I am having a problem with my light truck.
Why won’t my automatic transmission engage?
I cannot even disengage from park.
This sounds like problem with the transmission’s linkage.
There may a connector that fell off, or out of position and fully or partially disconnected the shift control linkage from the actual transmission shift arm.
The connector’s or clip’s movement may have caused the linkage to become jammed at an obtuse angle, thereby preventing it from moving the transmission’s shift arm.