TM 10-3930-669-34 3-3.  ENGINE/TRANSMISSION ASSEMBLY REPLACEMENT (CONT). NOTE Preload   is   when   the   plunger   of   the dial gauge contacts the internal plunger of the pressure screw. (11) Install  the  dial  gauge  in  the  pressure  screw  of the  adjusting  device  until  the  dial  gauge  pointer  moves. Tighten the compression nut. b.  TDC Adjustment. (1) Using retainer, turn pulley (7) to the right until dial gauge needle begins to move. (2) Using retainer, continue turning pulley (7) slowly until dial gauge pointer stops moving in one direction and starts to move in the opposite direction. 3-12