Round, 6-bolt crankshaft-mounted drive coupler designed for pre-1987 General Motors (GM) marine engines with a 2-piece rear main seal.
Cross-Reference & Interchange Numbers
BrandPart NumberMerCruiser / Mercury76850A2, 38965A1, 38965A2, 32492A2, 32492A3, 32492A5Sierra Marine18-2171GLM Marine11500Mallory Marine9-72502
Technical Specifications
Flange Configuration: 6-bolt round mounting pattern
Overall Diameter: 4-1/2 inches
Bolt Circle Diameter: 3-9/16 inches
Overall Height / Depth: 4-1/2 inches
Engine Type: GM pre-1987 (2-Piece Rear Main Seal)
Common Engine Fitments
Inline 4-Cylinder: Model 120 / 2.5L (153 CID, 1964–1982) and Model 140 / 3.0L (181 CID, 1968–1982).
V6: Model 185 (229 CID 4bbl, 1983–1984).
V8: Model 228 (305 CID) and Model 260 (350 CID) from 1977 to 1982.
Important Fitment Notes
Triangular Coupler Exclusion: Does not replace drive setups using a triangular 3-bolt coupler (typically found on 1-piece rear main seal flywheels).
Alignment Requirement: Always check engine-to-gimbal bearing alignment with a MerCruiser alignment tool after installation to avoid stripping the coupler splines.
