So I just purchased this truck. It had engine DTC codes. When I pulled the codes one was the p0720 output speed sensor. So I figured it was an easy replace the sensor and all fixed. I was wrong. The truck shifted pretty much normal and no slipping, maybe a little lag going from first to second gear. So I crawled under the truck to replace the sensor and I noticed it was disconnected. So i cleaned it up and reconnected it. I cleared the DTC codes and went for a drive. First gear was solid but it didn't want to shift till I let off then it went into second gear. Then the transmission was slipping really bad. I got it home and changed out the sensor figuring it was bad. Same results. So I disconnect the sensor and it drove pretty much normal again.
I am pretty concerned as i just bought this truck and didn't think the tranny was bad.
I hope someone can shed some light on this. Oh the fluid level is good clean and no smell.
Thanks for your help

 

Your next issue will be jumping back and forth between second and third gear....you are looking at a rebuild I'm sorry to say. We have all been there.

 

That's a real bummer. I thought the tyranny was good as it shifted pretty good and no slipping (while that output speed sensor was disconnected). I guess I will start shopping for a rebuild shop around here. Thanks for the reply