Please Help!!!
I have a 2002 with 130k and a factory cooler on it. I picked my truck up from getting new tires, tie rods, and an alignment. When driving home I noticed once that the transmission hesitated to shift then slammed into 4th gear when I was accelerating normally at about 35 miles an hour. 2 hours later, I undid the neg terminal for 15 mins to let the ECU reset. I drove the truck directly after. I didn't have any issues then after about 20 mins or around town driving it would hesitate and shift hard into 4the gear. Drove around for another 30 mins and it happened a couple more times, but it didn't happen every 3rd to 4th gear shift. Any idea what is going on here? Please help and ease my mind. Thanks!