SERVICE MANUAL CONNECTING RODS, PISTONS, RINGS & SLEEVES Section 5 NOTE:    If  all  counterbore  ledges  of  one  particular engine  are  to  be  counterbored  to  the  same  depth, take  measurement  of  aft  counterbores  and  set  up counterboring  tool  on  lowest  counterbore  ledge,  to insure clean-up of all counterbores. c. Hold onto handle (1) and pull out on plunger (9). d. Slowly   and   gently   lower   tool   holder   into counterbore,  to  avoid  damage  to  the  tool bit. e. Engage  larger  diameter  of  tool  holder  into counterbore   and   allow   tool   bit   to   rest   on counterbore ledge. f. Loosen    locking     screw     (10)     and     rotate adjusting nut (2) in a CLOCK-WISE DIRECTION until tool bit clears the counterbore ledge. g. Tighten locking screw. h. Assemble hold-down cap screws and washers  (5)  through  adapter  plate  (6)  into cylinder block finger-tight. i. Tool holder must rotate freely. j. Torque  cap  screws  to  45  N•m  (33  Ibf-ft). Tighten    each    cap    screw    only    a    small amount  before  final  torquing.    Then  cross- tighten in diagonal sequence. 6.Measure depth of counterbore as follows: a. Using   a   depth   micrometer   (1,   Fig.   26) measure from the top surface of adapter (2) to    deck    of    crankcase    (3)    and    record measurement. b. Then, measure from top surface of adapter plate  to  counterbore  ledge  (4)  and  record measurement. c. Subtract No. 1 reading from No.  2 reading, and  this  is  the  depth  of  the  counterbore ledge as exemplified below. EXAMPLE: No.  1 Reading - Top of Adapter Plate to Counterbore Ledge 2.125" No.  2 Reading - Top of Adapter Plate to Deck of Cylinder Block -1.750" Depth of Counterbore = .375" Figure 26.  - Depth Measurement of Counterbore 1.  Depth micrometer 2.  Adapter plate 3.  Deck of engine block 4.  Counterbore ledge 7.Operate counterboring tool as follows: a. Loosen locking screw (1, Fig.  27). b. Rotate     adjusting     nut     (2)     in     counter- clockwise direction until tool bit is resting on the  lowest  part  of  the  counterbore  ledge and there is clearance between the housing (5) and the adjusting nut. c. The   distance   between   the   housing   and adjusting nut equals the amount of material that  will  be  removed  from  the  counterbore ledge. d. The  adjusting  nut  has  graduated  markings to  estimate  the  amount  of  the  cut.    Each mark is 0.03 mm (0.001 in.) NOTE: Never attempt to remove more than 0.13 mm (0.005 in.) of material at one setting. CGES-185-3 PRINTED IN UNITED STATES OF AMERICA Page 24