TM 5-3895-382-24 Bearing Clearance - Check SMCS Code: 1203-535; 1219-535 Measurement Procedure Table 40 Required Tools Part Tool Number Part Description Qty A - Plastigage - NOTICE Keep all parts clean from contaminants. Contaminants    may    cause    rapid    wear    and    shortened component life. NOTE: Caterpillar  does  not  recommend  the  checking  of the    actual    bearing    clearances    particularly    on small engines.  This is because of the possibility of obtaining inaccurate results and the possibility of  damaging  the  bearing  or  the  journal  surfaces. Each Caterpillar engine bearing is quality checked for specific wall thickness. NOTE: The measurements should be within specifications and  the  correct  bearings  should  be  used.    If  the crankshaft  journals  and  the  bores  for  the  block and the rods were measured during disassembly, no further checks are necessary.  However, if the technician   still   wants   to   measure   the   bearing clearances,   Tool   (A)   is   an   acceptable   method. Tool  (A)  is  less  accurate  on  journals  with  small diameters  if  clearances  are  less  than  0.10  mm (.004 inch). NOTICE Lead  wire,  shim  stock  or  a  dial  bore  gauge  can  damage the bearing surfaces. 1. The  technician  must  be  very  careful  to  use  Tool  (A) correctly.  The following points must be remembered: a. Ensure that the backs of the bearings and the bores am clean and dry. b. Ensure   that   the   bearing   locking   tabs   am   properly seated in the tab grooves. c. The  crankshaft  must  be  free  of  oil  at  the  contact points of Tool (A). d. Put  a  piece  of  Tool  (A)  on  the  crown  of  the  bearing that  is  in  the  cap.    Do  not  allow  Tool  (A)  to  extend over the edge of the bearing. e. Use the correct torque-turn specifications in order to install the bearing cap.  Do not use an impact wrench. Be careful not to dislodge the bearing when the cap is installed. f. Do not turn the crankshaft when Tool (A) is installed. Illustration 227 Typical example. g. Carefully remove the cap, but do not remove Tool (A). Measure the width of Tool (A) while Tool (A) is in the bearing  cap  or  on  the  crankshaft  journal.    Refer  to Illustration 227. h. Remove all of Tool (A) before you install the bearing cap. NOTE: When    Tool    (A)    is    used,    the    readings    can sometimes  be  unclear  For  example,  all  parts  of Tool  (A)  are  not  the  same  width.    Measure  the major width in order to ensure that the parts are within the specification range. 7-88