Sounds as if the linkage is screwed up. Is the replacement new? or used? I'm not familiar with FMX, but I know from experience that a C4 is different for a column shift and a floor shift. Same pieces, but the shaft your cable attaches to has a piece on the inside of the tranny that engages the valve body. The piece is held on with a nut. Have to remove pan and valve body to get to it. The shaft that your cable attaches to has a metal piece to accept the cable. This piece can be pointing up or down, depending on the application (column vs. floor). If you have a column shift, and the tranny is set up for a floor shift, your pattern will be reversed, and vice versa. The floor shift cable attaches from the back, and the column shift cable attaches from the front. I'm referring to a C4, but an FMX is probably similar.