Transmission does not upshift. Shifts from park to reverse to neutral to drive but does not upshift from 1st gear. 117000 miles on the odometer HELP!!!

Thanks for the quick response. I don't believe it is the output sensor. The speedo still works fine and I believe that the output sensor controls the speedo. Which sensor on the front of the tranny is the speed sensor? I know one of them should be the neutral safety switch but there are two other sensors there as well. Thanks for the quick response. I don't believe it is the output sensor. The speedo still works fine and I believe that the output sensor controls the speedo. Which sensor on the front of the tranny is the speed sensor? I know one of them should be the neutral safety switch but there are two other sensors there as well.

It actually has two speed sensors on the front of the trans and a Speed sensor on the rear for the speedo. The speed sensors that are on the front are halfway up on the trans. The two above the lip of the pan are the Neutral switch and the reverse light switch. The input shaft speed sensor is right above the solenoid assembly. The output shaft speed sensor is at about the same high but out but the drivers side wheel. The vehicle speed sensor, that runs the speedo, it in the housing that the passenger side cv shaft slides into. It actually has two speed sensors on the front of the trans and a Speed sensor on the rear for the speedo. The speed sensors that are on the front are halfway up on the trans. The two above the lip of the pan are the Neutral switch and the reverse light switch. The input shaft speed sensor is right above the solenoid assembly. The output shaft speed sensor is at about the same high but out but the drivers side wheel. The vehicle speed sensor, that runs the speedo, it in the housing that the passenger side cv shaft slides into.