Will double check this; maybe it's way too loose or something!
I'd drop the pan