TM 10-3930-671-24 Lift Chain (Fork Height) Adjustment NOTE It  is  important  to  make  the  lift  chain adjustment check with a rated load to be sure that the  chains  are  stretched to their maximum length. Figure 2.  Typical view of chain anchors. The lift chains are mounted to the chain anchors on the lift  carriage  and  at  the  chain  anchor  rods  near  the  lift cylinder piston head.  The lift chains can be adjusted by loosening or tightening the chain anchor nuts. Lift chains should be adjusted to provide equal tension in each strand of chain. Lift chains are correctly adjusted if the  lower  fork  carriage  rollers  reach  their  end  (lowest) position approximately 0.50 inch (13 mm) from the lower edge of the inner rail.  This also positions the bottom of the forks the same (equal) distance above the floor. 1. To check this dimension, raise the carriage to a height  that  exposes  several  inches  of  the  inner rail at the roller path.  Apply a layer of grease to the   roller   path   on   the   inner   rail.      Lower   the carriage,  pick  up  a  rated  capacity  load,  tilt  the upright back slightly, and raise the load until the carriage  rollers  have  passed  over  the  greased area.  Lower the load completely and remove the load  from  the  forks.  Raise  the  carriage  again  to expose  the  inner  rail.  You  can  now  check  the roller  path  pattern  in  the  grease  and  determine the correct adjustment of the chains. 2. Adjust lift chains as necessary. 3. Inspect  the  lift  chain  anchors  at  both  ends  of chain. Be sure both nuts, for each chain anchor, are in place. Be sure there is a cotter pin in the end of each anchor. 4. As an alternate check procedure, the lift carriage chains should be adjusted so that the bottoms of the   forks   are   0.50   inch   (12.1   mm)   above   the floor. Lift Chain Inspection and Measurement for Wear WARNING Do not attempt to repair a worn chain. Replace   worn   or   damaged   chain   or injury   to   personnel   and   damage   to equipment could result. 1. Inspect  the  lift  chains  every  truck  PM  (50-250 hours). When operating in corrosive environments,    inspect    the    chains    every    50 hours. 2. During  inspection,  check  for  the  following  chain conditions: • Rust and corrosion • Cracked plates • Raised or turned pins • Tight joints • Wear, e.g.  worn pins or holes Figure 3.  Illustration of typical chain wear and damage. 3.    When the pins or holes become worn, the chain becomes longer.   When  a  section  of  chain  is  3 per cent (%) longer than a section of new chain, the chain is worn out and must be discarded. 4.    Chain  wear  can  be  measured  by  using  a  chain scale or a steel tape measure.  When checking chain  wear,  be  sure  to  measure  a  segment  of chain that moves over a sheave. F-499