TM 9-2815-237-34 2-56          Change 1 2-18.   CONNECTING ROD AND PISTON REPAIR (Cont’d) d.  Assembly NOTE • For general assembly instructions, refer to para. 2-12. • Top compression ring is thicker than second compression ring. • If proper end gap cannot be obtained, refer to para. 2-45, table 2-4 or 2-5 for piston-to-cylinder applications.  Refer to para. 2-16.d. for cylinder block repair. 1. Place top compression ring (1) in cylinder bore (13) in which it will be used. 2. Slide piston ring (1) 1 in. (25.4 mm) into cylinder bore (13). Be sure piston ring (1) is square with cylinder bore (13). 3. Check gap in piston ring (1) using feeler gauge. 4. Top compression ring (1) end gap must be 0.012-0.022 in. (0.30-0.55 mm). If not, replace ring (1) and check gap. 5. Repeat steps 1 through 3 using second compression ring (2). End gap must be 0.030-0.039 in. (0.75-1.00 mm). If not, replace ring (2) and check gap. NOTE Spring must be removed from oil ring when checking end gap. 6. Repeat steps 1 through 3 using oil ring (4). End gap must be 0.010-0.020 in. (0.25-0.51 mm). If not, replace ring (4) and check gap. Reinstall spring (3). 7. Repeat steps 1 through 6 for remaining piston rings. 8. Install connecting rod (7) in piston (5) so that identification number (8) and depression (12) on top of piston (5) are on the same side. 9. Coat piston pin (11) with OE/HDO and install in piston (5) and connecting rod (7) and secure with two snaprings (6). 10. Using piston ring expander, install oil ring (4) on piston (5). 11. Using piston ring expander, install second compression ring (2) on piston (5). Be sure marked side of piston ring (2) faces up. 12. Using piston ring expander, install top compression ring (1) on piston (5). Be sure marked side of piston ring (1) faces up. 13. Install rod cap (10) on connecting rod (7) and secure with two nuts (9). 14. Repeat steps 8 through 13 for remaining pistons and connecting rods.