DECKMASTER PUMP   NEUTRAL   ADJUSTMENT   ( continued    from page 6) •7. If the transmission operates as shown by motor shaft rotation, reduce sped to idle.  Using a 3/16 inch  internal  hex  wrench,  slowly  turn  the  null adjustment screw clockwise or counterclockwise until   the   transmission does   not   operate.   Repeat   step   6   Note   that charge  pressure  should  drop  approximately  20 psi with forward or reverse stroking of the pump washplate due to the shifting of the shuttle valve in the motor manifold. •8. With   a   3/16-inch   internal   hex   wrench,   slowly turn  the  null  adjustment  screw  clockwise until charge pressure begins to decrease.  Then slowly turn the adjustment screw counterclockwise ,  observing  the  angle  of rotation,  until  charge  pressure  decreases  again (charge  pressure  will  rise  in  neutral  and  drop when going into stroke). ORDERING INFORMATION A  range  of  options  to  the  basic  HDC  allows  it  to  be custom   tailored   to   each   application.      The   control   is specified by filling in each slot of the order number, as is shown   in   Table   B,   with   the   appropriate   model   code. Other options are possible.  Consult Sundstrand Mobile Controls with further questions. TABLE B.  INFORMATION NECESSARY TO SPECIFY THE HYDRAULIC DISPLACEMENT CONTROL 1. DEVICE IDENTITY This   is   the   basic   HDC.      The   model   code   is MCV106A. 2 CONFIGURATION (including assembly kit) PRESURE WITH MODEL LIMITER OR ANNULAR CODE PRESSURE CONTROL OVERRIDE 5 NO* NO 8 NO YES 7 YES** NO 8 YES* YES *PRESSURE OVERRIDE ONLY **MODEL CODE 7 DEVICES MAY NOT BE USED ON SERIES   3X   PUMPS   IF   ORDERED   LESS   LINKAGE ASSEMBLY ("9" UNDER THE SERIES PARAMETER). •9. Turn  the  adjustment  screw  clockwise half the amount of the turn observed in step 8.  This should be the center of neutral. •10. Hold the adjustment screw and securely tighten the hex lock nut on the adjustment screw to 14- 18  foot-pounds.    Note  that  if  a  motor  is  used which does not have a manifold, neutral should be adjusted (steps 8.10) by observing the motor output shaft rotation without a load. •11. Stop the prime mover. •12. Run the system briefly to ensure that it operates proportionally on both sides of the null command.        Swashplate    movement    can    be verified by watching movement of the swashplate feedback shaft, shown in Figure 1. The Pressure Override and Pressure Limiter accomplish the    same    function-they    shift    the    pump    swashplate toward neutral when system pressure crosses a pre-set threshold.      They   thus   limit   system   pressure,   protect components  from  heat  generated  by  flow  across  relief valves    and    conserve    pump    horsepower.        Pressure override   is   available   only   for   Series   2X   pumps,   and pressure limiting is available only for Series 3X pumps. Pressure  limiting  and  annular  control  are  not  available together.    If  the  model  code  chosen  indicates  that  the pressure  override/pressure  limiting  function  is  desired (i.e.,   "yes"   is   chosen   in   the   second   column   of   the configuration parameter, above), only pressure   limiting will         be   provided   directly   by   Soundstrand   Mobile Controls   (pressure   limiting   is   accomplished      using   a different   porting   spool);   the   Pressure   Override   Valve must be obtained through Sundstrand Hydrotransmission.  See below. Stroke  controls  with  annular  control  have  a  groove  cut into the spool bore of the housing that allows for higher flow  from  the  control  ports  when  they  are  uncovered, increasing swashplate response. Kits  are  needed  in  order  to  install  the  HDC  onto  the pump.    Which  kit  is  shipped  with  the  HDC  depends  on which  pump  series  is  ordered.    Included  in  the  kit  are: retaining  rings,  swashplate  pin,  drag  link,  orifice,  hex screws, O-rings and gasket  In some cases not all of the above  are  necessary  for  installation  and  they  are  not included  with  the  kit.    Individual  drag  links  will  not  be supplied  by  Sundstrand.    Consult  Mobile  Controls  for replacement parts- ORDERING INFORMATION