Help, I'm rebuilding a 76 Thunderbird power steering box basicly the same innards, piston & rack even used on Broncos & F-150. Its a Thompson & my 74 Motors manual calls it a torque arm box. The picture in the 74 manual shows a check ball at the bottom maybe thru the cast in, drilled passage port from the top. I was extremly careful disasemble, even had it in a pan to catch the oil. Did they not use this ball later on? Where does it exactly go? Thanks to those who reply