Sierra Marine Parts Catalog

827 18-2451 COMPLETE UPPER GEAR CASE Replaces: 1547-9412A21, 1547-3917A4, 1547-3917A8, 1547-3917A16, 1547-3917A30, 1547-3917A38, 1547-5523A8, 1547-5523A11, 1547-8265A16 For: Alpha I 1.65:1/1.62:1 18-2452 COMPLETE UPPER GEAR CASE Replaces: 1547-9412A22, 1547-5523A67, 1547-8265A17, 1547-9412A36 For: Alpha I 1.84:1/1.81:1 18-2415 GEAR HOUSING ASSEMBLY Replaces: 1623-815822A36 For: Ratios 1.47, 1.62 Gen II (1998 & up), (0L100040 & up) Used with: 18-2400 Complete Lower Gear Case 18-2450 COMPLETE UPPER GEAR CASE Replaces: 1547-9412A20, 1547-3917A13, 1547-3917A21, 1547- 3917A32, 1547-3917A37, 1547-5523A2, 1547-5523A9, 1547-5523A12, 1547-5523A68, 1547-8265A15, 1547-9412A30, 1547-9412A3 5 For: Alpha I 1.5:1/1.47:1 I/O — MERCRUISER - Drive System 18-2453 COMPLETE UPPER GEAR CASE Replaces: 1547-9412A23, 1547-5523A49, 1547-5523A67, 1547-8265A17 For: Alpha I 1.98:1/1.94:1 18-2443 COMPLETE LOWER GEAR CASE Replaces: 1623-8951A43, 1623-4110A4, 1623-4110A6, 1623-4110A13, 1623-5356A3, 1623-5356A18, 1623-5356A19, 1623-5356A20, 1623-8951A2, 1623-8951A14, 1623-8951A19, 1623-8951A23 For: R/MR/ALPHA 1 18-2401 LOWER GEAR HOUSING Replaces: 1623-8951A27, 1623-8951A37, 1623-8951A5, 1623-8951A15 For: MR/ALPHA Style Bore size 3.2635-3.2650. Includes tapered roller bearing for non-tractor 14/28 or 17/28 gears. When installing new gears use 18-2206-1 gear kit which includes tapered roller bearing 18-1156 for tractor 13/21 gears. 18-2416 COMPLETE UPPER GEAR CASE Replaces: 1547-815930A16, 1547-815930A6, 1547-861063A12 For: Alpha Gen II (1991 & UP) for gear ratios 1.47:1, 1.50:1 Used with 18-2411 Drive Shaft Housing Assembly 18-2419 COMPLETE UPPER GEAR CASE Replaces: 1547-815930A13, 1547-815930A3, 1547-861063A6 For: Alpha Gen II (1991 & UP) for gear ratios 1.98:1, 2.40:1 Used with 18-2411 Drive Shaft Housing Assembly 18-2402 LOWER GEAR HOUSING Replaces: 1623-5356A4 For: R Style