My 94 Silverado has a rebuilt 4l60E transmission with only 2000 miles on it that shifts fine from 1st to 2nd, but 3rd gear eludes me. It occasionally shifts into 3rd and 4th but it is very inconsistent. I
am not having any speedometer issues. I have changed the wiring harness from brainpower to back of motor, reset the TCM as well as the brainbox. I have ālso cahnged both shift solenoids and changed the fluid and filter while changing them. There were no codes in the truck before I did reset them. I drove the truck foe about 10 miles and it still would not change into 3rd gear. It will not change if I manually shift inever has manually shifted since this shifted into 3rd gear at all now. There were no codes when I got back home and checked them. My speedometer is not acting erratically nor is my ram spiking. I have checked the grounds and they appear to be fine. I am stumped. I dont know which way to go from this point.