Power Steering Box rebuild

A couple of months ago I bought a 1967 Valiant 225 slant 6 and power steering, disc brakes in front, 4-1/2 inch bolt pattern on all four and 2 bbl carter carb with intake.

I just replaced the whole front end with 75 parts and rebuilt the power steering box, which is date coded 3061. (As I understand 306th day if 1971.) When we tried to adjust the neutral setting on the top of the box we cannot get it to center. It is very sensitive. Does anyone have any suggestions?