TM 10-3930-660-34 3-13. FLYWHEEL HOUSING AND COVER - REPLACE/REPAIR (Cont’d) 2. DISASSEMBLE FLYWHEEL HOUSING (2). a.   Remove two capscrews (9) and cover plate (10) from flywheel housing (2). b.   Remove O-ring plug (11) and O-ring (12).  Discard O-ring (12). c. Remove threaded plug (13). CLEANING See Cleaning Instructions, para. 2-10. INSPECTION See Inspection Instructions, para. 2-11. ASSEMBLY ASSEMBLE FLYWHEEL HOUSING (2). a. Install threaded plug (13). b. Install O-ring plug (11) and new O-ring (12). c. Install cover plate (10) and two capscrews (9). INSTALLATION 1. IF REMOVED,  INSTALL TWO RING DOWELS (7). Drive two ring dowels (7) into cylinder block until they are against bottom of bore. 2. CLEAN AND DRY REAR CRANKSHAFT SEALING SURFACE. Clean and dry rear crankshaft sealing surface with clean lint-free rags. NOTE The oil seal sealing surface on the crankshaft must be clean to help prevent seal leaks 3-91