TM 10-3930-653-14&P MAINTENANCE AND CHECKING CAUTION Pay    special    attention    to    the    following    items    during operation,  or  else  the  service  life  of  the  Tor-Co-Matic^®, transmission will be shortened: 1. Changing   the   transmission   direction   while   the truck  Is  still  moving  must  not  be  substituted  for braking. Reason: It will hasten deterioration of the torque converter oil 2. Inching   operation   for   a   long   time   at   high   rpm must be avoided Reason: The high temperature of the oil, a result of clutch disk    heating,    will    cause    deterioration    of    the torque  converter  oil  and  damage  in  the   clutch disk. 3. Successive  stalled  driving  must  not  be  done  for more than 30 seconds. Reason The high temperature of the torque converter oil will  hasten  deterioration  of  the  torque  converter oil, oil seal, and O-ring. 2.5.1.  NEUTRAL SWITCH INSPECTION PROCEDURE (When engine does not start) Fig. 4-227.  Neutral Switch Inspection 1.  Connect the wiring of the neutral switch as shown 2.  Turn the starter switch ON. 3.    If  the  engine  can  be  started,  the  neutral  switch  is defective or not engaged-Ðreplace or adjust. 2.5.2.  CHECKING AND CHANGING OIL IN THE TORQUE CONVERTER (1)  Interval or oil check and replacement Check ...................................................................Every 100 hours or every month. First replacement..................................................After 600 hours of operation or 6 month, whichever comes first. Second and subsequent replacements ................Every 1,200 hours of operation or every 12 months, whichever comes first. (2)  Interval of strainer check First check ............................................................After 600 hours of operation or 6 months, whichever comes first. Second  and subsequent  checks ........................Every 1.200 hours or every 12 months, whichever comes first. 4-143