Genuine MerCruiser Flywheel Housing Assembly - Part Number: 12675A5
A genuine used MerCruiser flywheel housing assembly, commonly described in used listings as a bell housing, for selected Alpha-drive petrol engines.
The housing bolts to the rear of the engine block and supports the rear engine-mount and drive-coupler area. Casting identification 12675-C1 is associated with the original assembly.
⚙️ Key Features
Genuine Mercury MerCruiser OEM flywheel housing
Correct original assembly number 12675A5
Associated casting number 12675-C1
Superseded by service assembly 865657A03
Used across selected inline-four, V6 and small-block V8 Alpha applications
🚤 Compatibility
Commonly used on
MerCruiser petrol engines coupled to Alpha-family sterndrives
Rear engine-mount and drive-coupler installations using the 12675 housing
Typically suits
Engine models:
MerCruiser 2.5L / 120HP inline four-cylinder applications where 12675A5 is specified
MerCruiser 5.0L and 5.7L GM small-block V8 Alpha applications using the corresponding rear housing
HP Range: Engine-family controlled
Engine Type: MerCruiser petrol inline-four, V6 and small-block V8 sterndrive engine
Year Range: Approximately 1980s - 1990s
🔌 Function
The flywheel housing aligns the engine with the sterndrive coupler, provides rear structural support and carries the rear engine-mount locations. Accurate alignment is essential to prevent coupler and gimbal-bearing wear.
⚠️ Common Signs of Failure
Housing is cracked around the mounts or bolt bosses
Corrosion damages the mating face
Rear mounts become loose or distorted
Engine-to-drive alignment cannot be set correctly
Coupler or gimbal bearing wears repeatedly because the housing is misaligned
