Truck not shifting at all

Good morning,

I attached a picture of the external case. At the back on the drivers side, there is a cover that has the governor. That controls the shift points. It is a very common failure for not shifting.

https://www.2carpros.com/articles/automatic-transmission-problems

Remove the cover and pull out the governor and see if the plastic gear on the end is damaged.

Do you mean it will not shift down into the lower gears from the shifter?

Roy

When driving down the road it will not shift at all. I replaced the shift solenoids, but still no shifting. I noticed i cannot shift into my 2 lower gears manually from the shift handle. I did notice the cab seems to start dropping in back. could this be affecting it?

I read all that. I gave you what you need to check.

No, the O2 will not cause this issue.

Roy