Manifold Assembly Connector Kit – Fits Mercruiser Alpha One Gen 2 & Bravo I/II/III (Replaces 8M0137703, 98825A4, 8M0080805)
Manifold Assembly Connector Kit – Fits Mercruiser Alpha One Gen 2 & Bravo I/II/III (Replaces 8M0137703, 98825A4, 8M0080805) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Manifold Assembly Connector Kit – Fits Mercruiser Alpha One Gen 2 &...
Product Details
This Mercruiser Manifold Assembly Connector Kit is designed for the hydraulic trim system on Mercruiser Alpha One Gen 2 and Bravo I, II, and III stern drives manufactured from 1983 and up. It provides a reliable connection point for stern drive trim lines, ensuring proper hydraulic function and preventing leaks.
It serves as a direct replacement for Mercury/Quicksilver part numbers 8M0137703 and 8M0080805, Mercury 98825A4 and 98825A12, GLM 21970, and Sterndrive Engineering 9F-116-17K.
- Connects hydraulic trim lines at the transom.
- Constructed from durable aluminum for corrosion resistance.
- Includes essential gaskets and hardware for a complete installation.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Mercury/Quicksilver | 8M0137703 |
| Mercury/Quicksilver | 8M0080805 |
| Mercury | 98825A4 |
| Mercury | 98825A12 |
| GLM | 21970 |
| Sterndrive Engineering | 9F-116-17K |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
| Brand | Model | Years | OEM Part No. | Notes |
|---|---|---|---|---|
| Mercruiser | Alpha One Gen 2 | 1983 and up | 98825A4/8M0137703 | Stern drive trim connector |
| Mercruiser | Bravo I | 1983 and up | 98825A4/8M0137703 | Stern drive trim connector |
| Mercruiser | Bravo II | 1983 and up | 98825A4/8M0137703 | Stern drive trim connector |
| Mercruiser | Bravo III | 1983 and up | 98825A4/8M0137703 | Stern drive trim connector |
| Mercruiser | R/MR | 1983 and up | 98825A4/8M0137703 | Stern drive trim connector |
| Mercruiser | MC-1 | 1983 and up | 98825A4/8M0137703 | Stern drive trim connector |
Technical Specs
- Product Type
- Manifold Assembly Connector Kit
- Installation
- Stern drive trim system connection
- Connection
- Hydraulic trim line connection
- Housing Material
- Aluminum
- Housing Color
- Silver/Metallic
- Fitting Type
- Threaded manifold assembly
- Other Technical Attributes
- For stern drive trim systems
What’s in the Box
- 1 x Plate
- 1 x Junction Block Body
- 2 x Gaskets
- 2 x Lockwashers
- 2 x Mounting Bolts
Installation Notes
- Disconnect the boat's battery and ensure the stern drive is in a safe, supported position.
- Relieve any hydraulic pressure from the trim system according to your service manual.
- Carefully disconnect the hydraulic lines from the old manifold assembly. Have rags ready to catch residual fluid.
- Unbolt and remove the old manifold block and plate from the transom.
- Thoroughly clean the mounting surface to ensure a proper seal with the new gasket.
- Place the new gasket and manifold plate, followed by the junction block body.
- Secure the assembly with the new mounting bolts and lockwashers, tightening to the manufacturer's specified torque.
- Reconnect the hydraulic trim lines to the new manifold.
- Reconnect the battery, top off the trim fluid reservoir, and bleed the system of air.
- Test the trim system for smooth operation and check thoroughly for any leaks.
Troubleshooting & FAQ
How do I know if my trim connector manifold is failing?
Signs of a failing manifold include visible hydraulic fluid leaks around the transom, a spongy or unresponsive trim system, or difficulty maintaining the drive's trim position. Corrosion or cracks on the old manifold block are also clear indicators that replacement is needed.
Will this fit an Alpha One Gen 1 drive?
This kit is specifically designed for Alpha One Gen 2 and Bravo series drives from 1983 and later. While some parts may seem similar, using it on a Gen 1 or other unlisted model is not recommended due to potential differences in fit and sealing.
Is it necessary to replace the gaskets and bolts?
Yes. The included gaskets are critical for creating a leak-proof seal between the manifold and the transom assembly. The new bolts and lockwashers ensure correct torque and secure fastening. Reusing old hardware can lead to leaks and system failure.
Do I need a special tool for this installation?
Standard mechanical tools, including a socket/wrench set and a torque wrench, are typically sufficient. You will also need the appropriate line wrenches for the hydraulic fittings to prevent rounding them off. Always refer to your Mercruiser service manual for specific tool recommendations and torque values.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.
Shipping speed & cost?
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns?
Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.
Safety & Important Info
- Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
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