(1) Unscrew and remove stem nut (1), remove ring kit (2) Note ring kit component assembly order. The piston and pin are matched and shall be kept together as an assembly (7).  The piston or pin are not available separately. b. Cleaning.  Refer to paragraph 6-3.a for general cleaning instructions. (1) Clean piston with care.  Do not mar or scratch contact or seating surfaces. Piston ring grooves must be cleaned with care so as not to scratch or mar grooved surfaces.  Use a ring groove cleaner corresponding to groove size for this purpose. c. Inspection.  Refer to paragraph 6-3.b for general inspection instructions..  Refer to Table 6-1 for dimensional inspection. d. Repair or Replacement.  Refer to paragraph 6- 3.c for general repair or replacement instructions. (1) Replace all damaged parts, and parts that do not meet dimensional requirements of Table 6-1, Table of Limits. (2) Replace rings and spacers as a kit (2, Figure 8-18). e. Assembly.  To assemble the fourth stage piston and pin assembly, proceed as follows. (1) Assemble ring kit (2) components onto piston bolt (7) in the order as shown (2, Figure 8-18). (2) Apply 3 to 4 drops Loc-Tite No.  290 (green) or equivalent to stem threads and install stem nut (1).  Tighten nut (1) to 9 foot-pounds torque. 6-22. Clutch and Clutch Housing Group (See Figure 8- 19).  The following paragraphs contain disassembly, cleaning, inspection, repair or replacement, and assembly instructions for the clutch and clutch housing group. a. Disassembly.  Disassemble the clutch and clutch housing group only to the extent necessary to repair or replace a defective part or parts. (1) If not already removed, remove cotter pin (2), clevis pin (3) from yoke (4); separate rod yoke (4) from shaft assembly (12). Loosen nut (5), unscrew and remove rod yoke (4) and nut (5) from clutch rod (1). (2) Remove screws (7), lock washers (8) and remove cover (6).  Loosen cap screws securing throwout yoke (14) to shaft assembly (12), slowly withdraw  shaft assembly  (12) from clutch housing (15) and remove throwout yoke (14) and yoke keys (13). (3) Unscrew and remove fitting (9), coupling (10), and nipple (11) from clutch assembly (28). (4) Remove four cap screws (17) and lock washer (18). Carefully remove clutch housing assembly (15) from engine. (5) Do not remove bushing (16) from housing (I 5) unless replacement is required. (6) Remove cap screw (25), lock washer (26), and drive washer assembly (22) from engine crankshaft.  Do not disassemble the drive washer (22) unless replacement of pin (23) or washer (24) is necessary. (7) Using a gear puller, or equivalent, break clutch assembly loose from engine crankshaft. Slide clutch assembly (28) back on crankshaft until woodruff key (27) is exposed.  Using a pair of needle nose pliers, or equivalent, remove key (27) from recess in crankshaft.  Remove clutch assembly from engine crankshaft. (8) Remove nuts (30), cap screws (31), spacer (32) and clutch collar (33). (9) Remove cotter pins (34), pins (35), washer weights (36) and links (37).  Push out and remove pin (38). (10) Remove cotter pin (40), pin (41) and links (42). Push upward on locking pin (46) against the spring (47), slip small diameter wire through hole in locking pin (46) to hold pin in place.  Grasp the sliding sleeve (39) and the hub (53) and unscrew counter clockwise. (11) Remove drive plates (50), floating plate (49) from hub (53). Remove release springs (51) from hub (53).  Plate pin (52) does not need to be removed, and should be removed only as necessary. b. Cleaning.  Refer to paragraph 6-3.a for general cleaning instructions. 6-29