TM 10-3930-671-24 Lift Mechanism & Controls Be  sure  there  is  adequate  overhead  clearance  before raising  the  upright  or  damage  to   equipment,   or   injury could result. NOTE It is recommended that these tests be conducted with a rated capacity load, if possible. 1. Cycle  (raise  to  full  height  and  then  lower)  the upright at both slow and fast speed, with the rails tilted    slightly    backwards.    Watch    the    upright assembly as it rises. a) All movements of the upright, fork carriage, and lift chains must be even and smooth, without binding or jerking motion. b) Watch for chain wobble  or  looseness;  the chains    should    have    equal    tension    and move smoothly without noticeable wobble. 2. Check for correct function of the lift control lever and  main  hydraulic  valve.  Listen  for   abnormal noise    in    the    hydraulic    valve,    main    hydraulic pump, and system components. 3. If  the  maximum  fork  height  is  not  reached,  this indicates there is an inadequate (low) oil level in the  hydraulic  sump  tank,  severe  binding  within the upright, or chains are too long. 4. Observe    the    upright    assembly:    rails,    rollers, carriage, lift chains, and cylinders as they move. a) The  fork  carriage  should  move  smoothly when  raised  or  lowered  from  any  height position. b) Check  for  binding  or  excessive  free-play (looseness)  between  the  carriage  and  the upright rails and rollers. c) Check for proper sequencing. d) Listen for abnormal noises. e) If   there   is   excessive   clearance   between the rails and channels, the need for upright roller adjustment is indicated. f) If   the   rails   or   carriage   bind   or   hesitate when lowering, this indicates either damaged rollers or incorrect roller adjustment. 5. Check  the  upright  for  excessive  downdrift.  Stop the   fork   carriage   in   an   intermediate   position. Observe  whether  it  holds  its  position  or  slowly drifts   downward.   If   the   fork   carriage   does   not hold  its  position  when  stopped,  the  upright  may have   too   much   downdrift   due   to   wear   of   the cylinder    seals.        Conduct    an    upright    cylinder downdrift test, with rated load, as needed. Refer to Section 2.1, Service Specifications. 6. Test   the   tilt   control.   Check   for   excessive   tilt cylinder drift. Refer to Section 2. 1, Service Specifications and Section 10. 7, Tilt Cylinder Maintenance. 7. Test    the    correct    tilt    cylinder    rod    adjustment (upright   racking).   Check   tilt   cylinder   rod-to-rod end engagement: must have minimum engagement equal to rod diameter. 8. Check for correct fork height adjustment. Auxiliary Function Control If  lift  truck  is  equipped  with  an  optional  attachment,  an additional control lever will be mounted to the right of the tilt  control  lever.  The  lever  must  be  pushed  to  the  right before    moving    it    forward    and    back    to    operate    the attachment,  or  auxiliary  function.  Check  the  control  for correct function by briefly operating the attachment. Push Forward To: Pull Back To: • Lower • Raise • Tilt Forward • Tilt Backward • Rotate to Left • Rotate to Right • Side Shift to Left • Side Shift to Right • Open Clamp • Close Clamp • Extend Push-Pull • Retract Push-Pull F-48