Do you have the end on the pivot lever with the double bearing going into the box? Do you have the pivot levers slot parallel with the worm gear? From the FSM

(57) Install valve pivot lever (double bearing end first) (Fig. 24) into center race and spacer through
hole in steering housing so that slots in valve lever are
parallel to worm shaft in order to engage the anti rotation pin in center race.
Install valve pivot lever spring small end first.
Turn worm until the piston bottoms in both directions and observe the action
of the lever. It must be in the center of the hole and snap back to its center
position when the worm torque is relieved.