TM 10-3930-653-14&P (5)   Lightly tighten the valve body with two  bottom  cover fitting  bolts.    Raise  the  caulked  part  of  the  lock  nut. Holding   the   steering   shaft,   remove   the   lock   nut. Fig. 4-431. (6)   Remove the two bolts which were hand tightened in the  preceding  step,  and  remove  the  control  valve. Care should be taken to prevent the reaction  spring seat,    reaction    spring    and    reaction    piston    from popping out. Fig. 4-432. (7)   Remove  the  top  cover  fitting  bolts  and  remove  the top cover. Fig. 4-433. (8)   Remove the worm assembly from the gear box. The worm    assembly    must    be    kept    horizontal.    Never disassemble it. Fig. 4-434. 4-215