TM 5-3895-382-24 Swashplate Neutral Adjustment Procedure (9XL229-Up, 3WZ158-Up, 2JM579-Up, 4JZ122-Up, 3TM706- Up, 5BZ119-Up, 6EN127-Up, 2TN118-Up, 1ZN121-Up, 1FS1- Up, 1XZ1-Up) Tools Needed 6V-7830 Tetra Gauges 1 Make reference to WARNING on first page of Troubleshooting. NOTE: Tests should be performed on tires or loose dirt. Tires    are    recommended.        Never    operate    the vibratory     system     when     the     machine     is     on concrete. NOTE: Make  sure  the  parking  brake  is  applied,  and  the propel control lever is in neutral. Flushing Manifold. (1) Test port for vibratory high amplitude) pressure.  (2) Test port for vibratory (low amplitude) pressure.  (3) Servo port. Vibratory Pump. (4) Servo port.  (5) Pump neutral adjustment. 1. Connect two 60 000 kPa (8700 psi) pressure gauges to test ports (1) and (2). 2. Remove  plugs  from  servo  ports  (3)  and  (4).    Install  a 3445  kPa  (500  psi)  minimum  pressure  hose  between servo port (3) and servo port (4).  This will cross port the servo and remove the effects of any control pressure on the servo piston. 3. Start  and  slowly  accelerate  the  engine  to  full  throttle. Operate   the   vibratory   system   in   both   high   and   low amplitudes  several  times  and  then  stop  the  vibratory system. 4. With the servo cross-port line installed, note the system pressure  gauge  readings  with  engine  running  at  low idle.      The   difference   in   the   system   pressure   gauge readings is the offset pressure. NOTE: To achieve finer gauge resolution, lower pressure gauges  will  be  required.    60  000  kPa  (8700  psi) pressure   gauges   are   used   at   the   beginning   to prevent gauge damage. 5. If   the   offset   pressure   is   not   zero,   loosen   the   pump neutral  adjustment  locknut  with  a  17  mm  hex  wrench. Turn  the  pump  neutral  adjustment  screw  (5)  with  a  7 mm   hex   wrench   until   the   system   pressure   gauge readings are equal. 6. Turn the pump neutral adjustment screw (5) clockwise until one of the gauges registers an increase in system pressure.      Note   the   position   of   the   pump   neutral adjustment screw (5). 7. Turn the pump neutral adjustment screw (5) counterclockwise   until   the   other   gauge   registers   an increase in system pressure.  Note the position of the pump neutral adjustment screw (5). 8. Turn   the   pump   neutral   adjustment   screw   (5)   to   a position  halfway  between  the  positions  noted  above. The   system   pressure   gauges   should   indicate   equal pressures. 9. Once the swashplate neutral has been found, hold the servo  adjustment  screw  from  turning  and  torque  the pump neutral adjustment locknut to 28 to 51 Nm (21 to 37 lb-ft). 10. Stop  the  engine.    Remove  the  pressure  gauges  and servo  cross  port  line.    Reinstall  the  plugs  in  the  servo pods (3) and (4). 13-34