orrum
New Member
Ok I am new 2 diesel trucks. The truck is a 1991 3500 6.2l dually with a 4l80e tranny. It has run great and shifted perfect since I bought it, 1000 miles and suddenly it shifts hard from 1st to 2cd and has no overdrive and no passing gear. This happened after I noticed the cruise control cable was broken and the previous owner had duck taped it and I decided 2 cable tie it. Then I test drove it and had the shift problem. I have been checking threads plus I posted a thread on the 6.2 forum and they have helped a lot but suggested I try the trans forum. I have checked the grounds and found one hanging loose behind the passenger front fender, it belonged on the block so I attached it with a screw hose clamp to a exhaust bolt and got rid of the code 22 and test drove it and no help so I ran a ground from the fender to the alternator mount bolt and got rid of the code 22 and test drove it and no help. So I borrowed a test gauge and figured out the tps ground wire and 5 volt wire and the variable volt wire, I tested the throttle opening and got a nice even constant increase so I figure the tps is good. So I adjusted the tps slightly 4ward and did the paper clip thing and the code 22 was gone and then I messed up and started without taking the paper clip out, I snatched it out real quick and test drove it and it shifted hard and no overdrive so I pulled over and shut it off and restarted and drove off and it shifted perfect, I stopped and started again and did great, I even turned the motor off and restarted and it shifted great so I turned and headed 4 home and @ 55 mph I set the cruise control and it sorta hunched but then settled down and the cruise worked great so I pulled over and started out and the hard shift no overdrive was back! Next I checked and got code 12 and 22 as usual but could not get 22 to clear by unhooking battery and no voltage on tps wires. Gave up and went to house for ac and water. Then tackled it again and I must of not been useing the tester right cause I had proper working tps and I could reset the codes and eliminate the code 22. Went for test drive and it shifted perfect but when I stopped @ a stop sign and pulled out it was back to hard shift and no overdrive. So I put tools up and am hoping u here @ the trans forum can help me. Thanks and sorry the post is so long.