SERVICE MANUAL CONNECTING RODS, PISTONS, RINGS & SLEEVES Section 5 1. If  the  sleeve  is  hardened,  a  two  tone  gray pattern*   will   result   with   a   sharp   line   of demarkation between the two colors. 2. If the sleeve is unhardened, the etched area will be one solid dark gray color. c. Immediately    after    etching,    neutralize    the etched area with water and then coat it with oil. * The reason for the two-tone gray pattern in  hardened  sleeves  is  that  the  sleeves are   not   hardened   at   the   extreme   end. The   soft   area   extends   into   the   sleeve approximately   1/4   Inch.      When   etched with nital, the soft area will be light gray and the hard area will be dark gray. Inspect Crankcase as follows: 1. Check  the  crankcase  counterbore  depth  with  depth gauge  (1,  Fig.    22),  1  020  560  R91,  at  four  points around the counter-bore (2) as shown in Fig.  22. Figure 22.  - Checking Crankcase Counterbore Depth 1.  Depth gauge 2.  Counterbore a. Maximum variation between points of measurement    before    resurfacing    is    0.03 mm (0.001 in.). b.  Resurface the counterbore using counterboring  tool  (No.    1  020  57491)  as shown  if  Fig.    23.    The  following  are  basic components  of  the  counterboring  tool  and are used in combination with the proper tool holder: I.H. Part No. Description 1 020 553 R91 Driver Unit, Handle & Tool Bits 1 020 554 R1 Adapter Plate 1 020 556 R1 Tool Holder (300 Series) 1 020 555 R1 Tool Holder (400 Series) Figure 23.  - Counterboring Tool Installed in Crankcase 2. Assemble the Counterboring Tool as follows: a. Select   the   proper   tool   holder.      Wipe   all finished  surfaces  clean.    Line  up  zero  on the   driver   unit   with   zero   on   the   adapter plate. b. Install adapter plate (6, Fig.  24) onto driver unit  (3)  with  four  cap  screws  (4)  provided with the unit.. c. Install   tool   holder   (7)   onto   driver   unit   (3) allowing   keyway   in   tool   holder   to   engage over woodruff key. d. Fasten tool holder (7) onto driver  unit  shaft with   cap   screw   (8).      Be   sure   washer   is between cap screw and tool holder. CGES-185-3 PRINTED IN UNITED STATES OF AMERICA Page 22